BLE shuts off and/or the device stops advertising

RE: BLE shuts off and/or the device stops advertising

MartinBL — Mon, 05 Nov 2018 09:08:27 GMT

That is good news! Thank you for the update.

RE: BLE shuts off and/or the device stops advertising

AlexanderGrath — Mon, 05 Nov 2018 08:57:48 GMT

I figured it out and solved the problem. So for anybody who finds this in the hopes to find an answer:

The problem was caused by many little things. First one, like MartinBL suggested some of the functions produced error codes that did not get checked, doublecheck your code. Especially if you used some BLE examples to create your code, they usually do not check for anything. It depends on how you test but under the "right" conditions almost every part of the BLE connection can fail, you definitely want to handle every single exception.

Second thing: The official Bluetooth connection app and our own app that we used for testing allowed faulty or "dead" BLE connections when rapidly connecting/disconnecting. Without apps running, a BLE connection could be kept active (happened only on Android devices). So it seemed the MCU stopped working but it was actually still connected.

Third issue: Something very specific to my case, long story short: a sensor on the MCU completely freaked out when it was exposed to the vibration of a car engine (when taking the thing with me, to the office, home etc).

RE: BLE shuts off and/or the device stops advertising

MartinBL — Fri, 24 Aug 2018 13:26:14 GMT

Happy to help.

Since your application seems to just carry on as normal, but without BLE, I suspect that there are some Softdevice API calls (prefixed sd_... ) without error checking.

RE: BLE shuts off and/or the device stops advertising

AlexanderGrath — Fri, 24 Aug 2018 13:18:15 GMT

Thanks for the fast response, I'll try all those things out.

As of right now, I don't have sniffer traces, so far I used the nRF Connect app do debug the connection (as of now there were no issues, so the app was enough to test things out).

I'll check the code again and add some error handling where it is missing, thanks for that.

The logger module seems nice, especially as it can store crash information to the flash.

RE: BLE shuts off and/or the device stops advertising

MartinBL — Fri, 24 Aug 2018 12:56:52 GMT

Hi,

Do you use the Logger module to print debug info to a terminal? If so what do you see? If not I advise you to implement it.

Do you check the return codes of all your function calls? If not, the typical way of doing it is e.g.:

uint32_t err_code = ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
APP_ERROR_CHECK(err_code);

Can you provide sniffer traces? If you have an extra Nordic dev kit to spare you can use our nRF Bluetooth Sniffer.