LESC example with Android

[Rocky]

I am having trouble getting the experimental ble_app_multirole_lesc example working with Android and nRF Connect. It is working fine in iOS. I am using v12.1.0 of the SDK and the nRF Connect app for both tests.

Does anyone know if LESC is yet supported in Android?

The log output looks as follows:

APP:INFO:LE Secure Connections Example
APP:INFO:Scanning
APP:INFO:Advertising
APP:INFO:PERIPHERAL: connected
APP:INFO:PERIPHERAL: BLE_GAP_EVT_SEC_PARAMS_REQUEST
APP:INFO:PERIPHERAL: BLE_GAP_EVT_LESC_DHKEY_REQUEST
APP:INFO:PERIPHERAL: BLE_GAP_EVT_PASSKEY_DISPLAY: passkey=154940 match_req=1
APP:INFO:Press Button 1 to confirm, Button 2 to reject
APP:INFO:Numeric Match
APP:INFO:PERIPHERAL: BLE_GAP_EVT_AUTH_STATUS: status=0x1 bond=0x1 lv4: 0 kdist_own:0x3a kdist_peer:0xb4
APP:INFO:PERIPHERAL: disconnected, reason 19

[Hung Bui]

LESC works with many Android v6.0 phones. Which phone are you testing with ? Could you profile a sniffer trace ? Disconnected reason 19 means BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION. Seems like it's disconnected from the phone.

[Rocky]

It is a Nexus 5X running Android 6.0.1. I also confirmed that the example works in Windows 10 using nRF Connect. I will try again on Android with a sniffer and report back.

[Rocky]

After further troubleshooting, I am now able to get it to work.

It is not entirely reliable, but I can get it to work after removing bonding keys on both the phone and the DK board. I am also disabling/enabling BLE from Android settings between tests. I am then able to bond using the ... button in the upper right hand corner of the nRF Connect Android app.

To complete the pairing process, I press button #1 on the DK board and accept the bonding prompt in the nRF Connect app. It sometimes immediately disconnects, but the bond is successful and I am able to immediately reconnect.

[Hung Bui]

If you bond using the bluetooth setting on Android what would happen ? It would be interesting to see why it's disconnected when you bond, a sniffer trace could help.

[Hung Bui]

I just realized why you got that when testing with the example. It's simply because the phone automatically disconnect after it finish bonding if you are using Bluetooth setting to bond. It's normal behaviour of the phone. If you want to keep the connection after bonding, you should use an app, nRFConnect for example, to request to bond and then you can have the connection kept after that.