ble_app_uart_c central sometimes not discovering service from peripheral

[SaiTeja]

Hello, I configured nrf52832 as central. I am using ble_app_uart_c example to set the IC as central. And esp32 module is my peripheral. I am able to establish connection and achieved bidirectional communication.

But Sometimes, my central is not discovering the service. BLE_GAP_EVT_CONNECTED event is being invoked and central is connecting to peripheral device, but after that db_disc_handler() is not being called for service discovery.

What might be the reason? Please help me in this regard.

Thank you.

[endnode]

Get a BLE sniffer trace and analyze what low-level (G)ATT commands db_discovery module uses. It might be either bug in it or you supply wrong parameters somewhere or there is good service discovery just your app somehow misses the event from bd_discovery module. Btw. workaround is simply: don't use that module but write your service discovery sequence. This is especially recommended if you do something super simple like looking for single custom service UUID (and some further characteristics under it).

[SaiTeja]

I think nrf sniffer is available for only nrf51 application, but I am using NRF52832 and ESP32 as central and peripheral respectively. What is the better way for debugging my application.

[endnode]

Not really. If you talk about Nordic BLE sniffer FW then it works on nRF51 and nRF52 DK boards and can analyze any BLE communication which uses standard 1Mbps air speed. However if your devices are using long range (modulated PHY at 500 or 125kbps) or higher speed (2Mbps) then you would need some more expensive radio (BLE) network analyzer which can do that (like the one from Teledyne Lecroy or Ellisys). But my feeling is that you will be perfectly fine with any BLE 4.0/4.1 sniffer;)

[Hung Bui]

There is this issue with db_discovery module in current SDK. Could you try to apply the work around and check if that helps ?