nRF52 stuck after disconnect from android.

[dc]

Hi,

I am using nRF52 chip with SDK13.0. MTU size 155.

I am connect with device using android phone. After sending 1 byte command device starting to send continuous notification to android phone.

Device is busy to send notification to android phone. meanwhile if I press disconnect button in android (nRF Connect App), device stuck somewhere. I am guessing this happens because I am not getting BLE DISCONNCT event quickly and during that interval also trying to send notification even ble link is break.

Is there any way to know quickly if ble link drop? (without waiting BLE DISCONNECT event)

what is other route cause of device stuck in this situation?

Thanks.

[run_ar]

Might be that android keeps the connection alive. Even though the app is trying to disconnect. Try exiting the app completely and make sure you don't have any other apps that might use the device running. Appart from that you will get a disconnection event when disconnected. A sniffer trace would be helpful.

[dc]

Thanks for Reply! This issue happens even I off android Bluetooth when device continuous sending notification.

[run_ar]

What is the connection supervision timeout in this case? I have seen up to 20 seconds by default on Androind, and that is a long time to wait for the disconnected event.

[dc]

Device side supervision timeout is 4 sec. Android side i am using nRF connect.

[run_ar]

You have to look at the timing event (or use a sniffer to look at the connection request) to see what the supervision timeout is. I don't think the SDK function that checks the connection parameters checks the supervision timeout. Which means the other parameters could be within the desired range while the timeout is huge. As a test you could send the connection parameter update request regardless of peer parameters.