Too long time to re-connect with a nRF bluetooth device after disconnect

[Richard Yin]

Hi Nordic Team:

We developed a bluetooth device based on the nRF52840/Nordic SDK. We also develop Andriod App to communicate with this device via BLE5.

During the system testing, we found our App on some phones need 8 seconds or more to pair and bond again immediately with the same device after the bond removed by calling the Android native API removeBond().  This time is much longer than the time to pair and bond the device when the App just lunched.

We wondered why the re-connect time is so long. Do you have any idea of this problem?

Best regards

[Kenneth]

Hi,

You may try to check a sniffer log, for instance it may be that the disconnect packet is not sent or not received by the peripheral in some case (e.g. due to interference). In such case the peripheral will maintain in a link until supervisor timeout occurs, which I suspect can be 8 seconds in this case.

Best regards,
Kenneth