[nRF Connect SDK]Force to make pairing(bonding)

[Tim Hwang]

Target nRF52832(nrf52dk_nrf52832)
SDK NCS v2.0.0

I'm testing NCS 2.0 with Android 12.

Making pairing with Android, I call two API when connected.

bt_set_bondable(true);
bt_conn_set_security(conn, BT_SECURITY_L4);

It worked well so far (under Android 11)

BTW Android 12 make trouble security level 1 error.


[log]
00> HS connected
00> HS Connected 4A:B4:CA:22:85:2D (random)
00> Connection parameters updated.
00> interval: 6, latency: 0, timeout: 500
00> Conn params updated: interval 7 ms, latency 0, timeout: 5000 ms
00> Security failed: 4A:B4:CA:22:85:2D (random) level 1 err 2
00> Disconnected: 4A:B4:CA:22:85:2D (random) (reason 34)

Can I have another option to make pairing automatically?

[Tim Hwang]

BT_HCI_2022_0913_150734.zip

Here is snoop log file pf 13Sep2022_B.

For air log, this issue about making pairing so that we don't use stored LTK at that time, I think.
Or please let me know.

[Kenneth]

My suggestion here is to keep experimenting until you find something that works, e.g. for instance try different security level when bonding does it have an effect, don't initiate security request from the peripheral (it should not be necessary if you for instance set that the charactereritics to require a security level, then it should be initiated by the central in any case), go back to a normal ncs example and check if those fail as-is, compare with your project. 

Once you find something that works it will be easier to understand what is causing the issue hopefully.

Kenneth

[Tim Hwang]

BT_HCI_2022_0915_120103.zip

Here is log that does not initiate from peripheral but from Android with sample "\NCS200\v2.0.0\nrf\samples\bluetooth\peripheral_uart" (with CONFIG_BT_GATT_AUTO_SEC_REQ enabled)

It also failed at first pairing request.
Second pairing request worked well.

We need your opinion. We also made case MTK (MediaTek, Android vendor) and wait for their reply.

[Kenneth]

All problems I have seen in the past with Android phones have been related to a security request is being sent from the peripheral to the phone on the first (or early) connection event after connection is established. So if you have a problem, then try disable the security request and run the test again.

Kenneth

[Tim Hwang]

Hello.

Here is my test sequence.

sample: "\NCS200\v2.0.0\nrf\samples\bluetooth\peripheral_uart" (No modification)
(Sample does not include security request)
Test Steps.
1. Remove bonding both Android and Nordic BLE
2. Android 12 scan BLE with Nordic app.
3. select "Bond" from found list

Result
1. First bonding try: failed
2. check failure log in RTTviewer.
3. Second bonding try: success

BT_HCI_2022_0915_120103.zip


BTW, I also found similar case with no solution.

 RE: Android v12 and Pixel phone connection problem

We could see this issue with Pixel Android 12 too.
If you need Android 12 sample for test, please let me know.

[Kenneth]

What phone(s) are you using here?
https://en.wikipedia.org/wiki/Google_Pixel

Best regards,
Kenneth

[Tim Hwang]

All is Android 12.
First is Pixel 3 XL.
Second is MTK solution.
Third will be Qualcomm solution.(It is being prepared in assembly line. Test can be available by end of this week).

Bluebird is also Android handset manufacture, and We're developing & selling Android handset as well as Nordic BLE product.