BLE does not connect to a specific phone

RE: BLE does not connect to a specific phone

Vahidreza — Tue, 18 Oct 2022 15:58:35 GMT

Thank you very much dear Hung.

I added that delete_bonds() function in the dongle startup function and the issue is solved now.

RE: BLE does not connect to a specific phone

Hung Bui — Tue, 18 Oct 2022 07:59:07 GMT

Hi Vahidreza,

From what I can see what happened was that the central tried to encrypt the link because it has been bonded with the phone before but the phone has removed the bond information. The central reject the connection after the phone reject the encryption request.

The problem with the dongle is that it's not possible to completely erase its flash unless you connect a debugger to it. The dongle is not designed as a development board.

If you want to erase the bond information , what you need to do is to make a feature on your firmware to erase bond information. It's similar to this function in ble_app_hrs:

On the sniffer trace where there was no problem, the central didn't try to re-encrypt the link because they has not bonded before.

RE: BLE does not connect to a specific phone

Vahidreza — Mon, 17 Oct 2022 14:04:43 GMT

Hi Hung

Sorry for the mistake I made. I sent you another sniffing result. I also included a result in which the connection is not terminated just in case it might be helpful.

drive.google.com/.../view

[quote userid="2121" url="~/f/nordic-q-a/91643/ble-does-not-connect-to-a-specific-phone/390912"] I assume you are using the dongle as advertiser/peripheral and the phone as central ? [/quote]

No. The dongle is central and the phone is peripheral/advertiser.

RE: BLE does not connect to a specific phone

Hung Bui — Mon, 17 Oct 2022 08:01:23 GMT

Hi Vahidreza,

It doesn't seems that you have selected the dongle to follow the connection.
You should select the advertiser in the drop down menu like this:

After that the sniffer will follow only one single advertiser , only after that it can follow the connection. I assume you are using the dongle as advertiser/peripheral and the phone as central ?

RE: BLE does not connect to a specific phone

Vahidreza — Sat, 15 Oct 2022 14:26:16 GMT

Hello dear Hung

Sorry for the late answer. There is the sniffing result: drive.google.com/.../view

This issue also was occurred on another dongle with an iPhone but it was only once. One of my fiends is also facing this issue with an Android Smart Phone and another dongle sometimes. But I have this issue all the time with this dongle and my Phone as I described in the ticket description.

RE: BLE does not connect to a specific phone

Hung Bui — Tue, 06 Sep 2022 08:21:06 GMT

Hi Vahidreza,

We would need to have a look at the sniffer trace to see what went wrong, specifically on which side terminate the connection.
Please use one of the dongle /DevKit and sniff the connection.