Device Connection count changes

[Venkat RAM]

Hai, I want to connect central to a single  peripheral   and after certain operations, I want to connect central to more peripherals

1. I tried with,

                          #define NRF_SDH_BLE_CENTRAL_LINK_COUNT 1

                           and after some operations, I had changed  to

                           #define NRF_SDH_BLE_CENTRAL_LINK_COUNT 8

                          but  my device (central) connecting to a single peripheral only not with many periphral

         2. even i tried with

                          #define NRF_SDH_BLE_CENTRAL_LINK_COUNT 8

                           BLE_LBS_C_ARRAY_DEF(m_lbs_c, NRF_SDH_BLE_CENTRAL_LINK_COUNT); 
                           BLE_DB_DISCOVERY_ARRAY_DEF(m_db_disc, NRF_SDH_BLE_CENTRAL_LINK_COUNT); 
                           NRF_BLE_SCAN_DEF(m_scan); 
                           NRF_BLE_GQ_DEF(m_ble_gatt_queue, NRF_SDH_BLE_CENTRAL_LINK_COUNT,NRF_BLE_GQ_QUEUE_SIZE);

and after some operations, I had changed  to

                          #define NRF_SDH_BLE_CENTRAL_LINK_COUNT 8

                          BLE_LBS_C_ARRAY_DEF(m_lbs_c, NRF_SDH_BLE_CENTRAL_LINK_COUNT); 
                          BLE_DB_DISCOVERY_ARRAY_DEF(m_db_disc, NRF_SDH_BLE_CENTRAL_LINK_COUNT); 
                          NRF_BLE_SCAN_DEF(m_scan); 
                          NRF_BLE_GQ_DEF(m_ble_gatt_queue, NRF_SDH_BLE_CENTRAL_LINK_COUNT,NRF_BLE_GQ_QUEUE_SIZE);

But  i getting error  like, " Initializer element is not a constant"

 Kindly help me, thank you

[Sigurd]

Hi,

What SDK version are you using ? What example are you testing? Is it ble_app_multilink_central?

You should set NRF_SDH_BLE_CENTRAL_LINK_COUNT to the max number of devices you want to connect to at the same time. 

If you don't want to connect to a new device right after connecting to the first device, you need make sure that you don't resume scanning in the handling of the BLE_GAP_EVT_CONNECTED event in ble_evt_handler().

 

and after certain operations, I want to connect central to more peripherals

 Then after certain operations, you call scan_start(). You can check how many devices you are connect to with ble_conn_state_central_conn_count().

[Venkat RAM]

Hai Sigurd,
 Yes, I am using ble_app_multilink_central fro testing with 16.X.X  SDK along with PCA10056

my  need was my central connect with a single peripheral, and after some operation, my sensor  need to connect with multiple peripheral (which is 8 links),

The function ble_conn_state_central_conn_count() returns the count of link with peripherals, kindly help me

Thanks in advance

[Venkat RAM]

Hai Sigurd, the operations are just saving application data to my FDS via a custom mobile app(Using Bluetooth  in mobile) and after storing the application data  I want to connect with multiple links

Here, my Conditional case only after storing the application data I should connect with multiple device and While writing the application data in fds, I want to connect with a single device, till now I can't do It kindly help me

[Sigurd]

Venkat RAM said:

and after storing the application data  I want to connect with multiple links

 Then maybe you can use the event FDS_EVT_WRITE  in the the registered FDS event handler function to start the scanning again.

[Venkat RAM]

Yes, I am using that same event FDS_EVT_WRITE  and start scan again but now how can I change the  no of count link, 

I had already  given as

// <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 1
#endif  

in my sdk_config and

BLE_LBS_C_ARRAY_DEF(m_lbs_c, NRF_SDH_BLE_CENTRAL_LINK_COUNT); /**< LED button client instances. */

BLE_DB_DISCOVERY_ARRAY_DEF(m_db_disc, NRF_SDH_BLE_CENTRAL_LINK_COUNT); /**< Database discovery module instances. */
NRF_BLE_SCAN_DEF(m_scan); /**< Scanning Module instance. */
NRF_BLE_GQ_DEF(m_ble_gatt_queue, /**< BLE GATT Queue instance. */
NRF_SDH_BLE_CENTRAL_LINK_COUNT,
NRF_BLE_GQ_QUEUE_SIZE);  

in my main file

now after using the event FDS_EVT_WRITE and scan again ,i dont now how to change the Maximum number of central links. again

[Sigurd]

Hi,

Just keep the NRF_SDH_BLE_CENTRAL_LINK_COUNT at 8. If you plan to connect to 8 devices, then you should set this define to 8 from the start.

[Venkat RAM]

Hai Sigurd, I will explain my bug in detail

My Nrf52840 should connect with a maximum of only one device and  through the one device I will; write some data in FDS and only after the success message from the FDS write operation my nrf52840device able to connect with 8 peripheral  devices 

Kindly note Before the FDS success message my device wants to connect with a single device and ONLY after the fds Success message my device wants to connect with multiple(8) device 

[Sigurd]

Hi,

Venkat RAM said:

Kindly note Before the FDS success message my device wants to connect with a single device and ONLY after the fds Success message my device wants to connect with multiple(8) device 

Yes, I understand, just make sure that you don't start the BLE scanning again when you connect the first device. Only start the scanning again when you get the FDS success message.