BLE - nRF5340-DK: Unsolicited auto-reconnect by PC

[iotdeveloper]

Hello,

I'm having trouble with BLE communication on the nRF5340-DK

I've implemented data transmission and pairing/bonding (LE type, level 4). When I connect from a PC application to the nRF5340 and enter the pairing key, it works fine.

However, when I close the application, it remains connected to BLE in Windows, and I have to turn off Bluetooth on PC manually. It would be better if closing the PC application also closed the BLE connection and the peripheral device (nRF5340-DK) restarted advertising.

Is this possible, or is it simply a feature of Windows Bluetooth?

Thank you

[Turbo J]

Worse: Its likely your PC/OS configuration. Windows normally closes BTLE connections when no app keeps it open. Some profiles like HID are always connected though.

I've seen this problem on some DELL models, the OS or some 3rd party software refuses to disconnect. Very annoying, and we could not identify the source -or reproduce the problem- here.

[iotdeveloper]

Hello,

I'm currently using a Dell Latitude 5550, and after closing the PC application, I have to turn off Bluetooth using the button in the Windows taskbar. Only then does the BLE connection disconnect, and the peripheral (nRF5340-DK) starts advertising again.

[Turbo J]

Try a fresh install of windows with as little DELL software and drivers as possible. Don't remember if our customer tried that - they are OK with just turning BT off and on again...

You could also try booting Linux (e.g. from USB stick).