Not receiving tx notification (NUS service) from second peripheral.

RE: Not receiving tx notification (NUS service) from second peripheral.

ovrebekk — Thu, 29 Aug 2019 12:35:34 GMT

Good to hear you found the issue. I will close the case then 🙂

RE: Not receiving tx notification (NUS service) from second peripheral.

tinytrex — Wed, 28 Aug 2019 18:27:34 GMT

Found the issue. A global variable was being updated undesirably. This was supposed to be updated once upon BLE_NUS_C_EVT_DISCOVERY_COMPLETE event. However I was updating it outside of it so for every handler callback this was being updated. Now I see the data from both the NUS peripherals.

RE: Not receiving tx notification (NUS service) from second peripheral.

tinytrex — Wed, 28 Aug 2019 12:50:39 GMT

I assume the service handler must be invoked from the soft device whenever there is an incoming data from the peripheral. It might be that connection handle of the peripheral is being affected somehow. I am not sure. I am posting my source code. I have removed few parts of the code which are irrelevant just for better readability. devzone.nordicsemi.com/.../2746.main.c

RE: Not receiving tx notification (NUS service) from second peripheral.

tinytrex — Wed, 28 Aug 2019 09:10:15 GMT

Yes, I confirmed BLE_NUS_C_EVT_DISCOVERY_COMPLETE and ble_nus_c_tx_notif_enable(p_ble_nus_c) is successful for both the peripherals. Status is returned as NRF_SUCCESS.

RE: Not receiving tx notification (NUS service) from second peripheral.

ovrebekk — Wed, 28 Aug 2019 07:27:12 GMT

If notifications are not coming through it could be because they are not enabled by the client.

Have you checked whether or not the BLE_NUS_C_EVT_DISCOVERY_COMPLETE event occurs for both peripherals, and whether or not the call to ble_nus_c_tx_notif_enable(p_ble_nus_c) is successful for both of them?

Best regards
Torbjørn

RE: Not receiving tx notification (NUS service) from second peripheral.

tinytrex — Tue, 27 Aug 2019 10:14:43 GMT

The order of the peripherals doesn't matter. It's always the second connection that doesn't work and when I say it doesn't work I mean that I cannot see the streaming NUS data from the second connection. The connection is however alive because I can see the Battery service notification coming regularly from the second peripheral.

RE: Not receiving tx notification (NUS service) from second peripheral.

tinytrex — Tue, 27 Aug 2019 09:47:47 GMT

Hi Torbjørn, I tried debugging the peripherals but I have no clue. I can actually connect the two peripherals to the nRF Connect app (Android) and I can see the data streaming from both the peripherals in the logs. Both peripherals are identical (My peripheral is an Adafruit Feather nRF52832 Bluefruit LE device ... two of them running same code ... only difference is the hardcoded sensor Id which I am using to distinguish the data from the sensors).

RE: Not receiving tx notification (NUS service) from second peripheral.

ovrebekk — Tue, 27 Aug 2019 08:32:47 GMT

Just let me know when you have more results to share.

Did you try to reverse the order of connection, to see if it is always the second connection that doesn't work, or if it follows the peripheral?

Best regards
Torbjørn

RE: Not receiving tx notification (NUS service) from second peripheral.

tinytrex — Mon, 26 Aug 2019 14:42:02 GMT

Ahh nevermind. The issue seems to be in the peripheral. I replaced the second peripheral with a ESP32 with NUS based example application running and I can distinctly see the data streaming from the two peripheral. I am still investigating the issue why the data from second peripheral is not being received. I will update the findings later.