Trouble Reconnecting Peripherals after Disconnection.

RE: Trouble Reconnecting Peripherals after Disconnection.

Hung Bui — Thu, 02 Jan 2025 16:09:40 GMT

Hi,
If you want to see what cause the error, switch the project from Release to Debug.

If you don't have that option you can try adding DEBUG to preprocessor symbols.

Please try to test without bonding/security from what you provided it seems bonding was still used ?
evt_id=5 = PM_EVT_CONN_SEC_CONFIG_REQ.

RE: Trouble Reconnecting Peripherals after Disconnection.

siltvm — Tue, 24 Dec 2024 05:50:08 GMT

Hung Bui ,Vidar Berg ,I modified the following parameters:

Central Link Count:

// <o> NRF_SDH_BLE_CENTRAL_LINK_COUNT - Maximum number of central links.
#ifndef NRF_SDH_BLE_CENTRAL_LINK_COUNT
#define NRF_SDH_BLE_CENTRAL_LINK_COUNT 10
#endif

Peripheral Link Count:

// <o> NRF_SDH_BLE_PERIPHERAL_LINK_COUNT - Maximum number of peripheral links.
#ifndef NRF_SDH_BLE_PERIPHERAL_LINK_COUNT
#define NRF_SDH_BLE_PERIPHERAL_LINK_COUNT 1
#endif

Total Link Count:

// <o> NRF_SDH_BLE_TOTAL_LINK_COUNT - Total link count.
// <i> Maximum number of total concurrent connections using the default configuration.
#ifndef NRF_SDH_BLE_TOTAL_LINK_COUNT
#define NRF_SDH_BLE_TOTAL_LINK_COUNT 11
#endif

RAM Starting Address: 0x2000B198

After these changes, I observed the following behavior:

When Device 1 and Device 2 are connected, disconnecting Device 2 results in the following log output:

03:06.626 -> <info> app: SCAN START
03:06.626 -> <info> app: Device disconnected, conn_handle: 0x0, reason: 0x8
03:06.626 -> <info> app: Erase bonds!
03:06.626 -> <info> app: ENTER PM EVENT HANDLER: evt_id=12
03:06.626 -> <info> peer_manager_handler: All peers deleted.
03:06.626 -> <info> app: nrf_ble_scan_start : 0
03:06.626 -> 
03:06.626 -> <info> app: SCAN START
03:06.626 -> <error> app: Fatal error
03:06.626 -> <warning> app: System reset 

Following the system reset, the gateway attempts to connect to two nearby available peripherals.

I'm seeking assistance in understanding the root cause of this "Fatal error" and subsequent system reset .

RE: Trouble Reconnecting Peripherals after Disconnection.

siltvm — Mon, 23 Dec 2024 10:08:11 GMT

Hung Bui

When I am checking the NRF log for further clarification, I observed that when Device 1 connected, there are some events that happened inside the peer_manager_event_handler. These are:

02:59.010 -> <info> app: ENTER PM EVENT HANDLER: evt_id=5
02:59.010 -> <info> app: ENTER PM EVENT HANDLER: evt_id=1
02:59.010 -> <info> app: ENTER PM EVENT HANDLER: evt_id=5

But if Device 2 is connected, these events do not happen. Is my bonding removal in the gateway code not properly done ?.

I will attach my log console output.

Here, my Device 1 MAC ID is E81D0E54B577,

Device 2 MAC ID is D37CF00CAD14,

the NRF Connect apk installed phone MAC ID is 7E50F95DCE9F.

12:02:55.495 -> <info> app_timer: RTC: initialized.

12:02:55.495 -> <info> app: nrf_sdh_enable_request : 0
12:02:55.495 -> 

12:02:55.495 -> <info> app: nrf_sdh_ble_default_cfg_set : 0
12:02:55.495 -> 

12:02:55.495 -> <info> app: nrf_sdh_ble_enable : 0
12:02:55.495 -> 

12:02:55.495 -> <info> app:  after nrf sdh ble observer 
12:02:55.495 -> 

12:02:55.495 -> <info> app: nrf_ble_scan_init : 0
12:02:55.495 -> 

12:02:55.495 -> <info> app: scan filter init HART_RATE_SERVICE_UUID_IDX : 0
12:02:55.495 -> 

12:02:55.495 -> <info> app: scan filter init RSCS_SERVICE_UUID_IDX : 0
12:02:55.495 -> 

12:02:55.495 -> <info> app: scan filter init NUS : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: nrf_ble_scan_filters_enable : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: nrf_ble_gatt_init : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: nrf_ble_gatt_att_mtu_central_set : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: nrf_ble_gatt_att_mtu_periph_set : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: ble_db_discovery_init :0
12:02:55.542 -> 

12:02:55.542 -> <info> app: ble_hrs_c_init : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: ble_rscs_c_init : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: ble_nus_c_init for instance 0: 0

12:02:55.542 -> <info> app: ble_nus_c_init for instance 1: 0

12:02:55.542 -> <info> app: nrf_ble_qwr_init : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: nrf_ble_qwr_init : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: nrf_ble_qwr_init : 0
12:02:55.542 -> 

12:02:55.542 -> <info> app: ble_hrs_init : 0
12:02:55.588 -> 

12:02:55.588 -> <info> app: ble_rscs_init : 0
12:02:55.588 ->  

12:02:55.588 -> <info> app:  ble_nus_init : 0
12:02:55.588 -> 

12:02:55.588 -> <info> app: Relay example started.

12:02:55.588 -> <info> app: ADV_SCAN_START

12:02:55.588 -> <info> app: nrf_ble_scan_start : 0
12:02:55.588 -> 

12:02:55.588 -> <info> app: SCAN START

12:02:55.588 -> <info> app: Fast advertising.

12:02:57.276 -> <info> app: Connected to target E81D0E54B577

12:02:57.276 -> <info> app: Central connected

12:02:57.276 -> <info> app: Attempt to find HRS, RSC, or NUS conn_handle 0x0

12:02:57.276 -> <info> app: NUS client assigned to conn_handle 0x0 (index: 0)

12:02:57.276 -> <info> app: nrf_ble_scan_start : 0
12:02:57.276 -> 

12:02:57.276 -> <info> app: SCAN START

12:02:57.322 -> <info> app: ATT MTU exchange completed.

12:02:57.322 -> <info> app: Ble NUS max data length set to 0xF4(244)

12:02:59.010 -> <info> app: HRS discovered on conn_handle 0x0

12:02:59.010 -> <info> app: ENTER PM EVENT HANDLER: evt_id=5

12:02:59.010 -> <info> app: ENTER PM EVENT HANDLER: evt_id=1

12:02:59.010 -> <info> app: Running Speed and Cadence service discovered on conn_handle 0x0

12:02:59.010 -> <info> app: ENTER PM EVENT HANDLER: evt_id=5

12:02:59.010 -> <info> app: current instance index 0
12:02:59.010 -> 

12:02:59.010 -> <info> app: Discovery complete ble_nus_c_evt_handler

12:02:59.010 -> <info> app: Connected to device with Nordic UART Service.

12:02:59.056 -> <info> app: DB Discovery instance 0x2000477C available on conn handle: 0

12:02:59.056 -> <info> app: Found 3 services on conn_handle: 0

12:03:00.041 -> <info> app: Connected to target D37CF00CAD14

12:03:00.041 -> <info> app: Central connected

12:03:00.041 -> <info> app: Attempt to find HRS, RSC, or NUS conn_handle 0x1

12:03:00.087 -> <info> app: NUS client assigned to conn_handle 0x1 (index: 1)

12:03:00.275 -> <info> app: ATT MTU exchange completed.

12:03:00.275 -> <info> app: Ble NUS max data length set to 0xF4(244)

12:03:01.915 -> <info> app: current instance index 1
12:03:01.915 -> 

12:03:01.915 -> <info> app: Discovery complete ble_nus_c_evt_handler

12:03:01.915 -> <info> app: Connected to device with Nordic UART Service.

12:03:01.915 -> <info> app: DB Discovery instance 0x20004D4C available on conn handle: 1

12:03:01.915 -> <info> app: Found 3 services on conn_handle: 1

12:05:55.299 -> <info> app: Fast advertising.

12:05:55.299 -> <info> app: BLE ADV EVT IDLE
12:05:55.299 -> 

12:06:08.609 -> <info> app: Connected to target 7E50F95DCE9F

12:06:08.609 -> <info> app: Peripheral connected

12:06:08.796 -> <info> app: ATT MTU exchange completed.

12:06:08.796 -> <info> app: Ble NUS max data length set to 0xF4(244)

12:17:17.625 -> <info> app: current instance index 1
12:17:17.625 ->

RE: Trouble Reconnecting Peripherals after Disconnection.

Hung Bui — Mon, 23 Dec 2024 08:50:18 GMT

Hi,

Thanks for more info.
Now we will need to debug this step by step. After you get the device 1 re-connected you couldn't connect to Device 2. We will need to check why it couldn't connect to Device 2.

1. Check if it can scan for device 2 advertising packet

2. If it can scan for device 2 advertising packet, we will need to check if it send the connect request to device 2 or if there is any error that the code doesn't call the connection function, or if the connect function is called but the actual radio packet is not sent.

3. If it can not scan for device 2 advertising packet , we will need to check why. If device 2 actually send anything or if for some reason the central can't scan. We will need to check if it scan for other device (not Device 1 or 2)

CURRENT ROLE : 00 means that the device is scanning not in peripheral or central role.

I suspect there could be an issue with the total link count, please try to increase the following:
NRF_SDH_BLE_TOTAL_LINK_COUNT

NRF_SDH_BLE_CENTRAL_LINK_COUNT

NRF_SDH_BLE_PERIPHERAL_LINK_COUNT

This is just to test to narrow down the issue. Please try to increase these setting in sdk_config.h by at least one.

RE: Trouble Reconnecting Peripherals after Disconnection.

siltvm — Mon, 23 Dec 2024 04:44:55 GMT

Hung Bui ,

I just removed the bonding parts from peripheral as well as central in peer manager initializations, so there are no errors like security failures currently present.

If I turn off the device that I can able to connect to, then the device that couldn't connect can able to connect into the gateway. That is actually a little bit more confusing part.

That is, if I have two devices, Device 1 and Device 2. Assume that Device 1 connects first, then Device 2 connects secondly into the gateway. If I am disconnecting the two devices and then powering them again, I can able to connect only the first connected device (Device 1), the second connected device (Device 2) couldn't able to connect to the gateway. If I am powering off the firstly connected peripheral, then there is only Device 2 advertising during this time, and the gateway can able to connect into Device 2.

What is happening here? What could be the reason for the issue?

RE: Trouble Reconnecting Peripherals after Disconnection.

Hung Bui — Fri, 20 Dec 2024 15:02:04 GMT

Hi,

Have you read my first reply ?
If you look at the log you can find this:
12:13:10.443 -> <info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Bonding, error: 133

Error 133 is BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP. So either the central or the peripheral has responded that pairing is not supported.

You can test by disabling bonding and see if the issue still occurs.

If it stops, we need to look into which device causing the issue, a sniffer trace can help here.
Have you made sure you connect to the correct device not other random device around ?
How did you recover from the situation, how did you connect to the 2 devices that you couldn't connect ?

What you can do is to turn off any device that you still can connect and leave only the device that you can not connect. Try to use the log to see if the central can scan for the advertising packet and check if it can send connect request, then sniffer trace to capture the communication.

Pay attention to the log 12:13:08.334 -> <info> peer_manager_handler: Connection security failed: to see if it occurs when testing

RE: Trouble Reconnecting Peripherals after Disconnection.

siltvm — Fri, 20 Dec 2024 14:33:18 GMT

Hung Bui ,

In here, we changed bonding and security encryption in the peer_manager_init() function, but it did not solve the issue. Initially, I was able to connect the gateway with two peripherals, and the gateway could connect with the nrfconnect app and send/receive data. However, if I disconnected the second connected peripheral from the gateway and powered it again, it would not connect with the gateway. But if I reconnected the first connected peripheral with the gateway, I could connect with it without any issues. The trouble only happens with the second connected peripheral.

If I restart the gateway, I am able to connect with both peripherals. What could be the issue? I checked the ble_event_handler role and obtained 'CURRENT ROLE: 00'

19:40:03.950 -> <info> app_timer: RTC: initialized.

19:40:03.950 -> <info> app: nrf_sdh_enable_request : 0
19:40:03.950 -> 

19:40:03.950 -> <info> app: nrf_sdh_ble_default_cfg_set : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: nrf_sdh_ble_enable : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app:  after nrf sdh ble observer 
19:40:03.997 -> 

19:40:03.997 -> <info> app: nrf_ble_scan_init : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: scan filter init HART_RATE_SERVICE_UUID_IDX : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: scan filter init RSCS_SERVICE_UUID_IDX : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: scan filter init NUS : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: nrf_ble_scan_filters_enable : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: nrf_ble_gatt_init : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: nrf_ble_gatt_att_mtu_central_set : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: nrf_ble_gatt_att_mtu_periph_set : 0
19:40:03.997 -> 

19:40:03.997 -> <info> app: ble_db_discovery_init :0
19:40:03.997 -> 

19:40:03.997 -> <info> app: ble_hrs_c_init : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: ble_rscs_c_init : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: ble_nus_c_init for instance 0: 0

19:40:04.044 -> <info> app: ble_nus_c_init for instance 1: 0

19:40:04.044 -> <info> app: nrf_ble_qwr_init : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: nrf_ble_qwr_init : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: nrf_ble_qwr_init : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: ble_hrs_init : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: ble_rscs_init : 0
19:40:04.044 ->  

19:40:04.044 -> <info> app:  ble_nus_init : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: Relay example started.

19:40:04.044 -> <info> app: ADV_SCAN_START

19:40:04.044 -> <info> app: nrf_ble_scan_start : 0
19:40:04.044 -> 

19:40:04.044 -> <info> app: SCAN START

19:40:04.044 -> <info> app: Fast advertising.

19:40:04.091 -> <info> app: CURRENT ROLE : 00

19:40:05.168 -> <info> app: Connected to target E81D0E54B577

19:40:05.168 -> <info> app: CURRENT ROLE : 02

19:40:05.168 -> <info> app: Central connected

19:40:05.168 -> <info> app: Attempt to find HRS, RSC, or NUS conn_handle 0x0

19:40:05.168 -> <info> app: NUS client assigned to conn_handle 0x0 (index: 0)

19:40:05.168 -> <info> app: nrf_ble_scan_start : 0
19:40:05.168 -> 

19:40:05.168 -> <info> app: SCAN START

19:40:05.168 -> <info> app: CURRENT ROLE : 02

19:40:05.215 -> <info> app: CURRENT ROLE : 00

19:40:05.215 -> <info> app: CURRENT ROLE : 00

19:40:05.215 -> <info> app: ATT MTU exchange completed.

19:40:05.215 -> <info> app: Ble NUS max data length set to 0xF4(244)

19:40:05.215 -> <info> app: CURRENT ROLE : 02

19:40:05.262 -> <info> app: CURRENT ROLE : 00

19:40:05.262 -> <info> app: CURRENT ROLE : 00

19:40:05.403 -> <info> app: CURRENT ROLE : 00

19:40:05.403 -> <info> app: CURRENT ROLE : 00

19:40:05.403 -> <info> app: CURRENT ROLE : 00

19:40:05.403 -> <info> app: CURRENT ROLE : 00

19:40:05.497 -> <info> app: CURRENT ROLE : 02

19:40:05.778 -> <info> app: CURRENT ROLE : 00

19:40:05.778 -> <info> app: CURRENT ROLE : 00

19:40:05.778 -> <info> app: CURRENT ROLE : 00

19:40:05.778 -> <info> app: CURRENT ROLE : 00

19:40:05.825 -> <info> app: CURRENT ROLE : 00

19:40:05.918 -> <info> app: CURRENT ROLE : 02

19:40:06.199 -> <info> app: CURRENT ROLE : 02

19:40:06.481 -> <info> app: CURRENT ROLE : 02

19:40:06.809 -> <info> app: CURRENT ROLE : 02

19:40:06.949 -> <info> app: Connected to target D37CF00CAD14

19:40:06.949 -> <info> app: CURRENT ROLE : 02

19:40:06.949 -> <info> app: Central connected

19:40:06.996 -> <info> app: Attempt to find HRS, RSC, or NUS conn_handle 0x1

19:40:06.996 -> <info> app: NUS client assigned to conn_handle 0x1 (index: 1)

19:40:07.090 -> <info> app: CURRENT ROLE : 02

19:40:07.253 -> <info> app: CURRENT ROLE : 02

19:40:07.394 -> <info> app: CURRENT ROLE : 02

19:40:07.536 -> <info> app: CURRENT ROLE : 02

19:40:07.585 -> <info> app: CURRENT ROLE : 02

19:40:07.585 -> <info> app: ATT MTU exchange completed.

19:40:07.585 -> <info> app: Ble NUS max data length set to 0xF4(244)

19:40:07.585 -> <info> app: CURRENT ROLE : 02

19:40:07.667 -> <info> app: CURRENT ROLE : 02

19:40:07.720 -> <info> app: HRS discovered on conn_handle 0x0

19:40:07.720 -> <info> app: ENTER PM EVENT HANDLER: evt_id=5

19:40:07.720 -> <info> app: ENTER PM EVENT HANDLER: evt_id=1

19:40:07.720 -> <info> app: Running Speed and Cadence service discovered on conn_handle 0x0

19:40:07.720 -> <info> app: ENTER PM EVENT HANDLER: evt_id=5

19:40:07.720 -> <info> app: current instance index 0
19:40:07.720 -> 

19:40:07.720 -> <info> app: Discovery complete ble_nus_c_evt_handler

19:40:07.720 -> <info> app: Connected to device with Nordic UART Service.

19:40:07.720 -> <info> app: DB Discovery instance 0x2000477C available on conn handle: 0

19:40:07.764 -> <info> app: Found 3 services on conn_handle: 0

19:40:07.764 -> <info> app: CURRENT ROLE : 02

19:40:07.814 -> <info> app: CURRENT ROLE : 02

19:40:07.850 -> <info> app: CURRENT ROLE : 02

19:40:07.935 -> <info> app: CURRENT ROLE : 02

19:40:08.077 -> <info> app: CURRENT ROLE : 02

19:40:08.177 -> <info> app: CURRENT ROLE : 02

19:40:08.260 -> <info> app: CURRENT ROLE : 02

19:40:08.474 -> <info> app: CURRENT ROLE : 02

19:40:08.521 -> <info> app: CURRENT ROLE : 02

19:40:08.568 -> <info> app: CURRENT ROLE : 02

19:40:08.661 -> <info> app: CURRENT ROLE : 02

19:40:08.708 -> <info> app: CURRENT ROLE : 02

19:40:08.849 -> <info> app: current instance index 1
19:40:08.849 -> 

19:40:08.849 -> <info> app: Discovery complete ble_nus_c_evt_handler

19:40:08.849 -> <info> app: Connected to device with Nordic UART Service.

19:40:08.849 -> <info> app: DB Discovery instance 0x20004D4C available on conn handle: 1

19:40:08.849 -> <info> app: Found 3 services on conn_handle: 1

19:40:08.896 -> <info> app: CURRENT ROLE : 02

19:40:09.458 -> <info> app: CURRENT ROLE : 02

19:40:36.485 -> <info> app: current instance index 1
19:40:36.485 -> 

19:40:36.485 -> <info> app: Disconnected from instance 1

19:40:36.485 -> <info> app: Scanning filters disabled.

19:40:36.485 -> <info> app: NUS UUID filter set.

19:40:36.485 -> <info> app: Scanning filters enabled.

19:40:36.485 -> <info> app: nrf_ble_scan_start : 0
19:40:36.485 -> 

19:40:36.485 -> <info> app: SCAN START

19:40:36.485 -> <info> app: CURRENT ROLE : 02

19:40:36.532 -> <info> app: Device disconnected, conn_handle: 0x1, reason: 0x8

19:40:36.532 -> <info> app: nrf_ble_scan_start : 0
19:40:36.532 -> 

19:40:36.532 -> <info> app: SCAN START

19:40:36.532 -> <info> app: CURRENT ROLE : 00

19:40:36.532 -> <info> app: CURRENT ROLE : 00

19:40:36.532 -> <info> app: CURRENT ROLE : 00

19:40:36.532 -> <info> app: CURRENT ROLE : 00

thw log output shows this for the further clarifications .

static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{   
   
    uint16_t conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
    uint16_t role        = ble_conn_state_role(conn_handle);
    NRF_LOG_INFO("CURRENT ROLE : %02X",role);
    //NRF_LOG_INFO("enter in ble evt handler \n ");
    // Based on the role this device plays in the connection, dispatch to the right handler.
    if (role == BLE_GAP_ROLE_PERIPH || ble_evt_is_advertising_timeout(p_ble_evt))
    {
        //NRF_LOG_INFO("ble gap role peripherel  \n ");
        ble_hrs_on_ble_evt(p_ble_evt, &m_hrs);
        ble_rscs_on_ble_evt(p_ble_evt, &m_rscs);
        ble_nus_on_ble_evt(p_ble_evt, &m_nus);  // Adding this line for NUS peripheral handling
        on_ble_peripheral_evt(p_ble_evt);
    }
    else if ((role == BLE_GAP_ROLE_CENTRAL) || (p_ble_evt->header.evt_id == BLE_GAP_EVT_ADV_REPORT))
    {
        //NRF_LOG_INFO("ble gap role central   \n ");
       // ble_hrs_c_on_ble_evt(p_ble_evt, &m_hrs_c);
       // ble_rscs_c_on_ble_evt(p_ble_evt, &m_rscs_c);
        for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
        {
          ble_nus_c_on_ble_evt(p_ble_evt, &m_ble_nus_c_arr[i]);
        }
        //ble_nus_c_on_ble_evt(p_ble_evt,&m_ble_nus_c);   // need to check this operation is neccesssary 
        on_ble_central_evt(p_ble_evt);
    }
}

Your response is more valuable

RE: Trouble Reconnecting Peripherals after Disconnection.

Hung Bui — Thu, 19 Dec 2024 13:50:59 GMT

Hi,
Please read what I wrote in last reply and answer the question. Please capture a sniffer trace.
Simply saying "cannot connect to a device" doesn't help the debugging.

RE: Trouble Reconnecting Peripherals after Disconnection.

siltvm — Thu, 19 Dec 2024 13:36:15 GMT

Initially, I mean when the code is flashed into the gateway, I am able to connect to two devices. However, when one of my peripheral devices is disconnected, I cannot connect to a specific device.

I just modified the peer_manager_init() function like this, but it doesn't solve the issue. I am still confused. What is happening here? When I disconnect the two devices at the same time after the peer_manager_init() function, I am still only able to connect to a specific device. The log shows that the scan starts, but it cannot connect to the other peripheral device.

Can you please take a look at my gateway code and tell me if it's correct?

/**@brief Function for initializing the Peer Manager.
 */
static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t err_code;

    // Initialize the Peer Manager.
    err_code = pm_init();
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_init : %d\n", err_code);

    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

    // Security parameters for SEC_OPEN (no encryption, no authentication, no bonding).
    sec_param.bond           = 0; // No bonding.
    sec_param.mitm           = 0; // No MITM protection.
    sec_param.lesc           = 0; // No LE Secure Connections.
    sec_param.keypress       = 0; // No keypress notifications.
    sec_param.io_caps        = BLE_GAP_IO_CAPS_NONE; // No I/O capabilities.
    sec_param.oob            = 0; // No Out-of-Band data.
    sec_param.min_key_size   = 7; // Minimum encryption key size (not enforced for SEC_OPEN).
    sec_param.max_key_size   = 16; // Maximum encryption key size (not enforced for SEC_OPEN).
    sec_param.kdist_own.enc  = 0; // Do not distribute encryption keys.
    sec_param.kdist_own.id   = 0; // Do not distribute identity keys.
    sec_param.kdist_peer.enc = 0; // Do not request encryption keys from peer.
    sec_param.kdist_peer.id  = 0; // Do not request identity keys from peer.

    // Set the security parameters in the Peer Manager.
    err_code = pm_sec_params_set(&sec_param);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_sec_params_set : %d\n", err_code);

    // Register the Peer Manager event handler.
    err_code = pm_register(pm_evt_handler);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_register : %d\n", err_code);
}

RE: Trouble Reconnecting Peripherals after Disconnection.

Hung Bui — Thu, 19 Dec 2024 13:20:39 GMT

Hi,
If you look at the log you can find this:
12:13:10.443 -> <info> peer_manager_handler: Connection security failed: role: Central, conn_handle: 0x0, procedure: Bonding, error: 133

RE: Trouble Reconnecting Peripherals after Disconnection.

siltvm — Thu, 19 Dec 2024 09:59:43 GMT

the given is the peripherl device code , this device is only responsible for taking the advertised device data and send it to connecte gateways .

/**
 * Copyright (c) 2014 - 2020, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
/**
 * @brief BLE Heart Rate and Running Speed relay application main file.
 *
 * @detail This application demonstrates a simple relay, which passes on the values it receives.
 * By combining a collector part on one end and a sensor part on the other,
 * the s130 can function simultaneously as a central and a peripheral device.
 * 
 * The following figure shows how the sensor ble_app_hrs connects and interacts with the relay
 * in the same manner it would connect to a Heart Rate Collector. In this case, the relay
 * application acts as a central.
 *
 * On the other side, a collector (such as Master Control Panel or ble_app_hrs_c) connects
 * and interacts with the relay in the same manner it would connect to a heart rate sensor peripheral.
 *
 * LED layout:
 * LED 1: Central side is scanning.       LED 2: Central side is connected to a peripheral.
 * LED 3: Peripheral side is advertising. LED 4: Peripheral side is connected to a central.
 *
 * @note While testing, make sure that the Sensor and Collector are actually connecting to the relay,
 *       and not directly to each other!
 *
 *    Peripheral                  Relay                    Central
 *    +--------+        +-----------|----------+        +-----------+
 *    | Heart  |        | Heart     |   Heart  |        |           |
 *    | Rate   | -----> | Rate     -|-> Rate   | -----> | Collector |
 *    | Sensor |        | Collector |   Sensor |        |           |
 *    +--------+        +-----------|   and    |        +-----------+
 *                      | Running   |   Running|
 *    +--------+        | Speed    -|-> Speed  |
 *    | Running|------> | Collector |   Sensor |
 *    | Speed  |        +-----------|----------+
 *    | Sensor |
 *    +--------+
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nordic_common.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "app_timer.h"
#include "bsp_btn_ble.h"
#include "ble.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "ble_db_discovery.h"
#include "ble_hrs.h"
#include "ble_rscs.h"
#include "ble_hrs_c.h"
#include "ble_rscs_c.h"
#include "ble_conn_state.h"
#include "ble_nus.h"
#include "ble_nus_c.h"
#include "nrf_fstorage.h"
#include "fds.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_ble_scan.h"
#include "nrf_delay.h"
#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"
#include "display.h"
#include "nrfx_gpiote.h"
//#include "nrf_drv_gpiote.h"

char Bledatabuff[64];

#define PERIPHERAL_ADVERTISING_LED      BSP_BOARD_LED_2
#define PERIPHERAL_CONNECTED_LED        BSP_BOARD_LED_3
#define CENTRAL_SCANNING_LED            BSP_BOARD_LED_0
#define CENTRAL_CONNECTED_LED           BSP_BOARD_LED_1

#define DEVICE_NAME                     "nurse_resp"                                 /**< Name of device used for advertising. */
#define MANUFACTURER_NAME               "NordicSemiconductor"                       /**< Manufacturer. Passed to Device Information Service. */
#define APP_ADV_INTERVAL                300                                         /**< The advertising interval (in units of 0.625 ms). This value corresponds to 187.5 ms. */

#define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

#define APP_BLE_CONN_CFG_TAG            1                                           /**< Tag that identifies the SoftDevice BLE configuration. */

#define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                       /**< Time from initiating event (connect or start of notification) to the first time sd_ble_gap_conn_param_update is called (5 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(30000)                      /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT    3                                           /**< Number of attempts before giving up the connection parameter negotiation. */

#define SEC_PARAM_BOND                  1                                           /**< Perform bonding. */
#define SEC_PARAM_MITM                  0                                           /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC                  0                                           /**< LE Secure Connections not enabled. */
#define SEC_PARAM_KEYPRESS              0                                           /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES       BLE_GAP_IO_CAPS_NONE                        /**< No I/O capabilities. */
#define SEC_PARAM_OOB                   0                                           /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE          7                                           /**< Minimum encryption key size in octets. */
#define SEC_PARAM_MAX_KEY_SIZE          16                                          /**< Maximum encryption key size in octets. */

#define HART_RATE_SERVICE_UUID_IDX      0                                           /**< Hart Rate service UUID index in array. */
#define RSCS_SERVICE_UUID_IDX           1                                           /**< RSCS service UUID index in array. */

#define NUS_SERVICE_UUID_TYPE   BLE_UUID_TYPE_VENDOR_BEGIN              /**< UUID type for the Nordic UART Service (vendor specific). */
/**@brief   Priority of the application BLE event handler.
 * @note    You shouldn't need to modify this value.
 */
#define APP_BLE_OBSERVER_PRIO           3

#define DB_DISCOVERY_INSTANCE_CNT       2  /**< Number of DB Discovery instances. */

#define KEY1 13
#define KEY2 14
#define BUZZ_PIN 20
#define POWER_STS 19
#define BATTERY_ON 22
#define POWER_ON 0
#define POWER_OFF 1
#define CLEAR 0
#define SET 1

static ble_hrs_t m_hrs;                                             /**< Heart Rate Service instance. */
static ble_rscs_t m_rscs;                                           /**< Running Speed and Cadence Service instance. */
static ble_hrs_c_t m_hrs_c;                                         /**< Heart Rate Service client instance. */
static ble_rscs_c_t m_rscs_c; 
                                      /**< Running Speed and Cadence Service client instance. */
BLE_NUS_C_ARRAY_DEF(m_ble_nus_c_arr, NRF_SDH_BLE_CENTRAL_LINK_COUNT);

//BLE_NUS_C_DEF(m_ble_nus_c);                                        /**< BLE Nordic UART Service (NUS) client instance. */
BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                   // peripherel instance of NUS  ( modified )

NRF_BLE_GQ_DEF(m_ble_gatt_queue,                                    /**< BLE GATT Queue instance. */
               NRF_SDH_BLE_CENTRAL_LINK_COUNT,
               NRF_BLE_GQ_QUEUE_SIZE);
NRF_BLE_GATT_DEF(m_gatt);                                              /**< GATT module instance. */
NRF_BLE_QWRS_DEF(m_qwr, NRF_SDH_BLE_TOTAL_LINK_COUNT);                 /**< Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);                                    /**< Advertising module instance. */
BLE_DB_DISCOVERY_ARRAY_DEF(m_db_discovery, 2);                         /**< Database discovery module instances. */
NRF_BLE_SCAN_DEF(m_scan);                                           /**< Scanning module instance. */
static uint16_t m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**< Handle of the current connection. */
static uint16_t m_conn_handle_hrs_c  = BLE_CONN_HANDLE_INVALID;     /**< Connection handle for the HRS central application */
static uint16_t m_conn_handle_rscs_c = BLE_CONN_HANDLE_INVALID;     /**< Connection handle for the RSC central application */
//static uint16_t m_conn_handle_nus_c  = BLE_CONN_HANDLE_INVALID;     /**< Handle of the current connection for the nus  */

static uint16_t m_conn_handle_nus_c_arr[NRF_SDH_BLE_CENTRAL_LINK_COUNT];


static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
/**@brief Names that the central application scans for, and that are advertised by the peripherals.
 *  If these are set to empty strings, the UUIDs defined below are used.
 */
static char const m_target_periph_name[] = "";

/**@brief UUIDs that the central application scans for if the name above is set to an empty string,
 * and that are to be advertised by the peripherals.
 */
static ble_uuid_t m_adv_uuids[] =
{
    {BLE_UUID_HEART_RATE_SERVICE,        BLE_UUID_TYPE_BLE},
    {BLE_UUID_RUNNING_SPEED_AND_CADENCE, BLE_UUID_TYPE_BLE}
};

const char temperatureIcon[] = {
    0x00, 0x00, 0x3C, 0x7E, 0x66, 0x66, 0x3C, 0x18,
    0x18, 0x3C, 0x66, 0x66, 0x7E, 0x3C, 0x00, 0x00
};

unsigned char degreeSymbol[5] = {112,136,136,136,112};  // 8w x 5h
unsigned char snow[] = {0,0,0,0,0,16,16,40,40,16,17,0,2,128,1,0};  // 16w x 8h
unsigned char rain[] = {0,0,33,8,66,16,132,32};  // 16w x 4h
unsigned char thermometer[] = {8,20,212,20,20,220,28,28,220,28,62,127,127,127,62,28};  // 8w x 16h

/**@brief NUS UUID. */
static ble_uuid_t const m_nus_uuid =
{
    .uuid = BLE_UUID_NUS_SERVICE,
    .type = NUS_SERVICE_UUID_TYPE
};

void init_conn_handles(void)
{
    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        m_conn_handle_nus_c_arr[i] = BLE_CONN_HANDLE_INVALID;
    }
}
static ble_gap_scan_params_t m_scan_param =                 /**< Scan parameters requested for scanning and connection. */
{
    .active        = 0x01,
    .interval      = NRF_BLE_SCAN_SCAN_INTERVAL,
    .window        = NRF_BLE_SCAN_SCAN_WINDOW,
    .filter_policy = BLE_GAP_SCAN_FP_ACCEPT_ALL,
    .timeout       = NRF_BLE_SCAN_SCAN_DURATION,
    .scan_phys     = BLE_GAP_PHY_1MBPS,
    .extended      = true,
};


/**@brief Function for handling asserts in the SoftDevice.
 *
 * @details This function is called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and is not meant for the final product. You need to analyze
 *          how your product is supposed to react in case of assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num     Line number of the failing assert call.
 * @param[in] p_file_name  File name of the failing assert call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(0xDEADBEEF, line_num, p_file_name);
}


/**@brief Function for handling the Heart Rate Service Client
 *        Running Speed and Cadence Service Client.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void service_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for handling errors from the Connection Parameters module.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


static void scan_evt_handler(scan_evt_t const * p_scan_evt)
{
    ret_code_t err_code;
    ble_gap_evt_adv_report_t const * p_adv = 
                   p_scan_evt->params.filter_match.p_adv_report;
    ble_gap_scan_params_t    const * p_scan_param = 
                   p_scan_evt->p_scan_params;

    switch(p_scan_evt->scan_evt_id)
    {
        case NRF_BLE_SCAN_EVT_FILTER_MATCH:
        {
            // Initiate connection.
            err_code = sd_ble_gap_connect(&p_adv->peer_addr,
                                          p_scan_param,
                                          &m_scan.conn_params,
                                          APP_BLE_CONN_CFG_TAG);
            APP_ERROR_CHECK(err_code);
        } break;

        case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
        {
            err_code = p_scan_evt->params.connecting_err.err_code;
            APP_ERROR_CHECK(err_code);
        } break;

        case NRF_BLE_SCAN_EVT_CONNECTED:
        {
            ble_gap_evt_connected_t const * p_connected = p_scan_evt->params.connected.p_connected;
            NRF_LOG_INFO("Connected to target %02x%02x%02x%02x%02x%02x",
                         p_connected->peer_addr.addr[0],
                         p_connected->peer_addr.addr[1],
                         p_connected->peer_addr.addr[2],
                         p_connected->peer_addr.addr[3],
                         p_connected->peer_addr.addr[4],
                         p_connected->peer_addr.addr[5]);
        } break;


        default:
            break;
    }
}


/**@brief Function for initialization the scanning and setting the filters.
 */
static void scan_init(void)
{
    ret_code_t          err_code;
    nrf_ble_scan_init_t init_scan;

    memset(&init_scan, 0, sizeof(init_scan));

    init_scan.p_scan_param = &m_scan_param;
    //init_scan.connect_if_match = true;
    //init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;

    err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_scan_init : %d\n",err_code);

    //if (strlen(m_target_periph_name) != 0)
    //{
    //    err_code = nrf_ble_scan_filter_set(&m_scan, 
    //                                       SCAN_NAME_FILTER, 
    //                                       m_target_periph_name);
    //    NRF_LOG_INFO("SCAN_NAME_FILTER : %d\n",err_code);
    //    APP_ERROR_CHECK(err_code);
    //}

    //err_code = nrf_ble_scan_filter_set(&m_scan, 
    //                                   SCAN_UUID_FILTER, 
    //                                   &m_adv_uuids[HART_RATE_SERVICE_UUID_IDX]);
    //NRF_LOG_INFO("scan filter init HART_RATE_SERVICE_UUID_IDX : %d\n",err_code);
    //APP_ERROR_CHECK(err_code);

    //err_code = nrf_ble_scan_filter_set(&m_scan, 
    //                                   SCAN_UUID_FILTER, 
    //                                   &m_adv_uuids[RSCS_SERVICE_UUID_IDX]);
    //NRF_LOG_INFO("scan filter init RSCS_SERVICE_UUID_IDX : %d\n",err_code);
    //APP_ERROR_CHECK(err_code);

    //err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_UUID_FILTER, &m_nus_uuid);
    //NRF_LOG_INFO("scan filter init NUS : %d\n",err_code);
    //APP_ERROR_CHECK(err_code);

    //err_code = nrf_ble_scan_filters_enable(&m_scan, 
    //                                       NRF_BLE_SCAN_ALL_FILTER, 
    //                                       false);
    //NRF_LOG_INFO("nrf_ble_scan_filters_enable : %d\n",err_code);
    //APP_ERROR_CHECK(err_code);

}


/**@brief Function for initializing the scanning.
 */
static void scan_start(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_scan_start(&m_scan);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_scan_start : %d\n",err_code);
    NRF_LOG_INFO("SCAN START");
}


/**@brief Function for initializing the advertising and the scanning.
 */
static void adv_scan_start(void)
{
    ret_code_t err_code;

    //check if there are no flash operations in progress
    if (!nrf_fstorage_is_busy(NULL))
    {
        // Start scanning for peripherals and initiate connection to devices which
        // advertise Heart Rate or Running speed and cadence UUIDs.
        scan_start();

        // Turn on the LED to signal scanning.
        bsp_board_led_on(CENTRAL_SCANNING_LED);

        // Start advertising.
        err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
        APP_ERROR_CHECK(err_code);
    }
}


/**@brief Function for handling Peer Manager events.
 *
 * @param[in] p_evt  Peer Manager event.
 */
static void pm_evt_handler(pm_evt_t const * p_evt)
{
    pm_handler_on_pm_evt(p_evt);
    pm_handler_disconnect_on_sec_failure(p_evt);
    pm_handler_flash_clean(p_evt);

    switch (p_evt->evt_id)
    {
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            adv_scan_start();
            break;

        default:
            break;
    }
}


/**@brief Function for changing filter settings after establishing the connection.
 */
static void filter_settings_change(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_scan_all_filter_remove(&m_scan);
    APP_ERROR_CHECK(err_code);

    if (strlen(m_target_periph_name) != 0)
    {
        err_code = nrf_ble_scan_filter_set(&m_scan, 
                                           SCAN_NAME_FILTER, 
                                           m_target_periph_name);
        APP_ERROR_CHECK(err_code);
    }

    if ((m_conn_handle_hrs_c != BLE_CONN_HANDLE_INVALID) && 
        (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID))
    {
        err_code = nrf_ble_scan_filter_set(&m_scan, 
                                           SCAN_UUID_FILTER, 
                                           &m_adv_uuids[RSCS_SERVICE_UUID_IDX]);
    }

    if ((m_conn_handle_rscs_c != BLE_CONN_HANDLE_INVALID) && 
         m_conn_handle_hrs_c == BLE_CONN_HANDLE_INVALID)
    {
        err_code = nrf_ble_scan_filter_set(&m_scan, 
                                           SCAN_UUID_FILTER, 
                                           &m_adv_uuids[HART_RATE_SERVICE_UUID_IDX]);
    }

    APP_ERROR_CHECK(err_code);
}


/**@brief Handles events coming from the Heart Rate central module.
 */
static void hrs_c_evt_handler(ble_hrs_c_t * p_hrs_c, ble_hrs_c_evt_t * p_hrs_c_evt)
{
    switch (p_hrs_c_evt->evt_type)
    {
        case BLE_HRS_C_EVT_DISCOVERY_COMPLETE:
        {
            if (m_conn_handle_hrs_c == BLE_CONN_HANDLE_INVALID)
            {
                ret_code_t err_code;

                m_conn_handle_hrs_c = p_hrs_c_evt->conn_handle;
                NRF_LOG_INFO("HRS discovered on conn_handle 0x%x", m_conn_handle_hrs_c);

                filter_settings_change();

                err_code = ble_hrs_c_handles_assign(p_hrs_c,
                                                    m_conn_handle_hrs_c,
                                                    &p_hrs_c_evt->params.peer_db);
                APP_ERROR_CHECK(err_code);
                // Initiate bonding.
                err_code = pm_conn_secure(m_conn_handle_hrs_c, false);
                if (err_code != NRF_ERROR_BUSY)
                {
                    APP_ERROR_CHECK(err_code);
                }

                // Heart rate service discovered. Enable notification of Heart Rate Measurement.
                err_code = ble_hrs_c_hrm_notif_enable(p_hrs_c);
                APP_ERROR_CHECK(err_code);
            }
        } break; // BLE_HRS_C_EVT_DISCOVERY_COMPLETE

        case BLE_HRS_C_EVT_HRM_NOTIFICATION:
        {
            ret_code_t err_code;

            NRF_LOG_INFO("Heart Rate = %d", p_hrs_c_evt->params.hrm.hr_value);

            err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, p_hrs_c_evt->params.hrm.hr_value);
            if ((err_code != NRF_SUCCESS) &&
                (err_code != NRF_ERROR_INVALID_STATE) &&
                (err_code != NRF_ERROR_RESOURCES) &&
                (err_code != NRF_ERROR_BUSY) &&
                (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
                )
            {
                APP_ERROR_HANDLER(err_code);
            }
        } break; // BLE_HRS_C_EVT_HRM_NOTIFICATION

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Handles events coming from  Running Speed and Cadence central module.
 */
static void rscs_c_evt_handler(ble_rscs_c_t * p_rscs_c, ble_rscs_c_evt_t * p_rscs_c_evt)
{
    switch (p_rscs_c_evt->evt_type)
    {
        case BLE_RSCS_C_EVT_DISCOVERY_COMPLETE:
        {
            if (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID)
            {
                ret_code_t err_code;

                m_conn_handle_rscs_c = p_rscs_c_evt->conn_handle;
                NRF_LOG_INFO("Running Speed and Cadence service discovered on conn_handle 0x%x",
                             m_conn_handle_rscs_c);

                filter_settings_change();

                err_code = ble_rscs_c_handles_assign(p_rscs_c,
                                                    m_conn_handle_rscs_c,
                                                    &p_rscs_c_evt->params.rscs_db);
                APP_ERROR_CHECK(err_code);

                // Initiate bonding.
                err_code = pm_conn_secure(m_conn_handle_rscs_c, false);
                if (err_code != NRF_ERROR_BUSY)
                {
                    APP_ERROR_CHECK(err_code);
                }

                // Running Speed Cadence Service discovered. Enable notifications.
                err_code = ble_rscs_c_rsc_notif_enable(p_rscs_c);
                APP_ERROR_CHECK(err_code);
            }
        } break; // BLE_RSCS_C_EVT_DISCOVERY_COMPLETE:

        case BLE_RSCS_C_EVT_RSC_NOTIFICATION:
        {
            ret_code_t      err_code;
            ble_rscs_meas_t rscs_measurment;

            NRF_LOG_INFO("Speed      = %d", p_rscs_c_evt->params.rsc.inst_speed);

            rscs_measurment.is_running                  = p_rscs_c_evt->params.rsc.is_running;
            rscs_measurment.is_inst_stride_len_present  = p_rscs_c_evt->params.rsc.is_inst_stride_len_present;
            rscs_measurment.is_total_distance_present   = p_rscs_c_evt->params.rsc.is_total_distance_present;

            rscs_measurment.inst_stride_length = p_rscs_c_evt->params.rsc.inst_stride_length;
            rscs_measurment.inst_cadence       = p_rscs_c_evt->params.rsc.inst_cadence;
            rscs_measurment.inst_speed         = p_rscs_c_evt->params.rsc.inst_speed;
            rscs_measurment.total_distance     = p_rscs_c_evt->params.rsc.total_distance;

            err_code = ble_rscs_measurement_send(&m_rscs, &rscs_measurment);
            if ((err_code != NRF_SUCCESS) &&
                (err_code != NRF_ERROR_INVALID_STATE) &&
                (err_code != NRF_ERROR_RESOURCES) &&
                (err_code != NRF_ERROR_BUSY) &&
                (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
                )
            {
                APP_ERROR_HANDLER(err_code);
            }
        } break; // BLE_RSCS_C_EVT_RSC_NOTIFICATION

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for assigning new connection handle to available instance of QWR module.
 *
 * @param[in] conn_handle New connection handle.
 */
static void multi_qwr_conn_handle_assign(uint16_t conn_handle)
{
    for (uint32_t i = 0; i < NRF_SDH_BLE_TOTAL_LINK_COUNT; i++)
    {
        if (m_qwr[i].conn_handle == BLE_CONN_HANDLE_INVALID)
        {
            ret_code_t err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr[i], conn_handle);
            APP_ERROR_CHECK(err_code);
            break;
        }
    }
}



void temperature_humidty(uint8_t temp1, uint8_t temp2, uint8_t humidity1, uint8_t humidity2)
{
   // NRF_LOG_INFO("Temp1: %02X", temp1);
   // NRF_LOG_INFO("Temp2: %02X", temp2);
   // NRF_LOG_INFO("Humidity1: %02X", humidity1);
   // NRF_LOG_INFO("Humidity2: %02X", humidity2);

    char ch_humidity[24];
    char temperature[24];
    memset(ch_humidity, 0, sizeof(ch_humidity));
    memset(temperature, 0, sizeof(temperature));

    int temp = (temp2) + (temp1 << 8);
    int calcTempScaled = (temp * 100) / 256;
    sprintf(temperature, "%d.%02d C", calcTempScaled / 100, calcTempScaled % 100);

    int hum = (humidity2) + (humidity1 << 8);
    int calcHumScaled = (hum * 100) / 256;
    sprintf(ch_humidity, "%d.%02d", calcHumScaled / 100, calcHumScaled % 100);

   // NRF_LOG_INFO("Temperature: %s \t Humidity: %s\n", temperature, ch_humidity);
    nrf_delay_ms(200); 

    Display_Clear();
    Display_Goto(3,10);
    Display_Puts(temperature);
    Display_Goto(5,10);
    Display_Puts(ch_humidity);


	
}

void panic_button_pressed(uint8_t const *mac_address)
{

 char alert_message[50]; // Buffer to hold the concatenated message
 char mac_string[18];    // Buffer to hold the MAC address as a string

 Display_Clear();
 Display_Goto(3,10);
 Display_Puts("ALERT !!");
 NRF_LOG_INFO("PANIC BUTTON PRESSED \n");

 snprintf(mac_string, sizeof(mac_string), "%02X:%02X:%02X:%02X:%02X:%02X",
          mac_address[5],
          mac_address[4],
          mac_address[3],
          mac_address[2],
          mac_address[1],
          mac_address[0]);

  snprintf(alert_message, sizeof(alert_message), "DATA:%s-ALERT", mac_string);
  NRF_LOG_INFO("Device Address: %s", mac_string);
  NRF_LOG_INFO("Message to send: %s", alert_message);

  uint16_t length = strlen(alert_message);
  ret_code_t ret_val = ble_nus_data_send(&m_nus,alert_message, &length, m_conn_handle);
  if (ret_val != NRF_SUCCESS)
  {
     NRF_LOG_ERROR("Failed to send data over BLE. Error code: 0x%x", ret_val);
  }

}
/**@brief   Function for handling BLE events from the central application.
 *
 * @details This function parses scanning reports and initiates a connection to peripherals when a
 *          target UUID is found. It updates the status of LEDs used to report the central application
 *          activity.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 */
static void on_ble_central_evt(ble_evt_t const * p_ble_evt)
{
    ret_code_t            err_code;
    ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;

    switch (p_ble_evt->header.evt_id)
    {
        // Upon connection, check which peripheral is connected (HR or RSC), initiate DB
        // discovery, update LEDs status, and resume scanning, if necessary.
        case BLE_GAP_EVT_CONNECTED:
        {
            NRF_LOG_INFO("Central connected");
            // If no Heart Rate sensor or RSC sensor is currently connected, try to find them on this peripheral.
            // Attempt to find HRS, RSC, or NUS on the connected peripheral.
            for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
            {
                if (   (m_conn_handle_hrs_c  == BLE_CONN_HANDLE_INVALID)
                    || (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID)
                    || (m_conn_handle_nus_c_arr[i] == BLE_CONN_HANDLE_INVALID)) // Check for free slot in NUS connections.
                {
                    NRF_LOG_INFO("Attempt to find HRS, RSC, or NUS conn_handle 0x%x", p_gap_evt->conn_handle);

                    err_code = ble_db_discovery_start(&m_db_discovery[i], p_gap_evt->conn_handle);
                    if (err_code != NRF_ERROR_BUSY)
                    {
                        APP_ERROR_CHECK(err_code);
                        break;
                    }
                }
            }

            // Assign connection handle to NUS Client
            for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
            {
                if (m_conn_handle_nus_c_arr[i] == BLE_CONN_HANDLE_INVALID)
                {
                    err_code = ble_nus_c_handles_assign(&m_ble_nus_c_arr[i], p_gap_evt->conn_handle, NULL);
                    APP_ERROR_CHECK(err_code);
                    m_conn_handle_nus_c_arr[i] = p_gap_evt->conn_handle;
                    NRF_LOG_INFO("NUS client assigned to conn_handle 0x%x (index: %d)", p_gap_evt->conn_handle, i);
                    break;
                }
            }
            // Assign connection handle to NUS Client
            //err_code = ble_nus_c_handles_assign(&m_ble_nus_c, p_ble_evt->evt.gap_evt.conn_handle, NULL);  //added nus handle assigning 
            //APP_ERROR_CHECK(err_code);

            // Assign connection handle to the QWR module.
            multi_qwr_conn_handle_assign(p_gap_evt->conn_handle);

            // Update LEDs status, and check whether to look for more peripherals to connect to.
            bsp_board_led_on(CENTRAL_CONNECTED_LED);
            if (ble_conn_state_central_conn_count() == NRF_SDH_BLE_CENTRAL_LINK_COUNT)
            {
                bsp_board_led_off(CENTRAL_SCANNING_LED);
            }
            else
            {
                // Resume scanning.
                bsp_board_led_on(CENTRAL_SCANNING_LED);
                scan_start();
            }
        } break; // BLE_GAP_EVT_CONNECTED

        case BLE_GAP_EVT_ADV_REPORT:
        {
            //NRF_LOG_INFO("BLE_GAP_ADV_REPORT \n");
            ble_gap_evt_adv_report_t const * p_adv_report = &p_gap_evt->params.adv_report;
            if (((p_adv_report->peer_addr.addr[5] == 0xBC) && 
                 (p_adv_report->peer_addr.addr[4] == 0x57) && 
                 (p_adv_report->peer_addr.addr[3] == 0x29) && 
                 (p_adv_report->peer_addr.addr[2] == 0x01) && 
                 (p_adv_report->peer_addr.addr[1] == 0xAA) && 
                 (p_adv_report->peer_addr.addr[0] == 0xBD)) || 
                 ((p_adv_report->peer_addr.addr[5] == 0xBC) && 
                 (p_adv_report->peer_addr.addr[4] == 0x57) && 
                 (p_adv_report->peer_addr.addr[3] == 0x29) && 
                 (p_adv_report->peer_addr.addr[2] == 0x00) && 
                 (p_adv_report->peer_addr.addr[1] == 0x93) && 
                 (p_adv_report->peer_addr.addr[0] == 0xDA))) 
                 {
                     
                     NRF_LOG_INFO("Device Address: %02X:%02X:%02X:%02X:%02X:%02X\n",
                         p_adv_report->peer_addr.addr[5],
                         p_adv_report->peer_addr.addr[4],
                         p_adv_report->peer_addr.addr[3],
                         p_adv_report->peer_addr.addr[2],
                         p_adv_report->peer_addr.addr[1],
                         p_adv_report->peer_addr.addr[0]);

                     //NRF_LOG_HEXDUMP_INFO(p_adv_report->data.p_data, p_adv_report->data.len);
                    // NRF_LOG_INFO("Advertising Data (Length: %d): \n", p_adv_report->data.len);
                    // for (uint32_t i = 0; i < p_adv_report->data.len; i++)
                     // {
                      //  NRF_LOG_INFO("%02X \t", p_adv_report->data.p_data[i]);
                     // }
                     //NRF_LOG_INFO("\n");
                     nrf_delay_ms(100);
                     if((p_adv_report->data.p_data[3]==0x03)&&(p_adv_report->data.p_data[4]==0x03)
			&&(p_adv_report->data.p_data[5]==0xAA)&&(p_adv_report->data.p_data[6]==0xFE))
                        {
                              nrf_delay_ms(100);
                             if((p_adv_report->data.p_data[11]==0x20)
				||(p_adv_report->data.p_data[11]==0x21))
				{
				  //calculate temperature 
                                  nrf_delay_ms(100);
                                  //NRF_LOG_INFO("enter in temperature humidity\n");
				  temperature_humidty(p_adv_report->data.p_data[16],p_adv_report->data.p_data[17],
						      p_adv_report->data.p_data[18],p_adv_report->data.p_data[19]);
				}
                                else if (p_adv_report->data.p_data[11]==0x22)
				{
                                   nrf_delay_ms(100);
                                  // NRF_LOG_INFO("enter in panic button pressed \n");
				   panic_button_pressed(p_adv_report->peer_addr.addr);
						    
				}
                        }


                 }

        }
        break; 

        // Upon disconnection, reset the connection handle of the peer that disconnected,
        // update the LEDs status and start scanning again.
        case BLE_GAP_EVT_DISCONNECTED:
        {

         NRF_LOG_INFO("Device disconnected, conn_handle: 0x%x, reason: 0x%x",
                         p_gap_evt->conn_handle,
                         p_gap_evt->params.disconnected.reason);

            if (p_gap_evt->conn_handle == m_conn_handle_hrs_c)
            {
                NRF_LOG_INFO("HRS central disconnected (reason: %d)",
                             p_gap_evt->params.disconnected.reason);

                m_conn_handle_hrs_c = BLE_CONN_HANDLE_INVALID;
                
                err_code = nrf_ble_scan_filter_set(&m_scan, 
                                                   SCAN_UUID_FILTER, 
                                                   &m_adv_uuids[HART_RATE_SERVICE_UUID_IDX]);
                NRF_LOG_INFO("HRS service disconnected.");
                APP_ERROR_CHECK(err_code);
            }

            if (p_gap_evt->conn_handle == m_conn_handle_rscs_c)
            {
                NRF_LOG_INFO("RSC central disconnected (reason: %d)",
                             p_gap_evt->params.disconnected.reason);

                m_conn_handle_rscs_c = BLE_CONN_HANDLE_INVALID;

                err_code = nrf_ble_scan_filter_set(&m_scan, 
                                                   SCAN_UUID_FILTER, 
                                                   &m_adv_uuids[RSCS_SERVICE_UUID_IDX]);
                                              
                NRF_LOG_INFO("RSCS service disconnected.");
                APP_ERROR_CHECK(err_code);
            }


            //if (p_gap_evt->conn_handle == m_conn_handle_nus_c)
            //{
            //    m_conn_handle_nus_c = BLE_CONN_HANDLE_INVALID;
            //    NRF_LOG_INFO("NUS service disconnected.");
            //}

            for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
            {
                if (p_gap_evt->conn_handle == m_conn_handle_nus_c_arr[i])
                {
                    m_conn_handle_nus_c_arr[i] = BLE_CONN_HANDLE_INVALID;
                    NRF_LOG_INFO("NUS service disconnected (index: %d)", i);
                    break;
                }
            }


            //if (   (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID)
            //    || (m_conn_handle_hrs_c  == BLE_CONN_HANDLE_INVALID)||(m_conn_handle_nus_c==BLE_CONN_HANDLE_INVALID)) //added nus connection handle checking
            //{
            //    // Start scanning.
            //    scan_start();

            //    // Update LEDs status.
            //    bsp_board_led_on(CENTRAL_SCANNING_LED);
            //}

            // Check if any connection handle is invalid and restart scanning if needed
    bool any_invalid_handle = (m_conn_handle_hrs_c == BLE_CONN_HANDLE_INVALID) ||
                              (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID);
    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        if (m_conn_handle_nus_c_arr[i] == BLE_CONN_HANDLE_INVALID)
        {
            any_invalid_handle = true;
            break;
        }
    }

    if (any_invalid_handle)
    {
        // Restart scanning if there is any invalid connection handle
        scan_start();

        // Update LEDs to indicate scanning
        bsp_board_led_on(CENTRAL_SCANNING_LED);
    }

            if (ble_conn_state_central_conn_count() == 0)
            {
                bsp_board_led_off(CENTRAL_CONNECTED_LED);
            }
        } break; // BLE_GAP_EVT_DISCONNECTED

        case BLE_GAP_EVT_TIMEOUT:
        {
            // No timeout for scanning is specified, so only connection attemps can timeout.
            if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN)
            {
                NRF_LOG_INFO("Connection Request timed out.");
            }
        } break;

        case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
        {
            // Accept parameters requested by peer.
            err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
                                        &p_gap_evt->params.conn_param_update_request.conn_params);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_DEBUG("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_DEBUG("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief   Function for handling BLE events from peripheral applications.
 * @details Updates the status LEDs used to report the activity of the peripheral applications.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 */
static void on_ble_peripheral_evt(ble_evt_t const * p_ble_evt)
{
    ret_code_t            err_code;
    ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Peripheral connected");
            bsp_board_led_off(PERIPHERAL_ADVERTISING_LED);
            bsp_board_led_on(PERIPHERAL_CONNECTED_LED);

            // Assign connection handle to the QWR module.
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            multi_qwr_conn_handle_assign(p_ble_evt->evt.gap_evt.conn_handle);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Peripheral disconnected. conn_handle: 0x%x, reason: 0x%x",
                         p_gap_evt->conn_handle,
                         p_gap_evt->params.disconnected.reason);

            bsp_board_led_off(PERIPHERAL_CONNECTED_LED);
            break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_DEBUG("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_DEBUG("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for handling advertising events.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
        {
            NRF_LOG_INFO("Fast advertising.");
            bsp_board_led_on(PERIPHERAL_ADVERTISING_LED);
        } break;

        case BLE_ADV_EVT_IDLE:
        {
            ret_code_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
            NRF_LOG_INFO("BLE ADV EVT IDLE\n");
            APP_ERROR_CHECK(err_code);
        } break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for checking whether a bluetooth stack event is an advertising timeout.
 *
 * @param[in] p_ble_evt Bluetooth stack event.
 */
static bool ble_evt_is_advertising_timeout(ble_evt_t const * p_ble_evt)
{
    return (p_ble_evt->header.evt_id == BLE_GAP_EVT_ADV_SET_TERMINATED);
}


/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    uint16_t conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
    uint16_t role        = ble_conn_state_role(conn_handle);
    //NRF_LOG_INFO("enter in ble evt handler \n ");
    // Based on the role this device plays in the connection, dispatch to the right handler.
    if (role == BLE_GAP_ROLE_PERIPH || ble_evt_is_advertising_timeout(p_ble_evt))
    {
        //NRF_LOG_INFO("ble gap role peripherel  \n ");
        ble_hrs_on_ble_evt(p_ble_evt, &m_hrs);
        ble_rscs_on_ble_evt(p_ble_evt, &m_rscs);
        ble_nus_on_ble_evt(p_ble_evt, &m_nus);  // Adding this line for NUS peripheral handling
        on_ble_peripheral_evt(p_ble_evt);
    }
    else if ((role == BLE_GAP_ROLE_CENTRAL) || (p_ble_evt->header.evt_id == BLE_GAP_EVT_ADV_REPORT))
    {
        //NRF_LOG_INFO("ble gap role central   \n ");
       // ble_hrs_c_on_ble_evt(p_ble_evt, &m_hrs_c);
      //  ble_rscs_c_on_ble_evt(p_ble_evt, &m_rscs_c);
      //  for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
     //  {
     //    ble_nus_c_on_ble_evt(p_ble_evt, &m_ble_nus_c_arr[i]);
     //   }
        //ble_nus_c_on_ble_evt(p_ble_evt,&m_ble_nus_c);   // need to check this operation is neccesssary 
        on_ble_central_evt(p_ble_evt);
    }
}

/**@brief Function for handling the Nordic UART Service Client errors.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nus_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}

static void ble_nus_chars_received_log_print(uint8_t * p_data, uint16_t data_len)
{

   NRF_LOG_INFO("ble_nus_chars_received_log_print\n");
   ret_code_t ret_val;
   char received_str[64];
   memset(received_str,0,sizeof(received_str));
   NRF_LOG_DEBUG("Receiving data.");
   NRF_LOG_HEXDUMP_DEBUG(p_data, data_len);
	
   for (uint32_t i = 0; i < data_len; i++)
    {
	 received_str[i]=p_data[i];
    }
	NRF_LOG_INFO("received_str_from_peripherel  : %s\n",received_str);
        uint16_t length=strlen(received_str);
        ret_val = ble_nus_data_send(&m_nus,received_str, &length,m_conn_handle);


}


static void ble_nus_c_evt_handler(ble_nus_c_t * p_ble_nus_c, ble_nus_c_evt_t const * p_ble_nus_evt)
{

 ret_code_t err_code;
 uint8_t instance_index = p_ble_nus_c - m_ble_nus_c_arr; // Calculate the instance index
 NRF_LOG_INFO("current instance index %d\n", instance_index);
 switch (p_ble_nus_evt->evt_type)
 {
  
     case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
          NRF_LOG_INFO("Discovery complete ble_nus_c_evt_handler");
          err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
          APP_ERROR_CHECK(err_code);

          err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
          APP_ERROR_CHECK(err_code);
          NRF_LOG_INFO("Connected to device with Nordic UART Service.");

          m_conn_handle_nus_c_arr[instance_index] = p_ble_nus_evt->conn_handle;

          break;

     case BLE_NUS_C_EVT_NUS_TX_EVT:
          
          ble_nus_chars_received_log_print(p_ble_nus_evt->p_data, p_ble_nus_evt->data_len);
          break;

     case BLE_NUS_C_EVT_DISCONNECTED:
          NRF_LOG_INFO("Disconnected from instance %d", instance_index);
          m_conn_handle_nus_c_arr[instance_index] = BLE_CONN_HANDLE_INVALID;
          //NRF_LOG_INFO("Disconnected");
          scan_start();
          break;


 }
}
/**@brief Function for initializing the Nordic UART Service (NUS) client. */
static void nus_c_init(void)
{
    ret_code_t       err_code;
    ble_nus_c_init_t init;

    init.evt_handler   = ble_nus_c_evt_handler;
    init.error_handler = nus_error_handler;
    init.p_gatt_queue  = &m_ble_gatt_queue;

    //err_code = ble_nus_c_init(&m_ble_nus_c, &init);
    //NRF_LOG_INFO("ble_nus_c_init : %d\n",err_code);
    //APP_ERROR_CHECK(err_code);

    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        err_code = ble_nus_c_init(&m_ble_nus_c_arr[i], &init);
        NRF_LOG_INFO("ble_nus_c_init for instance %d: %d", i, err_code);
        APP_ERROR_CHECK(err_code);
    }
}

/**@brief Heart Rate Collector initialization.
 */
static void hrs_c_init(void)
{
    ret_code_t       err_code;
    ble_hrs_c_init_t hrs_c_init_obj;

    hrs_c_init_obj.evt_handler   = hrs_c_evt_handler;
    hrs_c_init_obj.error_handler = service_error_handler;
    hrs_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

    err_code = ble_hrs_c_init(&m_hrs_c, &hrs_c_init_obj);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_hrs_c_init : %d\n",err_code);
}


/**@brief RSC collector initialization.
 */
static void rscs_c_init(void)
{
    ret_code_t        err_code;
    ble_rscs_c_init_t rscs_c_init_obj;

    rscs_c_init_obj.evt_handler   = rscs_c_evt_handler;
    rscs_c_init_obj.error_handler = service_error_handler;
    rscs_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

    err_code = ble_rscs_c_init(&m_rscs_c, &rscs_c_init_obj);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_rscs_c_init : %d\n",err_code);
}


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupts.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_sdh_enable_request : %d\n",err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_sdh_ble_default_cfg_set : %d\n",err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_sdh_ble_enable : %d\n",err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    NRF_LOG_INFO(" after nrf sdh ble observer \n");
}


/**@brief Function for initializing the Peer Manager.
 */
static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t err_code;

    err_code = pm_init();
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_init : %d\n",err_code);
    

    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

    // Security parameters to be used for all security procedures.
    sec_param.bond           = SEC_PARAM_BOND;
    sec_param.mitm           = SEC_PARAM_MITM;
    sec_param.lesc           = SEC_PARAM_LESC;
    sec_param.keypress       = SEC_PARAM_KEYPRESS;
    sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
    sec_param.oob            = SEC_PARAM_OOB;
    sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
    sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
    sec_param.kdist_own.enc  = 1;
    sec_param.kdist_own.id   = 1;
    sec_param.kdist_peer.enc = 1;
    sec_param.kdist_peer.id  = 1;

    err_code = pm_sec_params_set(&sec_param);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_sec_params_set : %d\n",err_code);

    err_code = pm_register(pm_evt_handler);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_register : %d\n",err_code);
}


/**@brief Clear bond information from persistent storage.
 */
static void delete_bonds(void)
{
    ret_code_t err_code;

    NRF_LOG_INFO("Erase bonds!");

    err_code = pm_peers_delete();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing buttons and LEDs.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to
 *                            wake the application up.
 */
static void buttons_leds_init(bool * p_erase_bonds)
{
    ret_code_t err_code;
    bsp_event_t startup_event;

    err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, NULL);
    APP_ERROR_CHECK(err_code);

    err_code = bsp_btn_ble_init(NULL, &startup_event);
    APP_ERROR_CHECK(err_code);

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


/**@brief Function for initializing the GAP.
 *
 * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of the
 *          device, including the device name, appearance, and the preferred connection parameters.
 */
static void gap_params_init(void)
{
    ret_code_t              err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *)DEVICE_NAME,
                                          strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    memset(&gap_conn_params, 0, sizeof(gap_conn_params));

    gap_conn_params.min_conn_interval = m_scan.conn_params.min_conn_interval;
    gap_conn_params.max_conn_interval = m_scan.conn_params.max_conn_interval;
    gap_conn_params.slave_latency     = m_scan.conn_params.slave_latency;
    gap_conn_params.conn_sup_timeout  = m_scan.conn_params.conn_sup_timeout;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling events from the GATT library. */
void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
{
    if (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED)
    {
        NRF_LOG_INFO("ATT MTU exchange completed.");

        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        NRF_LOG_INFO("Ble NUS max data length set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
}

/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void)
{
    ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_gatt_init : %d\n",err_code);
    // Set the ATT MTU size for central role
    err_code = nrf_ble_gatt_att_mtu_central_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_gatt_att_mtu_central_set : %d\n",err_code);
    // Set the ATT MTU size for peripheral role
    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_gatt_att_mtu_periph_set : %d\n",err_code);


}


/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    ret_code_t             err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_CONN_HANDLE_INVALID; // Start upon connection.
    cp_init.disconnect_on_fail             = true;
    cp_init.evt_handler                    = NULL;  // Ignore events.
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling database discovery events.
 *
 * @details This function is a callback function to handle events from the database discovery module.
 *          Depending on the UUIDs that are discovered, this function forwards the events
 *          to their respective services.
 *
 * @param[in] p_event  Pointer to the database discovery event.
 */
static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
{
    ble_db_discovery_t const * p_db = (ble_db_discovery_t *)p_evt->params.p_db_instance;

    ble_hrs_on_db_disc_evt(&m_hrs_c, p_evt);
    ble_rscs_on_db_disc_evt(&m_rscs_c, p_evt);
   // ble_nus_c_on_db_disc_evt(&m_ble_nus_c, p_evt);     // nus central db disc evt handler . 

   // Iterate over the NUS client array to find the appropriate instance.
    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        if (p_evt->conn_handle == m_conn_handle_nus_c_arr[i])
        {
            ble_nus_c_on_db_disc_evt(&m_ble_nus_c_arr[i], p_evt);
            break;
        }
    }

    if (p_evt->evt_type == BLE_DB_DISCOVERY_AVAILABLE) {
        NRF_LOG_INFO("DB Discovery instance %p available on conn handle: %d",
                     p_db,
                     p_evt->conn_handle);
        NRF_LOG_INFO("Found %d services on conn_handle: %d",
                     p_db->srv_count,
                     p_evt->conn_handle);
    }
}


/**
 * @brief Database discovery initialization.
 */
static void db_discovery_init(void)
{
    ble_db_discovery_init_t db_init;

    memset(&db_init, 0, sizeof(ble_db_discovery_init_t));

    db_init.evt_handler  = db_disc_handler;
    db_init.p_gatt_queue = &m_ble_gatt_queue;

    ret_code_t err_code = ble_db_discovery_init(&db_init);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_db_discovery_init :%d\n",err_code);
}


/**@brief Function for handling Queued Write module errors.
 *
 * @details A pointer to this function is passed to each service that may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code that contains information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}
void string_conversion(char*data)
{

  char converted_array[24];
  memset(converted_array,0,sizeof(converted_array));
  NRF_LOG_INFO("device on mac id : %s\n",data);
  sprintf(converted_array,"mac-%s",data);
  NRF_LOG_INFO("converted_array: %s\n",converted_array);
  nrf_delay_ms(100);

  

}


void processdata (char *received_data)
{

    char mac_string[18];  // Increased buffer size to 18
    char mac_address[18]; // Enough space for a MAC address (XX:XX:XX:XX:XX:XX) + null terminator
    char message[47]; 
    memset(mac_string, 0, sizeof(mac_string));

    ble_gap_addr_t addr;
    uint32_t err_code = sd_ble_gap_addr_get(&addr);
    APP_ERROR_CHECK(err_code);

    // Print the MAC address directly to the log
    NRF_LOG_INFO("OWN_MAC_ID :%02X:%02X:%02X:%02X:%02X:%02X",
                 addr.addr[5], addr.addr[4], addr.addr[3],
                 addr.addr[2], addr.addr[1], addr.addr[0]);

    NRF_LOG_INFO("DATA : %s\n", received_data);
    snprintf(mac_string,sizeof(mac_string), "%02X:%02X:%02X:%02X:%02X:%02X",addr.addr[5],addr.addr[4],addr.addr[3],addr.addr[2],addr.addr[1],addr.addr[0]);
    for (int i = 0; i < sizeof(mac_string); i++) 
    {
        NRF_LOG_INFO("Byte %d: 0x%02X", i, mac_string[i]);
    }
    //string_conversion(mac_string);
    nrf_delay_ms(100);
    Display_Clear();
    Display_Goto(2,10);
    Display_Puts(mac_string);
    nrf_delay_ms(100);
    NRF_LOG_INFO(mac_string);
    nrf_delay_ms(100);

     char *comma_pos = strchr(received_data, ',');
     if (comma_pos != NULL) 
    { // Check if a comma was found
        // Calculate the length of the MAC address
        int mac_len = comma_pos - received_data;

        // Copy the MAC address
        strncpy(mac_address, received_data, mac_len);
        mac_address[mac_len] = '\0'; // Null-terminate the string

        //Copy the message after the comma.
        strcpy(message,comma_pos + 1);

        NRF_LOG_INFO("MAC Address: %s\n", mac_address);
        NRF_LOG_INFO("Message: %s\n", message);
        Display_Goto(3,10);
        Display_Puts(mac_address);
        Display_Goto(4,10);
        Display_Puts(message);

        if (strcmp(mac_string, mac_address) == 0)
        {
            NRF_LOG_INFO("mac_string and mac_address MATCH!");
            nrf_delay_ms(1000);
             Display_Clear();
             Display_Goto(1,10);
             Display_Puts("NURSE ON THE WAY");
        }
        else
        {
            NRF_LOG_INFO("mac_string and mac_address DO NOT MATCH!");
        }

    } 
     else
    {
        NRF_LOG_INFO("Comma not found in the string.\n");
    }
}

static void nus_data_handler(ble_nus_evt_t * p_evt)
{

  memset(Bledatabuff,0,sizeof(Bledatabuff));
  uint16_t data_len=0;
  ret_code_t ret_val;
  // write the code for nus data handling .
   if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
        NRF_LOG_DEBUG("Received data from BLE NUS.");

        // Copy received data to Bledatabuff array
        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
        {
            Bledatabuff[i] = p_evt->params.rx_data.p_data[i];
        }

        NRF_LOG_INFO("RECEIVED DATA : %s\n",Bledatabuff);
        processdata(Bledatabuff);
      //  for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
       // {
       // if (m_conn_handle_nus_c_arr[i] != BLE_CONN_HANDLE_INVALID)
       // {
         //data_len=strlen(Bledatabuff);
         //NRF_LOG_INFO("RECIVED ble data ");
         //ret_code_t err_code = ble_nus_c_string_send(&m_ble_nus_c_arr[i],Bledatabuff,data_len);
         // if (err_code != NRF_SUCCESS)
         //       {
         //           NRF_LOG_ERROR("Failed to forward data to instance %d: %d", i, err_code);
         //       }
        // }

        //}
    }
   // NRF_LOG_INFO(" Received ble data : %s\n",Bledatabuff );
   // data_len=strlen(Bledatabuff);
   // ret_val=ble_nus_c_string_send(&m_ble_nus_c, Bledatabuff, data_len);
   // NRF_LOG_INFO("ble_nus_c_string_send : %d\n",ret_val);


}
/**@brief Function for initializing services that are be used by the application.
 *
 * @details Initialize the Heart Rate, Battery and Device Information services.
 */
static void services_init(void)
{
    ret_code_t         err_code;
    ble_hrs_init_t     hrs_init;
    ble_rscs_init_t    rscs_init;
    ble_nus_init_t     nus_init;
    nrf_ble_qwr_init_t qwr_init = {0};
    uint8_t            body_sensor_location;

   

    // Initialize Queued Write module instances.
    qwr_init.error_handler = nrf_qwr_error_handler;

    for (uint32_t i = 0; i < NRF_SDH_BLE_TOTAL_LINK_COUNT; i++)
    {
        err_code = nrf_ble_qwr_init(&m_qwr[i], &qwr_init);
        APP_ERROR_CHECK(err_code);
        NRF_LOG_INFO("nrf_ble_qwr_init : %d\n",err_code);
    }

    // Initialize the Heart Rate Service.
    body_sensor_location = BLE_HRS_BODY_SENSOR_LOCATION_FINGER;

    memset(&hrs_init, 0, sizeof(hrs_init));

    hrs_init.evt_handler                 = NULL;
    hrs_init.is_sensor_contact_supported = true;
    hrs_init.p_body_sensor_location      = &body_sensor_location;

    // Here the sec level for the Heart Rate Service can be changed or increased.
    hrs_init.hrm_cccd_wr_sec = SEC_OPEN;
    hrs_init.bsl_rd_sec      = SEC_OPEN;

    err_code = ble_hrs_init(&m_hrs, &hrs_init);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_hrs_init : %d\n",err_code);

    // Initialize the Running Speed and Cadence Service.
    memset(&rscs_init, 0, sizeof(rscs_init));

    rscs_init.evt_handler = NULL;
    rscs_init.feature     = BLE_RSCS_FEATURE_INSTANT_STRIDE_LEN_BIT |
                            BLE_RSCS_FEATURE_WALKING_OR_RUNNING_STATUS_BIT;

    // Here the sec level for the Running Speed and Cadence Service can be changed or increased.
    rscs_init.rsc_feature_rd_sec   = SEC_OPEN;
    rscs_init.rsc_meas_cccd_wr_sec = SEC_OPEN;

    err_code = ble_rscs_init(&m_rscs, &rscs_init);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_rscs_init : %d\n ",err_code);

    memset(&nus_init, 0, sizeof(nus_init));     
    nus_init.data_handler = nus_data_handler;    //intialisation parts for the nus 
    err_code = ble_nus_init(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_INFO(" ble_nus_init : %d\n",err_code);

}


/**@brief Function for initializing the advertising functionality.
 */
static void advertising_init(void)
{
    ret_code_t             err_code;
    ble_advertising_init_t init;

    memset(&init, 0, sizeof(init));

    init.advdata.name_type               = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance      = true;
    init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
    init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.advdata.uuids_complete.p_uuids  = m_adv_uuids;

    init.config.ble_adv_fast_enabled  = true;
    init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;

    init.evt_handler = on_adv_evt;

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@brief Function for initializing logging.
 */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop). If there is no pending log operation,
          then sleeps until the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


/**@brief Function for initializing the timer.
 */
static void timer_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the application main entry.
 */
int main(void)
{
    bool erase_bonds;

    // Initialize.       //nurseresponse 
    log_init();
    timer_init();
    buttons_leds_init(&erase_bonds);
   // button_init();
    nrf_gpio_pin_clear(BUZZ_PIN);
    nrf_gpio_cfg_input(POWER_STS,NRF_GPIO_PIN_PULLUP); //Configure input pins
    nrf_gpio_cfg_input(KEY1,NRF_GPIO_PIN_PULLUP);
    nrf_gpio_cfg_input(KEY2,NRF_GPIO_PIN_PULLUP);
    nrf_gpio_pin_dir_set(BATTERY_ON,NRF_GPIO_PIN_DIR_OUTPUT);
    nrf_gpio_pin_set(BATTERY_ON);//Initial value of BATTERY_ON is 
    nrf_gpio_pin_write(BATTERY_ON,CLEAR);
    nrf_delay_ms(1000);
    power_management_init();
    
    ssd1306_init_i2c(23,24);
    Display_Init();
    //Display_EnableInversion();
    Display_Clear();
    DrawBox_oled();
    Display_SetBrightness(254);
    Display_big_font("SOFTLAND",3,10,3);
    nrf_delay_ms(1000);
    ble_stack_init();
    scan_init();
    gap_params_init();
    gatt_init();
    conn_params_init();
    db_discovery_init();
    peer_manager_init();
    hrs_c_init();
    rscs_c_init();
    nus_c_init();
    init_conn_handles();
    services_init();
    advertising_init();

    // Start execution.
    NRF_LOG_INFO("Relay example started.");

    if (erase_bonds == true)
    {
        // Scanning and advertising is done upon PM_EVT_PEERS_DELETE_SUCCEEDED event.
        delete_bonds();
    }
    else
    {
        adv_scan_start();
    }

    while(1)
    {
        if(nrf_gpio_pin_read(KEY1)==0)
         {
             nrf_delay_ms(1000);
             Display_Clear();
             Display_Goto(1,10);
             Display_Puts("NURSE IN ");
             uint16_t length = strlen("NURSE IN ");
             ble_nus_data_send(&m_nus,"NURSE IN", &length, m_conn_handle);
            // NRF_LOG_INFO("BUTTON 1 PRESSED ");

         }
        else if(nrf_gpio_pin_read(KEY2)==0)
         {
             nrf_delay_ms(1000);
             Display_Clear();
             Display_Goto(1,10);
             Display_Puts("NURSE OUT");
             uint16_t length = strlen("NURSE OUT ");
             ble_nus_data_send(&m_nus,"NURSE OUT", &length, m_conn_handle);
             //NRF_LOG_INFO("BUTTON 2 PRESSED ");

         }
         //else
         //{
         //    Display_Clear();
         //    Display_Goto(1,10);
         //    Display_Puts("ELSE");
         //    //nrf_delay_ms(1000);

         //}
         idle_state_handle();
           
    }

    // Enter main loop.
    //for (;;)
    //{
    //     if(nrf_gpio_pin_read(KEY1)==0)
    //     {
    //         //nrf_delay_ms(1000);
    //         Display_Clear();
    //         Display_Goto(1,10);
    //         Display_Puts("NURSE IN ");
    //         //uint16_t length = strlen("NURSE IN ");
    //         //ble_nus_data_send(&m_nus,"NURSE IN", &length, m_conn_handle);
    //        // NRF_LOG_INFO("BUTTON 1 PRESSED ");

    //     }
    //    idle_state_handle();
    //}
}

RE: Trouble Reconnecting Peripherals after Disconnection.

siltvm — Thu, 19 Dec 2024 08:54:07 GMT

i will attach the gateway code for better understanding .

/**
 * Copyright (c) 2014 - 2020, Nordic Semiconductor ASA
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form, except as embedded into a Nordic
 *    Semiconductor ASA integrated circuit in a product or a software update for
 *    such product, must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * 4. This software, with or without modification, must only be used with a
 *    Nordic Semiconductor ASA integrated circuit.
 *
 * 5. Any software provided in binary form under this license must not be reverse
 *    engineered, decompiled, modified and/or disassembled.
 *
 * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */
/**
 * @brief BLE Heart Rate and Running Speed relay application main file.
 *
 * @detail This application demonstrates a simple relay, which passes on the values it receives.
 * By combining a collector part on one end and a sensor part on the other,
 * the s130 can function simultaneously as a central and a peripheral device.
 * 
 * The following figure shows how the sensor ble_app_hrs connects and interacts with the relay
 * in the same manner it would connect to a Heart Rate Collector. In this case, the relay
 * application acts as a central.
 *
 * On the other side, a collector (such as Master Control Panel or ble_app_hrs_c) connects
 * and interacts with the relay in the same manner it would connect to a heart rate sensor peripheral.
 *
 * LED layout:
 * LED 1: Central side is scanning.       LED 2: Central side is connected to a peripheral.
 * LED 3: Peripheral side is advertising. LED 4: Peripheral side is connected to a central.
 *
 * @note While testing, make sure that the Sensor and Collector are actually connecting to the relay,
 *       and not directly to each other!
 *
 *    Peripheral                  Relay                    Central
 *    +--------+        +-----------|----------+        +-----------+
 *    | Heart  |        | Heart     |   Heart  |        |           |
 *    | Rate   | -----> | Rate     -|-> Rate   | -----> | Collector |
 *    | Sensor |        | Collector |   Sensor |        |           |
 *    +--------+        +-----------|   and    |        +-----------+
 *                      | Running   |   Running|
 *    +--------+        | Speed    -|-> Speed  |
 *    | Running|------> | Collector |   Sensor |
 *    | Speed  |        +-----------|----------+
 *    | Sensor |
 *    +--------+
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "nordic_common.h"
#include "nrf_sdh.h"
#include "nrf_sdh_soc.h"
#include "nrf_sdh_ble.h"
#include "peer_manager.h"
#include "peer_manager_handler.h"
#include "app_timer.h"
#include "bsp_btn_ble.h"
#include "ble.h"
#include "ble_advdata.h"
#include "ble_advertising.h"
#include "ble_conn_params.h"
#include "ble_db_discovery.h"
#include "ble_hrs.h"
#include "ble_rscs.h"
#include "ble_hrs_c.h"
#include "ble_rscs_c.h"
#include "ble_conn_state.h"
#include "ble_nus.h"
#include "ble_nus_c.h"
#include "nrf_fstorage.h"
#include "fds.h"
#include "nrf_ble_gatt.h"
#include "nrf_ble_qwr.h"
#include "nrf_pwr_mgmt.h"
#include "nrf_ble_scan.h"

#include "nrf_log.h"
#include "nrf_log_ctrl.h"
#include "nrf_log_default_backends.h"


char Bledatabuff[64];

#define PERIPHERAL_ADVERTISING_LED      BSP_BOARD_LED_2
#define PERIPHERAL_CONNECTED_LED        BSP_BOARD_LED_3
#define CENTRAL_SCANNING_LED            BSP_BOARD_LED_0
#define CENTRAL_CONNECTED_LED           BSP_BOARD_LED_1

#define DEVICE_NAME                     "nRF Relay"                                 /**< Name of device used for advertising. */
#define MANUFACTURER_NAME               "NordicSemiconductor"                       /**< Manufacturer. Passed to Device Information Service. */
#define APP_ADV_INTERVAL                300                                         /**< The advertising interval (in units of 0.625 ms). This value corresponds to 187.5 ms. */

#define APP_ADV_DURATION                18000                                       /**< The advertising duration (180 seconds) in units of 10 milliseconds. */

#define APP_BLE_CONN_CFG_TAG            1                                           /**< Tag that identifies the SoftDevice BLE configuration. */

#define FIRST_CONN_PARAMS_UPDATE_DELAY  APP_TIMER_TICKS(5000)                       /**< Time from initiating event (connect or start of notification) to the first time sd_ble_gap_conn_param_update is called (5 seconds). */
#define NEXT_CONN_PARAMS_UPDATE_DELAY   APP_TIMER_TICKS(30000)                      /**< Time between each call to sd_ble_gap_conn_param_update after the first call (30 seconds). */
#define MAX_CONN_PARAMS_UPDATE_COUNT    3                                           /**< Number of attempts before giving up the connection parameter negotiation. */

#define SEC_PARAM_BOND                  1                                           /**< Perform bonding. */
#define SEC_PARAM_MITM                  0                                           /**< Man In The Middle protection not required. */
#define SEC_PARAM_LESC                  0                                           /**< LE Secure Connections not enabled. */
#define SEC_PARAM_KEYPRESS              0                                           /**< Keypress notifications not enabled. */
#define SEC_PARAM_IO_CAPABILITIES       BLE_GAP_IO_CAPS_NONE                        /**< No I/O capabilities. */
#define SEC_PARAM_OOB                   0                                           /**< Out Of Band data not available. */
#define SEC_PARAM_MIN_KEY_SIZE          7                                           /**< Minimum encryption key size in octets. */
#define SEC_PARAM_MAX_KEY_SIZE          16                                          /**< Maximum encryption key size in octets. */

#define HART_RATE_SERVICE_UUID_IDX      0                                           /**< Hart Rate service UUID index in array. */
#define RSCS_SERVICE_UUID_IDX           1                                           /**< RSCS service UUID index in array. */

#define NUS_SERVICE_UUID_TYPE   BLE_UUID_TYPE_VENDOR_BEGIN              /**< UUID type for the Nordic UART Service (vendor specific). */
/**@brief   Priority of the application BLE event handler.
 * @note    You shouldn't need to modify this value.
 */
#define APP_BLE_OBSERVER_PRIO           3

#define DB_DISCOVERY_INSTANCE_CNT       2  /**< Number of DB Discovery instances. */

static ble_hrs_t m_hrs;                                             /**< Heart Rate Service instance. */
static ble_rscs_t m_rscs;                                           /**< Running Speed and Cadence Service instance. */
static ble_hrs_c_t m_hrs_c;                                         /**< Heart Rate Service client instance. */
static ble_rscs_c_t m_rscs_c; 
                                      /**< Running Speed and Cadence Service client instance. */
BLE_NUS_C_ARRAY_DEF(m_ble_nus_c_arr, NRF_SDH_BLE_CENTRAL_LINK_COUNT);

//BLE_NUS_C_DEF(m_ble_nus_c);                                        /**< BLE Nordic UART Service (NUS) client instance. */
BLE_NUS_DEF(m_nus, NRF_SDH_BLE_TOTAL_LINK_COUNT);                   // peripherel instance of NUS  ( modified )

NRF_BLE_GQ_DEF(m_ble_gatt_queue,                                    /**< BLE GATT Queue instance. */
               NRF_SDH_BLE_CENTRAL_LINK_COUNT,
               NRF_BLE_GQ_QUEUE_SIZE);
NRF_BLE_GATT_DEF(m_gatt);                                              /**< GATT module instance. */
NRF_BLE_QWRS_DEF(m_qwr, NRF_SDH_BLE_TOTAL_LINK_COUNT);                 /**< Context for the Queued Write module.*/
BLE_ADVERTISING_DEF(m_advertising);                                    /**< Advertising module instance. */
BLE_DB_DISCOVERY_ARRAY_DEF(m_db_discovery, 2);                         /**< Database discovery module instances. */
NRF_BLE_SCAN_DEF(m_scan);                                           /**< Scanning module instance. */
static uint16_t m_conn_handle          = BLE_CONN_HANDLE_INVALID;                 /**< Handle of the current connection. */
static uint16_t m_conn_handle_hrs_c  = BLE_CONN_HANDLE_INVALID;     /**< Connection handle for the HRS central application */
static uint16_t m_conn_handle_rscs_c = BLE_CONN_HANDLE_INVALID;     /**< Connection handle for the RSC central application */
//static uint16_t m_conn_handle_nus_c  = BLE_CONN_HANDLE_INVALID;     /**< Handle of the current connection for the nus  */

static uint16_t m_conn_handle_nus_c_arr[NRF_SDH_BLE_CENTRAL_LINK_COUNT];


static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
/**@brief Names that the central application scans for, and that are advertised by the peripherals.
 *  If these are set to empty strings, the UUIDs defined below are used.
 */
static char const m_target_periph_name[] = "";

/**@brief UUIDs that the central application scans for if the name above is set to an empty string,
 * and that are to be advertised by the peripherals.
 */
static ble_uuid_t m_adv_uuids[] =
{
    {BLE_UUID_HEART_RATE_SERVICE,        BLE_UUID_TYPE_BLE},
    {BLE_UUID_RUNNING_SPEED_AND_CADENCE, BLE_UUID_TYPE_BLE}
};


/**@brief NUS UUID. */
static ble_uuid_t const m_nus_uuid =
{
    .uuid = BLE_UUID_NUS_SERVICE,
    .type = NUS_SERVICE_UUID_TYPE
};

void init_conn_handles(void)
{
    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        m_conn_handle_nus_c_arr[i] = BLE_CONN_HANDLE_INVALID;
    }
}
static ble_gap_scan_params_t m_scan_param =                 /**< Scan parameters requested for scanning and connection. */
{
    .active        = 0x01,
    .interval      = NRF_BLE_SCAN_SCAN_INTERVAL,
    .window        = NRF_BLE_SCAN_SCAN_WINDOW,
    .filter_policy = BLE_GAP_SCAN_FP_ACCEPT_ALL,
    .timeout       = NRF_BLE_SCAN_SCAN_DURATION,
    .scan_phys     = BLE_GAP_PHY_1MBPS,
    .extended      = true,
};


/**@brief Function for handling asserts in the SoftDevice.
 *
 * @details This function is called in case of an assert in the SoftDevice.
 *
 * @warning This handler is an example only and is not meant for the final product. You need to analyze
 *          how your product is supposed to react in case of assert.
 * @warning On assert from the SoftDevice, the system can only recover on reset.
 *
 * @param[in] line_num     Line number of the failing assert call.
 * @param[in] p_file_name  File name of the failing assert call.
 */
void assert_nrf_callback(uint16_t line_num, const uint8_t * p_file_name)
{
    app_error_handler(0xDEADBEEF, line_num, p_file_name);
}


/**@brief Function for handling the Heart Rate Service Client
 *        Running Speed and Cadence Service Client.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void service_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


/**@brief Function for handling errors from the Connection Parameters module.
 *
 * @param[in] nrf_error  Error code containing information about what went wrong.
 */
static void conn_params_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


static void scan_evt_handler(scan_evt_t const * p_scan_evt)
{
    ret_code_t err_code;
    ble_gap_evt_adv_report_t const * p_adv = 
                   p_scan_evt->params.filter_match.p_adv_report;
    ble_gap_scan_params_t    const * p_scan_param = 
                   p_scan_evt->p_scan_params;

    switch(p_scan_evt->scan_evt_id)
    {
        case NRF_BLE_SCAN_EVT_FILTER_MATCH:
        {
            // Initiate connection.
            err_code = sd_ble_gap_connect(&p_adv->peer_addr,
                                          p_scan_param,
                                          &m_scan.conn_params,
                                          APP_BLE_CONN_CFG_TAG);
            APP_ERROR_CHECK(err_code);
        } break;

        case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
        {
            err_code = p_scan_evt->params.connecting_err.err_code;
            APP_ERROR_CHECK(err_code);
        } break;

        case NRF_BLE_SCAN_EVT_CONNECTED:
        {
            ble_gap_evt_connected_t const * p_connected = p_scan_evt->params.connected.p_connected;
            NRF_LOG_INFO("Connected to target %02x%02x%02x%02x%02x%02x",
                         p_connected->peer_addr.addr[5],
                         p_connected->peer_addr.addr[4],
                         p_connected->peer_addr.addr[3],
                         p_connected->peer_addr.addr[2],
                         p_connected->peer_addr.addr[1],
                         p_connected->peer_addr.addr[0]);
        } break;


        default:
            break;
    }
}


/**@brief Function for initialization the scanning and setting the filters.
 */
static void scan_init(void)
{
    ret_code_t          err_code;
    nrf_ble_scan_init_t init_scan;

    memset(&init_scan, 0, sizeof(init_scan));

    init_scan.p_scan_param = &m_scan_param;
    //init_scan.connect_if_match = true;
    //init_scan.conn_cfg_tag     = APP_BLE_CONN_CFG_TAG;

    err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_scan_init : %d\n",err_code);

    if (strlen(m_target_periph_name) != 0)
    {
        err_code = nrf_ble_scan_filter_set(&m_scan, 
                                           SCAN_NAME_FILTER, 
                                           m_target_periph_name);
        NRF_LOG_INFO("SCAN_NAME_FILTER : %d\n",err_code);
        APP_ERROR_CHECK(err_code);
    }

    err_code = nrf_ble_scan_filter_set(&m_scan, 
                                       SCAN_UUID_FILTER, 
                                       &m_adv_uuids[HART_RATE_SERVICE_UUID_IDX]);
    NRF_LOG_INFO("scan filter init HART_RATE_SERVICE_UUID_IDX : %d\n",err_code);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_scan_filter_set(&m_scan, 
                                       SCAN_UUID_FILTER, 
                                       &m_adv_uuids[RSCS_SERVICE_UUID_IDX]);
    NRF_LOG_INFO("scan filter init RSCS_SERVICE_UUID_IDX : %d\n",err_code);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_UUID_FILTER, &m_nus_uuid);
    NRF_LOG_INFO("scan filter init NUS : %d\n",err_code);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_scan_filters_enable(&m_scan, 
                                           NRF_BLE_SCAN_ALL_FILTER, 
                                           false);
    NRF_LOG_INFO("nrf_ble_scan_filters_enable : %d\n",err_code);
    APP_ERROR_CHECK(err_code);

}


/**@brief Function for initializing the scanning.
 */
static void scan_start(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_scan_start(&m_scan);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_scan_start : %d\n",err_code);
    NRF_LOG_INFO("SCAN START");
}


/**@brief Function for initializing the advertising and the scanning.
 */
static void adv_scan_start(void)
{
    ret_code_t err_code;

    //check if there are no flash operations in progress
    if (!nrf_fstorage_is_busy(NULL))
    {
        // Start scanning for peripherals and initiate connection to devices which
        // advertise Heart Rate or Running speed and cadence UUIDs.
        scan_start();

        // Turn on the LED to signal scanning.
        bsp_board_led_on(CENTRAL_SCANNING_LED);

        // Start advertising.
        err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
        APP_ERROR_CHECK(err_code);
    }
}


/**@brief Function for handling Peer Manager events.
 *
 * @param[in] p_evt  Peer Manager event.
 */
static void pm_evt_handler(pm_evt_t const * p_evt)
{
    NRF_LOG_INFO("ENTER IN PM EVNT HANDLER ");
    pm_handler_on_pm_evt(p_evt);
    pm_handler_disconnect_on_sec_failure(p_evt);
    pm_handler_flash_clean(p_evt);

    switch (p_evt->evt_id)
    {
        case PM_EVT_PEERS_DELETE_SUCCEEDED:
            adv_scan_start();
            break;

        default:
            break;
    }
}


/**@brief Function for changing filter settings after establishing the connection.
 */
static void filter_settings_change(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_scan_all_filter_remove(&m_scan);
    APP_ERROR_CHECK(err_code);

    if (strlen(m_target_periph_name) != 0)
    {
        err_code = nrf_ble_scan_filter_set(&m_scan, 
                                           SCAN_NAME_FILTER, 
                                           m_target_periph_name);
        APP_ERROR_CHECK(err_code);
    }

    if ((m_conn_handle_hrs_c != BLE_CONN_HANDLE_INVALID) && 
        (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID))
    {
        err_code = nrf_ble_scan_filter_set(&m_scan, 
                                           SCAN_UUID_FILTER, 
                                           &m_adv_uuids[RSCS_SERVICE_UUID_IDX]);
    }

    if ((m_conn_handle_rscs_c != BLE_CONN_HANDLE_INVALID) && 
         m_conn_handle_hrs_c == BLE_CONN_HANDLE_INVALID)
    {
        err_code = nrf_ble_scan_filter_set(&m_scan, 
                                           SCAN_UUID_FILTER, 
                                           &m_adv_uuids[HART_RATE_SERVICE_UUID_IDX]);
    }

    APP_ERROR_CHECK(err_code);
}


/**@brief Handles events coming from the Heart Rate central module.
 */
static void hrs_c_evt_handler(ble_hrs_c_t * p_hrs_c, ble_hrs_c_evt_t * p_hrs_c_evt)
{
    switch (p_hrs_c_evt->evt_type)
    {
        case BLE_HRS_C_EVT_DISCOVERY_COMPLETE:
        {
            if (m_conn_handle_hrs_c == BLE_CONN_HANDLE_INVALID)
            {
                ret_code_t err_code;

                m_conn_handle_hrs_c = p_hrs_c_evt->conn_handle;
                NRF_LOG_INFO("HRS discovered on conn_handle 0x%x", m_conn_handle_hrs_c);

                filter_settings_change();

                err_code = ble_hrs_c_handles_assign(p_hrs_c,
                                                    m_conn_handle_hrs_c,
                                                    &p_hrs_c_evt->params.peer_db);
                APP_ERROR_CHECK(err_code);
                // Initiate bonding.
                err_code = pm_conn_secure(m_conn_handle_hrs_c, false);
                if (err_code != NRF_ERROR_BUSY)
                {
                    APP_ERROR_CHECK(err_code);
                }

                // Heart rate service discovered. Enable notification of Heart Rate Measurement.
                err_code = ble_hrs_c_hrm_notif_enable(p_hrs_c);
                APP_ERROR_CHECK(err_code);
            }
        } break; // BLE_HRS_C_EVT_DISCOVERY_COMPLETE

        case BLE_HRS_C_EVT_HRM_NOTIFICATION:
        {
            ret_code_t err_code;

            NRF_LOG_INFO("Heart Rate = %d", p_hrs_c_evt->params.hrm.hr_value);

            err_code = ble_hrs_heart_rate_measurement_send(&m_hrs, p_hrs_c_evt->params.hrm.hr_value);
            if ((err_code != NRF_SUCCESS) &&
                (err_code != NRF_ERROR_INVALID_STATE) &&
                (err_code != NRF_ERROR_RESOURCES) &&
                (err_code != NRF_ERROR_BUSY) &&
                (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
                )
            {
                APP_ERROR_HANDLER(err_code);
            }
        } break; // BLE_HRS_C_EVT_HRM_NOTIFICATION

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Handles events coming from  Running Speed and Cadence central module.
 */
static void rscs_c_evt_handler(ble_rscs_c_t * p_rscs_c, ble_rscs_c_evt_t * p_rscs_c_evt)
{
    switch (p_rscs_c_evt->evt_type)
    {
        case BLE_RSCS_C_EVT_DISCOVERY_COMPLETE:
        {
            if (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID)
            {
                ret_code_t err_code;

                m_conn_handle_rscs_c = p_rscs_c_evt->conn_handle;
                NRF_LOG_INFO("Running Speed and Cadence service discovered on conn_handle 0x%x",
                             m_conn_handle_rscs_c);

                filter_settings_change();

                err_code = ble_rscs_c_handles_assign(p_rscs_c,
                                                    m_conn_handle_rscs_c,
                                                    &p_rscs_c_evt->params.rscs_db);
                APP_ERROR_CHECK(err_code);

                // Initiate bonding.
                err_code = pm_conn_secure(m_conn_handle_rscs_c, false);
                if (err_code != NRF_ERROR_BUSY)
                {
                    APP_ERROR_CHECK(err_code);
                }

                // Running Speed Cadence Service discovered. Enable notifications.
                err_code = ble_rscs_c_rsc_notif_enable(p_rscs_c);
                APP_ERROR_CHECK(err_code);
            }
        } break; // BLE_RSCS_C_EVT_DISCOVERY_COMPLETE:

        case BLE_RSCS_C_EVT_RSC_NOTIFICATION:
        {
            ret_code_t      err_code;
            ble_rscs_meas_t rscs_measurment;

            NRF_LOG_INFO("Speed      = %d", p_rscs_c_evt->params.rsc.inst_speed);

            rscs_measurment.is_running                  = p_rscs_c_evt->params.rsc.is_running;
            rscs_measurment.is_inst_stride_len_present  = p_rscs_c_evt->params.rsc.is_inst_stride_len_present;
            rscs_measurment.is_total_distance_present   = p_rscs_c_evt->params.rsc.is_total_distance_present;

            rscs_measurment.inst_stride_length = p_rscs_c_evt->params.rsc.inst_stride_length;
            rscs_measurment.inst_cadence       = p_rscs_c_evt->params.rsc.inst_cadence;
            rscs_measurment.inst_speed         = p_rscs_c_evt->params.rsc.inst_speed;
            rscs_measurment.total_distance     = p_rscs_c_evt->params.rsc.total_distance;

            err_code = ble_rscs_measurement_send(&m_rscs, &rscs_measurment);
            if ((err_code != NRF_SUCCESS) &&
                (err_code != NRF_ERROR_INVALID_STATE) &&
                (err_code != NRF_ERROR_RESOURCES) &&
                (err_code != NRF_ERROR_BUSY) &&
                (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
                )
            {
                APP_ERROR_HANDLER(err_code);
            }
        } break; // BLE_RSCS_C_EVT_RSC_NOTIFICATION

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for assigning new connection handle to available instance of QWR module.
 *
 * @param[in] conn_handle New connection handle.
 */
static void multi_qwr_conn_handle_assign(uint16_t conn_handle)
{
    for (uint32_t i = 0; i < NRF_SDH_BLE_TOTAL_LINK_COUNT; i++)
    {
        if (m_qwr[i].conn_handle == BLE_CONN_HANDLE_INVALID)
        {
            ret_code_t err_code = nrf_ble_qwr_conn_handle_assign(&m_qwr[i], conn_handle);
            APP_ERROR_CHECK(err_code);
            break;
        }
    }
}


/**@brief   Function for handling BLE events from the central application.
 *
 * @details This function parses scanning reports and initiates a connection to peripherals when a
 *          target UUID is found. It updates the status of LEDs used to report the central application
 *          activity.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 */
static void on_ble_central_evt(ble_evt_t const * p_ble_evt)
{
    ret_code_t            err_code;
    ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;

    switch (p_ble_evt->header.evt_id)
    {
        // Upon connection, check which peripheral is connected (HR or RSC), initiate DB
        // discovery, update LEDs status, and resume scanning, if necessary.
        case BLE_GAP_EVT_CONNECTED:
        {
            NRF_LOG_INFO("Central connected");
            // If no Heart Rate sensor or RSC sensor is currently connected, try to find them on this peripheral.
            // Attempt to find HRS, RSC, or NUS on the connected peripheral.
            for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
            {
                if (   (m_conn_handle_hrs_c  == BLE_CONN_HANDLE_INVALID)
                    || (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID)
                    || (m_conn_handle_nus_c_arr[i] == BLE_CONN_HANDLE_INVALID)) // Check for free slot in NUS connections.
                {
                    NRF_LOG_INFO("Attempt to find HRS, RSC, or NUS conn_handle 0x%x", p_gap_evt->conn_handle);

                    err_code = ble_db_discovery_start(&m_db_discovery[i], p_gap_evt->conn_handle);
                    if (err_code != NRF_ERROR_BUSY)
                    {
                        APP_ERROR_CHECK(err_code);
                        break;
                    }
                }
            }

            // Assign connection handle to NUS Client
            for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
            {
                if (m_conn_handle_nus_c_arr[i] == BLE_CONN_HANDLE_INVALID)
                {
                    err_code = ble_nus_c_handles_assign(&m_ble_nus_c_arr[i], p_gap_evt->conn_handle, NULL);
                    APP_ERROR_CHECK(err_code);
                    m_conn_handle_nus_c_arr[i] = p_gap_evt->conn_handle;
                    NRF_LOG_INFO("NUS client assigned to conn_handle 0x%x (index: %d)", p_gap_evt->conn_handle, i);
                    break;
                }
            }
            // Assign connection handle to NUS Client
            //err_code = ble_nus_c_handles_assign(&m_ble_nus_c, p_ble_evt->evt.gap_evt.conn_handle, NULL);  //added nus handle assigning 
            //APP_ERROR_CHECK(err_code);

            // Assign connection handle to the QWR module.
            multi_qwr_conn_handle_assign(p_gap_evt->conn_handle);

            // Update LEDs status, and check whether to look for more peripherals to connect to.
            bsp_board_led_on(CENTRAL_CONNECTED_LED);
            if (ble_conn_state_central_conn_count() == NRF_SDH_BLE_CENTRAL_LINK_COUNT)
            {
                bsp_board_led_off(CENTRAL_SCANNING_LED);
            }
            else
            {
                // Resume scanning.
                bsp_board_led_on(CENTRAL_SCANNING_LED);
                scan_start();
            }
        } break; // BLE_GAP_EVT_CONNECTED

        // Upon disconnection, reset the connection handle of the peer that disconnected,
        // update the LEDs status and start scanning again.
        case BLE_GAP_EVT_DISCONNECTED:
        {

         NRF_LOG_INFO("Device disconnected, conn_handle: 0x%x, reason: 0x%x",
                         p_gap_evt->conn_handle,
                         p_gap_evt->params.disconnected.reason);

            if (p_gap_evt->conn_handle == m_conn_handle_hrs_c)
            {
                NRF_LOG_INFO("HRS central disconnected (reason: %d)",
                             p_gap_evt->params.disconnected.reason);

                m_conn_handle_hrs_c = BLE_CONN_HANDLE_INVALID;
                
                err_code = nrf_ble_scan_filter_set(&m_scan, 
                                                   SCAN_UUID_FILTER, 
                                                   &m_adv_uuids[HART_RATE_SERVICE_UUID_IDX]);
                NRF_LOG_INFO("HRS service disconnected.");
                APP_ERROR_CHECK(err_code);
            }

            if (p_gap_evt->conn_handle == m_conn_handle_rscs_c)
            {
                NRF_LOG_INFO("RSC central disconnected (reason: %d)",
                             p_gap_evt->params.disconnected.reason);

                m_conn_handle_rscs_c = BLE_CONN_HANDLE_INVALID;

                err_code = nrf_ble_scan_filter_set(&m_scan, 
                                                   SCAN_UUID_FILTER, 
                                                   &m_adv_uuids[RSCS_SERVICE_UUID_IDX]);
                                              
                NRF_LOG_INFO("RSCS service disconnected.");
                APP_ERROR_CHECK(err_code);
            }


            //if (p_gap_evt->conn_handle == m_conn_handle_nus_c)
            //{
            //    m_conn_handle_nus_c = BLE_CONN_HANDLE_INVALID;
            //    NRF_LOG_INFO("NUS service disconnected.");
            //}

            for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
            {
                if (p_gap_evt->conn_handle == m_conn_handle_nus_c_arr[i])
                {
                    m_conn_handle_nus_c_arr[i] = BLE_CONN_HANDLE_INVALID;
                    NRF_LOG_INFO("NUS service disconnected (index: %d)", i);
                    break;
                }
            }


            //if (   (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID)
            //    || (m_conn_handle_hrs_c  == BLE_CONN_HANDLE_INVALID)||(m_conn_handle_nus_c==BLE_CONN_HANDLE_INVALID)) //added nus connection handle checking
            //{
            //    // Start scanning.
            //    scan_start();

            //    // Update LEDs status.
            //    bsp_board_led_on(CENTRAL_SCANNING_LED);
            //}

            // Check if any connection handle is invalid and restart scanning if needed
    bool any_invalid_handle = (m_conn_handle_hrs_c == BLE_CONN_HANDLE_INVALID) ||
                              (m_conn_handle_rscs_c == BLE_CONN_HANDLE_INVALID);
    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        if (m_conn_handle_nus_c_arr[i] == BLE_CONN_HANDLE_INVALID)
        {
            any_invalid_handle = true;
            break;
        }
    }

    if (any_invalid_handle)
    {
        // Restart scanning if there is any invalid connection handle
        scan_start();

        // Update LEDs to indicate scanning
        bsp_board_led_on(CENTRAL_SCANNING_LED);
    }

            if (ble_conn_state_central_conn_count() == 0)
            {
                
                bsp_board_led_off(CENTRAL_CONNECTED_LED);
            }
        } break; // BLE_GAP_EVT_DISCONNECTED

        case BLE_GAP_EVT_TIMEOUT:
        {
            // No timeout for scanning is specified, so only connection attemps can timeout.
            if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN)
            {
                NRF_LOG_INFO("Connection Request timed out.");
            }
        } break;

        case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
        {
            // Accept parameters requested by peer.
            err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
                                        &p_gap_evt->params.conn_param_update_request.conn_params);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_DEBUG("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_DEBUG("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief   Function for handling BLE events from peripheral applications.
 * @details Updates the status LEDs used to report the activity of the peripheral applications.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 */
static void on_ble_peripheral_evt(ble_evt_t const * p_ble_evt)
{
    ret_code_t            err_code;
    ble_gap_evt_t const * p_gap_evt = &p_ble_evt->evt.gap_evt;

    switch (p_ble_evt->header.evt_id)
    {
        case BLE_GAP_EVT_CONNECTED:
            NRF_LOG_INFO("Peripheral connected");
            bsp_board_led_off(PERIPHERAL_ADVERTISING_LED);
            bsp_board_led_on(PERIPHERAL_CONNECTED_LED);

            // Assign connection handle to the QWR module.
            m_conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
            multi_qwr_conn_handle_assign(p_ble_evt->evt.gap_evt.conn_handle);
            break;

        case BLE_GAP_EVT_DISCONNECTED:
            NRF_LOG_INFO("Peripheral disconnected. conn_handle: 0x%x, reason: 0x%x",
                         p_gap_evt->conn_handle,
                         p_gap_evt->params.disconnected.reason);

            bsp_board_led_off(PERIPHERAL_CONNECTED_LED);
            break;

        case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
        {
            NRF_LOG_DEBUG("PHY update request.");
            ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
            err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
            APP_ERROR_CHECK(err_code);
        } break;

        case BLE_GATTC_EVT_TIMEOUT:
            // Disconnect on GATT Client timeout event.
            NRF_LOG_DEBUG("GATT Client Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        case BLE_GATTS_EVT_TIMEOUT:
            // Disconnect on GATT Server timeout event.
            NRF_LOG_DEBUG("GATT Server Timeout.");
            err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                             BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
            APP_ERROR_CHECK(err_code);
            break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for handling advertising events.
 *
 * @param[in] ble_adv_evt  Advertising event.
 */
static void on_adv_evt(ble_adv_evt_t ble_adv_evt)
{
    switch (ble_adv_evt)
    {
        case BLE_ADV_EVT_FAST:
        {
            NRF_LOG_INFO("Fast advertising.");
            bsp_board_led_on(PERIPHERAL_ADVERTISING_LED);
        } break;

        case BLE_ADV_EVT_IDLE:
        {
            ret_code_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
            NRF_LOG_INFO("BLE ADV EVT IDLE\n");
            APP_ERROR_CHECK(err_code);
        } break;

        default:
            // No implementation needed.
            break;
    }
}


/**@brief Function for checking whether a bluetooth stack event is an advertising timeout.
 *
 * @param[in] p_ble_evt Bluetooth stack event.
 */
static bool ble_evt_is_advertising_timeout(ble_evt_t const * p_ble_evt)
{
    return (p_ble_evt->header.evt_id == BLE_GAP_EVT_ADV_SET_TERMINATED);
}


/**@brief Function for handling BLE events.
 *
 * @param[in]   p_ble_evt   Bluetooth stack event.
 * @param[in]   p_context   Unused.
 */
static void ble_evt_handler(ble_evt_t const * p_ble_evt, void * p_context)
{
    uint16_t conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
    uint16_t role        = ble_conn_state_role(conn_handle);
    //NRF_LOG_INFO("enter in ble evt handler \n ");
    // Based on the role this device plays in the connection, dispatch to the right handler.
    if (role == BLE_GAP_ROLE_PERIPH || ble_evt_is_advertising_timeout(p_ble_evt))
    {
        //NRF_LOG_INFO("ble gap role peripherel  \n ");
        ble_hrs_on_ble_evt(p_ble_evt, &m_hrs);
        ble_rscs_on_ble_evt(p_ble_evt, &m_rscs);
        ble_nus_on_ble_evt(p_ble_evt, &m_nus);  // Adding this line for NUS peripheral handling
        on_ble_peripheral_evt(p_ble_evt);
    }
    else if ((role == BLE_GAP_ROLE_CENTRAL) || (p_ble_evt->header.evt_id == BLE_GAP_EVT_ADV_REPORT))
    {
        //NRF_LOG_INFO("ble gap role central   \n ");
        ble_hrs_c_on_ble_evt(p_ble_evt, &m_hrs_c);
        ble_rscs_c_on_ble_evt(p_ble_evt, &m_rscs_c);
        for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
        {
          ble_nus_c_on_ble_evt(p_ble_evt, &m_ble_nus_c_arr[i]);
        }
        //ble_nus_c_on_ble_evt(p_ble_evt,&m_ble_nus_c);   // need to check this operation is neccesssary 
        on_ble_central_evt(p_ble_evt);
    }
}

/**@brief Function for handling the Nordic UART Service Client errors.
 *
 * @param[in]   nrf_error   Error code containing information about what went wrong.
 */
static void nus_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}

static void ble_nus_chars_received_log_print(uint8_t * p_data, uint16_t data_len)
{

   NRF_LOG_INFO("ble_nus_chars_received_log_print\n");
   ret_code_t ret_val;
   char received_str[64];
   memset(received_str,0,sizeof(received_str));
   NRF_LOG_DEBUG("Receiving data.");
   NRF_LOG_HEXDUMP_DEBUG(p_data, data_len);
	
   for (uint32_t i = 0; i < data_len; i++)
    {
	 received_str[i]=p_data[i];
    }
	NRF_LOG_INFO("received_str_from_peripherel  : %s\n",received_str);
        uint16_t length=strlen(received_str);
        ret_val = ble_nus_data_send(&m_nus,received_str, &length,m_conn_handle);


}


static void ble_nus_c_evt_handler(ble_nus_c_t * p_ble_nus_c, ble_nus_c_evt_t const * p_ble_nus_evt)
{

 ret_code_t err_code;
 uint8_t instance_index = p_ble_nus_c - m_ble_nus_c_arr; // Calculate the instance index
 NRF_LOG_INFO("current instance index %d\n", instance_index);
 switch (p_ble_nus_evt->evt_type)
 {
  
     case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
          NRF_LOG_INFO("Discovery complete ble_nus_c_evt_handler");
          err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
          APP_ERROR_CHECK(err_code);

          err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
          APP_ERROR_CHECK(err_code);
          NRF_LOG_INFO("Connected to device with Nordic UART Service.");

          m_conn_handle_nus_c_arr[instance_index] = p_ble_nus_evt->conn_handle;

          break;

     case BLE_NUS_C_EVT_NUS_TX_EVT:
          
          ble_nus_chars_received_log_print(p_ble_nus_evt->p_data, p_ble_nus_evt->data_len);
          break;

     case BLE_NUS_C_EVT_DISCONNECTED:
          NRF_LOG_INFO("Disconnected from instance %d", instance_index);
          m_conn_handle_nus_c_arr[instance_index] = BLE_CONN_HANDLE_INVALID;
          //NRF_LOG_INFO("Disconnected");
          scan_start();
          break;


 }
}
/**@brief Function for initializing the Nordic UART Service (NUS) client. */
static void nus_c_init(void)
{
    ret_code_t       err_code;
    ble_nus_c_init_t init;

    init.evt_handler   = ble_nus_c_evt_handler;
    init.error_handler = nus_error_handler;
    init.p_gatt_queue  = &m_ble_gatt_queue;

    //err_code = ble_nus_c_init(&m_ble_nus_c, &init);
    //NRF_LOG_INFO("ble_nus_c_init : %d\n",err_code);
    //APP_ERROR_CHECK(err_code);

    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        err_code = ble_nus_c_init(&m_ble_nus_c_arr[i], &init);
        NRF_LOG_INFO("ble_nus_c_init for instance %d: %d", i, err_code);
        APP_ERROR_CHECK(err_code);
    }
}

/**@brief Heart Rate Collector initialization.
 */
static void hrs_c_init(void)
{
    ret_code_t       err_code;
    ble_hrs_c_init_t hrs_c_init_obj;

    hrs_c_init_obj.evt_handler   = hrs_c_evt_handler;
    hrs_c_init_obj.error_handler = service_error_handler;
    hrs_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

    err_code = ble_hrs_c_init(&m_hrs_c, &hrs_c_init_obj);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_hrs_c_init : %d\n",err_code);
}


/**@brief RSC collector initialization.
 */
static void rscs_c_init(void)
{
    ret_code_t        err_code;
    ble_rscs_c_init_t rscs_c_init_obj;

    rscs_c_init_obj.evt_handler   = rscs_c_evt_handler;
    rscs_c_init_obj.error_handler = service_error_handler;
    rscs_c_init_obj.p_gatt_queue  = &m_ble_gatt_queue;

    err_code = ble_rscs_c_init(&m_rscs_c, &rscs_c_init_obj);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_rscs_c_init : %d\n",err_code);
}


/**@brief Function for initializing the BLE stack.
 *
 * @details Initializes the SoftDevice and the BLE event interrupts.
 */
static void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_sdh_enable_request : %d\n",err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_sdh_ble_default_cfg_set : %d\n",err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_sdh_ble_enable : %d\n",err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
    NRF_LOG_INFO(" after nrf sdh ble observer \n");
}


/**@brief Function for initializing the Peer Manager.
 */
static void peer_manager_init(void)
{
    ble_gap_sec_params_t sec_param;
    ret_code_t err_code;

    err_code = pm_init();
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_init : %d\n",err_code);
    

    memset(&sec_param, 0, sizeof(ble_gap_sec_params_t));

    // Security parameters to be used for all security procedures.
    sec_param.bond           = SEC_PARAM_BOND;
    sec_param.mitm           = SEC_PARAM_MITM;
    sec_param.lesc           = SEC_PARAM_LESC;
    sec_param.keypress       = SEC_PARAM_KEYPRESS;
    sec_param.io_caps        = SEC_PARAM_IO_CAPABILITIES;
    sec_param.oob            = SEC_PARAM_OOB;
    sec_param.min_key_size   = SEC_PARAM_MIN_KEY_SIZE;
    sec_param.max_key_size   = SEC_PARAM_MAX_KEY_SIZE;
    sec_param.kdist_own.enc  = 1;
    sec_param.kdist_own.id   = 1;
    sec_param.kdist_peer.enc = 1;
    sec_param.kdist_peer.id  = 1;

    err_code = pm_sec_params_set(&sec_param);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_sec_params_set : %d\n",err_code);

    err_code = pm_register(pm_evt_handler);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("pm_register : %d\n",err_code);
}


/**@brief Clear bond information from persistent storage.
 */
static void delete_bonds(void)
{
    ret_code_t err_code;

    NRF_LOG_INFO("Erase bonds!");

    err_code = pm_peers_delete();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing buttons and LEDs.
 *
 * @param[out] p_erase_bonds  Will be true if the clear bonding button was pressed to
 *                            wake the application up.
 */
static void buttons_leds_init(bool * p_erase_bonds)
{
    ret_code_t err_code;
    bsp_event_t startup_event;

    err_code = bsp_init(BSP_INIT_LEDS | BSP_INIT_BUTTONS, NULL);
    APP_ERROR_CHECK(err_code);

    err_code = bsp_btn_ble_init(NULL, &startup_event);
    APP_ERROR_CHECK(err_code);

    *p_erase_bonds = (startup_event == BSP_EVENT_CLEAR_BONDING_DATA);
}


/**@brief Function for initializing the GAP.
 *
 * @details This function sets up all the necessary GAP (Generic Access Profile) parameters of the
 *          device, including the device name, appearance, and the preferred connection parameters.
 */
static void gap_params_init(void)
{
    ret_code_t              err_code;
    ble_gap_conn_params_t   gap_conn_params;
    ble_gap_conn_sec_mode_t sec_mode;

    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *)DEVICE_NAME,
                                          strlen(DEVICE_NAME));
    APP_ERROR_CHECK(err_code);

    memset(&gap_conn_params, 0, sizeof(gap_conn_params));

    gap_conn_params.min_conn_interval = m_scan.conn_params.min_conn_interval;
    gap_conn_params.max_conn_interval = m_scan.conn_params.max_conn_interval;
    gap_conn_params.slave_latency     = m_scan.conn_params.slave_latency;
    gap_conn_params.conn_sup_timeout  = m_scan.conn_params.conn_sup_timeout;

    err_code = sd_ble_gap_ppcp_set(&gap_conn_params);
    APP_ERROR_CHECK(err_code);
}

/**@brief Function for handling events from the GATT library. */
void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
{
    if (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED)
    {
        NRF_LOG_INFO("ATT MTU exchange completed.");

        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        NRF_LOG_INFO("Ble NUS max data length set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
}

/**@brief Function for initializing the GATT module.
 */
static void gatt_init(void)
{
    ret_code_t err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_gatt_init : %d\n",err_code);
    // Set the ATT MTU size for central role
    err_code = nrf_ble_gatt_att_mtu_central_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_gatt_att_mtu_central_set : %d\n",err_code);
    // Set the ATT MTU size for peripheral role
    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("nrf_ble_gatt_att_mtu_periph_set : %d\n",err_code);


}


/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    ret_code_t             err_code;
    ble_conn_params_init_t cp_init;

    memset(&cp_init, 0, sizeof(cp_init));

    cp_init.p_conn_params                  = NULL;
    cp_init.first_conn_params_update_delay = FIRST_CONN_PARAMS_UPDATE_DELAY;
    cp_init.next_conn_params_update_delay  = NEXT_CONN_PARAMS_UPDATE_DELAY;
    cp_init.max_conn_params_update_count   = MAX_CONN_PARAMS_UPDATE_COUNT;
    cp_init.start_on_notify_cccd_handle    = BLE_CONN_HANDLE_INVALID; // Start upon connection.
    cp_init.disconnect_on_fail             = true;
    cp_init.evt_handler                    = NULL;  // Ignore events.
    cp_init.error_handler                  = conn_params_error_handler;

    err_code = ble_conn_params_init(&cp_init);
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling database discovery events.
 *
 * @details This function is a callback function to handle events from the database discovery module.
 *          Depending on the UUIDs that are discovered, this function forwards the events
 *          to their respective services.
 *
 * @param[in] p_event  Pointer to the database discovery event.
 */
static void db_disc_handler(ble_db_discovery_evt_t * p_evt)
{
    ble_db_discovery_t const * p_db = (ble_db_discovery_t *)p_evt->params.p_db_instance;

    ble_hrs_on_db_disc_evt(&m_hrs_c, p_evt);
    ble_rscs_on_db_disc_evt(&m_rscs_c, p_evt);
   // ble_nus_c_on_db_disc_evt(&m_ble_nus_c, p_evt);     // nus central db disc evt handler . 

   // Iterate over the NUS client array to find the appropriate instance.
    for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
    {
        if (p_evt->conn_handle == m_conn_handle_nus_c_arr[i])
        {
            ble_nus_c_on_db_disc_evt(&m_ble_nus_c_arr[i], p_evt);
            break;
        }
    }

    if (p_evt->evt_type == BLE_DB_DISCOVERY_AVAILABLE) {
        NRF_LOG_INFO("DB Discovery instance %p available on conn handle: %d",
                     p_db,
                     p_evt->conn_handle);
        NRF_LOG_INFO("Found %d services on conn_handle: %d",
                     p_db->srv_count,
                     p_evt->conn_handle);
    }
}


/**
 * @brief Database discovery initialization.
 */
static void db_discovery_init(void)
{
    ble_db_discovery_init_t db_init;

    memset(&db_init, 0, sizeof(ble_db_discovery_init_t));

    db_init.evt_handler  = db_disc_handler;
    db_init.p_gatt_queue = &m_ble_gatt_queue;

    ret_code_t err_code = ble_db_discovery_init(&db_init);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_db_discovery_init :%d\n",err_code);
}


/**@brief Function for handling Queued Write module errors.
 *
 * @details A pointer to this function is passed to each service that may need to inform the
 *          application about an error.
 *
 * @param[in]   nrf_error   Error code that contains information about what went wrong.
 */
static void nrf_qwr_error_handler(uint32_t nrf_error)
{
    APP_ERROR_HANDLER(nrf_error);
}


static void nus_data_handler(ble_nus_evt_t * p_evt)
{

  memset(Bledatabuff,0,sizeof(Bledatabuff));
  uint16_t data_len=0;
  ret_code_t ret_val;
  // write the code for nus data handling .
   if (p_evt->type == BLE_NUS_EVT_RX_DATA)
    {
        NRF_LOG_DEBUG("Received data from BLE NUS.");

        // Copy received data to Bledatabuff array
        for (uint32_t i = 0; i < p_evt->params.rx_data.length; i++)
        {
            Bledatabuff[i] = p_evt->params.rx_data.p_data[i];
        }
        for (uint8_t i = 0; i < NRF_SDH_BLE_CENTRAL_LINK_COUNT; i++)
        {
        if (m_conn_handle_nus_c_arr[i] != BLE_CONN_HANDLE_INVALID)
        {
         data_len=strlen(Bledatabuff);
         ret_code_t err_code = ble_nus_c_string_send(&m_ble_nus_c_arr[i],Bledatabuff,data_len);
          if (err_code != NRF_SUCCESS)
                {
                    NRF_LOG_ERROR("Failed to forward data to instance %d: %d", i, err_code);
                }
         }

        }
    }
   // NRF_LOG_INFO(" Received ble data : %s\n",Bledatabuff );
   // data_len=strlen(Bledatabuff);
   // ret_val=ble_nus_c_string_send(&m_ble_nus_c, Bledatabuff, data_len);
   // NRF_LOG_INFO("ble_nus_c_string_send : %d\n",ret_val);


}
/**@brief Function for initializing services that are be used by the application.
 *
 * @details Initialize the Heart Rate, Battery and Device Information services.
 */
static void services_init(void)
{
    ret_code_t         err_code;
    ble_hrs_init_t     hrs_init;
    ble_rscs_init_t    rscs_init;
    ble_nus_init_t     nus_init;
    nrf_ble_qwr_init_t qwr_init = {0};
    uint8_t            body_sensor_location;

   

    // Initialize Queued Write module instances.
    qwr_init.error_handler = nrf_qwr_error_handler;

    for (uint32_t i = 0; i < NRF_SDH_BLE_TOTAL_LINK_COUNT; i++)
    {
        err_code = nrf_ble_qwr_init(&m_qwr[i], &qwr_init);
        APP_ERROR_CHECK(err_code);
        NRF_LOG_INFO("nrf_ble_qwr_init : %d\n",err_code);
    }

    // Initialize the Heart Rate Service.
    body_sensor_location = BLE_HRS_BODY_SENSOR_LOCATION_FINGER;

    memset(&hrs_init, 0, sizeof(hrs_init));

    hrs_init.evt_handler                 = NULL;
    hrs_init.is_sensor_contact_supported = true;
    hrs_init.p_body_sensor_location      = &body_sensor_location;

    // Here the sec level for the Heart Rate Service can be changed or increased.
    hrs_init.hrm_cccd_wr_sec = SEC_OPEN;
    hrs_init.bsl_rd_sec      = SEC_OPEN;

    err_code = ble_hrs_init(&m_hrs, &hrs_init);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_hrs_init : %d\n",err_code);

    // Initialize the Running Speed and Cadence Service.
    memset(&rscs_init, 0, sizeof(rscs_init));

    rscs_init.evt_handler = NULL;
    rscs_init.feature     = BLE_RSCS_FEATURE_INSTANT_STRIDE_LEN_BIT |
                            BLE_RSCS_FEATURE_WALKING_OR_RUNNING_STATUS_BIT;

    // Here the sec level for the Running Speed and Cadence Service can be changed or increased.
    rscs_init.rsc_feature_rd_sec   = SEC_OPEN;
    rscs_init.rsc_meas_cccd_wr_sec = SEC_OPEN;

    err_code = ble_rscs_init(&m_rscs, &rscs_init);
    APP_ERROR_CHECK(err_code);
    NRF_LOG_INFO("ble_rscs_init : %d\n ",err_code);

    memset(&nus_init, 0, sizeof(nus_init));     
    nus_init.data_handler = nus_data_handler;    //intialisation parts for the nus 
    err_code = ble_nus_init(&m_nus, &nus_init);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_INFO(" ble_nus_init : %d\n",err_code);

}


/**@brief Function for initializing the advertising functionality.
 */
static void advertising_init(void)
{
    ret_code_t             err_code;
    ble_advertising_init_t init;

    memset(&init, 0, sizeof(init));

    init.advdata.name_type               = BLE_ADVDATA_FULL_NAME;
    init.advdata.include_appearance      = true;
    init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
    init.advdata.uuids_complete.uuid_cnt = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    init.advdata.uuids_complete.p_uuids  = m_adv_uuids;

    init.config.ble_adv_fast_enabled  = true;
    init.config.ble_adv_fast_interval = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout  = APP_ADV_DURATION;

    init.evt_handler = on_adv_evt;

    err_code = ble_advertising_init(&m_advertising, &init);
    APP_ERROR_CHECK(err_code);

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}


/**@brief Function for initializing logging.
 */
static void log_init(void)
{
    ret_code_t err_code = NRF_LOG_INIT(NULL);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEFAULT_BACKENDS_INIT();
}


/**@brief Function for initializing power management.
 */
static void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for handling the idle state (main loop). If there is no pending log operation,
          then sleeps until the next event occurs.
 */
static void idle_state_handle(void)
{
    if (NRF_LOG_PROCESS() == false)
    {
        nrf_pwr_mgmt_run();
    }
}


/**@brief Function for initializing the timer.
 */
static void timer_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}


/**@brief Function for initializing the application main entry.
 */
int main(void)
{
    bool erase_bonds;

    // Initialize.
    log_init();
    timer_init();
    buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    scan_init();
    gap_params_init();
    gatt_init();
    conn_params_init();
    db_discovery_init();
    peer_manager_init();
    hrs_c_init();
    rscs_c_init();
    nus_c_init();
    init_conn_handles();
    services_init();
    advertising_init();

    // Start execution.
    NRF_LOG_INFO("Relay example started.");

    if (erase_bonds == true)
    {
        // Scanning and advertising is done upon PM_EVT_PEERS_DELETE_SUCCEEDED event.
        NRF_LOG_INFO("ERASING_BONDS \n");
        delete_bonds();
    }
    else
    {
        NRF_LOG_INFO("ADV_SCAN_START");
        adv_scan_start();
    }

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}