nRF Connect App reconnect the BLE fail, when reopen the BLE of the Phone

[ken.oujingxue]

Hi 

I test nRF5_SDK_17.1.0_ddde560\examples\ble_peripheral\ble_app_hrs_freertos on the nRF52840-DK.

and use the nRF connect App to connect to the BLE.

Follow the steps below to test.

1. use nRF connect APP to connect the BLE

2. turn off the BLE of the Phone

3. turn on the BLE of the Phone

4. use nRF connect APP to reconnect the BLE

The BLE connection won't work unless you search for it again.

What causes this? 

But it's ok only on android version 13.

[Einar Thorsrud]

Hi,

Yes, that is how nRF Connect for mobile behaves on iOS. When Bluetooth is toggled off and on again, it will no longer show the device it was connected to before, and the device list will be empty, requiring a new scan.

(There are quite a few differences between nRF Connect for iOS and Android, and most of the functional differences are related to differences in the Bluetooth API's on iOS and Android, where the application has access to more information and operations on Android than on iOS).

[ken.oujingxue]

Hi 

Thanks for your quick reply.

Only considering Android smartphones, nRF Connect APP.
For Apollo BLE platform, reopen the phone's BLE, and BLE reconnect is success.

And for nordic platform, I found the reconnect success only on Android version 13

[Einar Thorsrud]

Hi,

I see. I did not have many Android phones to test with, but I was not able to reproduce this using nRF Connect on Android 9.

Can you elaborate on which nRF Connect version you are using, and which Android version? Also, in case I misunderstood something, perhaps you can share details or a video of how to reproduce?

[ken.oujingxue]

Hi

For the test video, the android version is 9, and the nRF Connect version is 4.26.0

[ken.oujingxue]

The test video for the Apollo BLE

[Einar Thorsrud]

Hi,

Thank you for the videos. Which exact phone are you using? 

As mentioned I have not been able to reproduce this on my end, but I have forwarded it to our app developers so that they can have a look.

[ken.oujingxue]

Hi, 
For the test video, the phone is Honor 7X.

And I tested two Samsung phones, which automatically re-searched Bluetooth when they turned on Bluetooth, and did not reproduce the issure.