NRF52 BLE UART + Proximity

RE: NRF52 BLE UART + Proximity

Siddharth rana — Sat, 15 Jun 2019 20:10:05 GMT

Hi Sunil

Look for saadc example in nrf peripheral it might help you

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Sat, 15 Jun 2019 18:15:19 GMT

Hi Siddharth,

Now i stuck with calculating Battery Voltage Measurement do you have any example or similar code?

RE: NRF52 BLE UART + Proximity

Siddharth rana — Sat, 15 Jun 2019 17:35:29 GMT

Hello Sunil

Regarding the battery voltage measurement u can implement saadc periperperl .

The default config have 1/6 ratio with 0.6 internal reference and 10bit resolution.Follow the reference manual for equation for calculation.

Further u can Implement voltage to percentile conversation with proximity example.

Hope this helps you

RE: NRF52 BLE UART + Proximity

Siddharth rana — Sat, 15 Jun 2019 17:30:52 GMT

Hello Sunil.

If u face problem with connection peer failed .

Then reload the softdevice program with full chip erase and I guess it will solve the problem

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Tue, 04 Dec 2018 05:00:21 GMT

Thank you Bjorn

RE: NRF52 BLE UART + Proximity

bjorn-spockeli — Mon, 26 Nov 2018 09:30:28 GMT

If you receive the BLE_CONN_PARAMS_EVT_FAILED event, then the peripheral will disconnect as the connection parameters required by the master(Central) is incompatible with the parameters required by the slave(peripheral).

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Fri, 23 Nov 2018 14:25:19 GMT

thank you the tutorial. i will see that

I diidn't understand this function in BLE_UART

is there any tutorial or can you explain

static void on_conn_params_evt(ble_conn_params_evt_t * p_evt)
{
    uint32_t err_code;

    if (p_evt->evt_type == BLE_CONN_PARAMS_EVT_FAILED)
    {
        err_code = sd_ble_gap_disconnect(m_conn_handle, BLE_HCI_CONN_INTERVAL_UNACCEPTABLE);
        APP_ERROR_CHECK(err_code);
    }
}


/**@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);
}


/**@brief Function for initializing the Connection Parameters module.
 */
static void conn_params_init(void)
{
    uint32_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_GATT_HANDLE_INVALID;
    cp_init.disconnect_on_fail             = false;
    cp_init.evt_handler                    = on_conn_params_evt;
    cp_init.error_handler                  = conn_params_error_handler;

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

RE: NRF52 BLE UART + Proximity

bjorn-spockeli — Thu, 22 Nov 2018 13:32:07 GMT

Q1: You can measure the RSSI, see S132 SoftDevice v6.1.0: RSSI get sample and sd_ble_gap_rssi_get.

Q2: The proximity example already implements the features you are asking for, i.e alerting the connected devices are too far apart so the the connection is lost.

Q3: Yes, it is possible merge the proximity example with the beacon example, but I guess it would be better to just merge ble_app_uart and ble_app_proximity.

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Thu, 22 Nov 2018 12:07:02 GMT

thank you i got the saadc value. i need to interlink with my code.

is there any simple solution to find the distance between the mobile phone and the DK board

is there any simple function to read the RSSI pin of bluetooth connection. so that i alert the person if the device is in out of range

is it possible to merge both BLE_proximity and BLE_Beacon . because i need to know the distance, range in dBm and out of range need to alert the person. simultaneously it needs to read the sensor data and through it in BLE_UART.

AIM is : NRF + TWI + BLE_UART + proximity + distance + saadc

RE: NRF52 BLE UART + Proximity

bjorn-spockeli — Thu, 22 Nov 2018 10:17:46 GMT

The SAADC of the nRF52 can measure VDD by setting NRF_SAADC_INPUT_VDD as the input. This is an internal connection so you do not have to use one of the GPIOs You can find examples for the nRF52 here.

This eliminates the need for any external protection circuits.

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Thu, 22 Nov 2018 10:01:35 GMT

Hi bjorn,

i got the SAADC values by connecting the P0.02 pin to VDD. if the voltage drop occur this adc value becomes drop. is this correct one or any thing to be change.

if the method that i done is correct. for hardware protection we need add any resistance or any internal protection circuit is there for the pin.?

RE: NRF52 BLE UART + Proximity

bjorn-spockeli — Mon, 19 Nov 2018 15:45:10 GMT

Q1: DCC,DEC1-4 are decoupling pins for the various internal modules

Q2: If the battery voltage is above the maximum VDD of the nRF52, (i.e 3.6V) and stepped down to 3.6 or below, then you need to use an external voltage divider. If it is within the 1.7v- 3.6v, then you can connect VDD to the SAADC internally.

See https://devzone.nordicsemi.com/b/blog/posts/measuring-lithium-battery-voltage-with-nrf52 and https://devzone.nordicsemi.com/f/nordic-q-a/17183/adc-input-voltage---nrf52/66004#66004

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Mon, 19 Nov 2018 15:35:14 GMT

is voltage divider used in any pin connection..?

what does the pin DCC,DEC1,DEC2,DEC3,DEC4 can you explain please.

is there any hardware Voltage divider or any other to do ADC process?

or by internal VDD - SAADC will calculate the battery level..

Actually I need a simple solution sir. I need to calculate the battery level like (0% - 100%) i need to calculate each and every single percentage.

please give a line diagram to connect any external pin connection to read the battery level.

or is there any functions to clearly read the battery level without any external analog pins...?

RE: NRF52 BLE UART + Proximity

bjorn-spockeli — Mon, 19 Nov 2018 14:56:33 GMT

Q1: It uses the ADC, see Proximity Application.

Q2: See the Testing section of Proximity Application for the description of LED indications.

The nRF52 DK Hardware schematics and layout can be found here.

RE: NRF52 BLE UART + Proximity

bjorn-spockeli — Mon, 19 Nov 2018 14:55:17 GMT

See step 24 in Proximity Application

Press and hold Button 2 (erase bonds) for 5 seconds and connect with the first nRF Connect. Observe that the link encryption is OFF ("Security updated, mode:1, level:1") and that no notifications are received.

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Sun, 18 Nov 2018 07:58:24 GMT

i got one more problem that is while pair with device. after some time i did un-pair in mobile phone. and i reconnect with the device but it doesn't pair with phone

in log it shows

<info> app: No Alert.
<info> app: Connected.
<info> peer_manager_handler: Connection security failed: role: Peripheral, conn_handle: 0x0, procedure: Bonding, error: 133
<info> app: Fast advertising.
<info> app: Disconnected.
<info> app: No Alert.
<info> app: Connected.
<info> peer_manager_handler: Connection security failed: role: Peripheral, conn_handle: 0x0, procedure: Bonding, error: 133
<info> app: Fast advertising.
<info> app: Disconnected.

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Sun, 18 Nov 2018 06:27:28 GMT

Hi Bjorn,

I need a clarification in BLE_Proximity. in that I download the code and I connect with Mobile phone. It ask for pair the device. and pair the device.

In app it shows the Battery level and location enable disable option.

1) battery level is measure based on LPCOMP or using ADC pin connection?

2) the proximity output as led 2 ON is this because of RSSI ?

can you please give a brief explanation about this BLE_Proximity.

If the battery level measure due to ADC means shall i get the schematic of the NRF52832 development board. I need a bit clarification about this.

RE: NRF52 BLE UART + Proximity

bjorn-spockeli — Fri, 16 Nov 2018 12:09:04 GMT

HI Sunil,

Q1: There are no internal peripheral that measures VDD on the NRF52. You need to use the ADC to measure VDD. Alternatively, if yo ujust want to know if VDD has fallen below a certain threshold, then you can use the LPCOMP.

Q2: You can use the RSSI to determine of the connected device is close of far away, see S132 SoftDevice v6.1.0: RSSI get sample.

Best regards

Bjørn

RE: NRF52 BLE UART + Proximity

ps_anu — Fri, 16 Nov 2018 07:54:10 GMT

just i want to sense the temperature through the temperature sensor and want to send the data to the uart app

RE: NRF52 BLE UART + Proximity

ps_anu — Fri, 16 Nov 2018 07:39:13 GMT

lm335 ..

YES

undefined reference to `ble_nus_string_send'

Output/ble_app_uart_pca10056_s140 Release/Obj/main.o: In function `nus_data_handler':

RE: NRF52 BLE UART + Proximity

Sunil vignesh — Fri, 16 Nov 2018 07:34:18 GMT

HI saral,

i have few questions:

1. Which temperature sensor are you using?

2. are you get the raw data from sensor using TWI ?

3. what kind of error are you getting?

RE: NRF52 BLE UART + Proximity

ps_anu — Fri, 16 Nov 2018 07:26:48 GMT

hi..... sunil ..

i am using nrf52832 to read the temperature sensor by usin i2c

i try to send the sensor data to mobile ,... i am merging two examples programs uart and twi sensor

it is showing error in nus_data_handler

can you help me how to merge the program and what are the changes i want to do