Softdevice crashes/disappears after connection speed test

RE: Softdevice crashes/disappears after connection speed test

schef — Mon, 10 Apr 2017 08:49:12 GMT

I have managed to get the sniffer up and running. I will report back after i have some more info.

RE: Softdevice crashes/disappears after connection speed test

FormerMember — Thu, 06 Apr 2017 12:14:01 GMT

I need to summarize what I have understood:

The problems happens when android phone connects and disconnects but nRF52 doesn't get the disconnect event: In this case there should be a BLE_GAP_EVT_TIMEOUT event in the nRF52. Could you double check the behavior using our sniffer?
Airplane mode works also but not disable bluetooth: Does the problem not occur when using airplane mode with Bluetooth enabled?
It disconnects 7 seconds right after turning airplane mode on. It looks like normal disconnect event: In this case the nRF52 should understand that there has been a disconnect through the BLE_GAP_EVT_TIMEOUT event.

RE: Softdevice crashes/disappears after connection speed test

schef — Wed, 05 Apr 2017 12:50:56 GMT

I don't get any timeout event. It disconnects 7 seconds right after turning airplane mode on. It looks like normal disconnect event.

RE: Softdevice crashes/disappears after connection speed test

FormerMember — Wed, 05 Apr 2017 12:33:18 GMT

In the the cases where it doesn't work, the nRF52 doesn't receive the disconnect command from the phone, could you use the sniffer to check if the disconnect command actually was transmitted?

If the nRF52 doesn't receive a disconnect event, it will try to send packets until connection supervision timeout. How does your code handle the timeout event BLE_GAP_EVT_TIMEOUT? Does the nRF52 starts to advertise upon a timeout event?

RE: Softdevice crashes/disappears after connection speed test

schef — Wed, 05 Apr 2017 12:25:55 GMT

Airplane mode works also but not disable bluetooth.

RE: Softdevice crashes/disappears after connection speed test

schef — Wed, 05 Apr 2017 12:15:50 GMT

I have some more folowup: This happens when android phone connects and disconnects but nrf52 doesnt get the disconnect event. So it is in some kind of middle state. After we reboot the android phone the disconnect event occures but not after i turn off the bluetooth on android.

RE: Softdevice crashes/disappears after connection speed test

FormerMember — Tue, 04 Apr 2017 11:59:45 GMT

Yes, that's true. When the chip is not in debug mode and an error is caught by APP_ERROR_CHECK, the chip should reset.

Could you upload your code so that we can test it here? Which version of the SDK and S132 do you use? If you don't want your code to be public, you can create a new support case on myPage from www.nordicsemi.com, upload the code there, and link to this thread.

RE: Softdevice crashes/disappears after connection speed test

schef — Tue, 04 Apr 2017 11:29:49 GMT

I used an example for a starting point which uses APP_ERROR_CHECK(err_code). The app isn't in debug mode any more so i guess that it should restart if anything goes wrong.

RE: Softdevice crashes/disappears after connection speed test

FormerMember — Tue, 04 Apr 2017 11:26:45 GMT

Thanks!

When starting to advertise, do you check the error code returned by sd_ble_gap_adv_start()?

Before starting to advertise, do you wait for BLE_GAP_EVT_DISCONNECT before calling sd_ble_gap_adv_start()?

Do you generally check the error codes?

RE: Softdevice crashes/disappears after connection speed test

schef — Tue, 04 Apr 2017 11:20:39 GMT

samsung galaxy s6 - 6.0.1 - crashed softdevice on nrf52

RE: Softdevice crashes/disappears after connection speed test

FormerMember — Tue, 04 Apr 2017 10:43:12 GMT

Okay, I see. Which phones and Android version are problematic? And which phones and Android version work fine?

RE: Softdevice crashes/disappears after connection speed test

schef — Tue, 04 Apr 2017 09:16:59 GMT

The android makes 100 connections and immediately after it connects it disconnects. I know that characteristics discovery takes some time also.

On some mobile phones after making this test the device stops to advertise.

RE: Softdevice crashes/disappears after connection speed test

FormerMember — Tue, 04 Apr 2017 09:04:38 GMT

From what I understand, you are measuring the time it takes to connect when a device is advertising.

1) The longer a connection interval is, the longer time it will take for a scanner to pick up the signals. Especially if the scanner is not scanning continuously. It is hard to know if Android is scanning continuously. To create a continuous scanner, you can for example use pc-ble-driver.

2) How does the production code work? Does it disconnect immediately after a connect? And after 100 connections, the devices stop to advertise?