Reconnection to device not working with Android when turning dfu mode on

[albo1337]

Describe the bug When I turn the DFU-mode on a Hardware using Android, I am not able to find the hardware again. The reconnection is not working. On iOS this works, it seems that on Android it doesn't work as expected.

To Reproduce Steps to reproduce the behavior:

1. Connect to one device using connectTo()
2. Write a 0 into the dfu characteristic
3. Now hardware is doing a reboot
4. scan for devices
5. no devices can be found, even though the device can be found using an iOS phone

Expected behavior Device can be found on Android and on iOS

• [ yes] I tried doing the same with a general BLE scanner application (e.g. nRF Connect) and it exhibits the expected behavior as described above

Smartphone / tablet

• Device: Pixel 4 XL, Samsung Galaxy S8
• OS: Android 12, Android 7
• Package version: newest

[albo1337]

This is what I get as soon as I turn DFU mode on:

ConnectionStateUpdate(deviceId: 68:0A:E2:F1:88:B1, connectionState: DeviceConnectionState.disconnected, failure: GenericFailure<ConnectionError>(code: ConnectionError.failedToConnect, message: "Disconnected from MAC='XX:XX:XX:XX:XX:XX' with status 19 (GATT_CONN_TERMINATE_PEER_USER)"))

[jobfeikens]

Are you using NRF DFU? In that case when you use unbonded DFU, the last digit of the device's mac address increments with 1, so it will become B2. The recommended way however is to change the devices dfu advertising name using DFU_OP_SET_ADV_NAME and then scan for a device with that name because you can't see the mac address on iOS.

[albo1337]

Hello @jobfeikens, I have a BGM13S Blue gecko chip in my hardware. so no NRF for me ....

[rohitsangwan01]

@albo1337 in my case , i use this combo

set device to dfu rename with a random string

now that device is advertising in dfu with that random name

and scan for bleDevices , get device with that random name out of it

now you got dfu Device ID , use that to update device

also make sure to store orignal device id , to reconnect after dfu operation

[Taym95]

@albo1337 in my case , i use this combo

set device to dfu rename with a random string

now that device is advertising in dfu with that random name

and scan for bleDevices , get device with that random name out of it

now you got dfu Device ID , use that to update device

also make sure to store orignal device id , to reconnect after dfu operation

Please try this combo, I will close this issue for now because doesn't seem like library issue