RE: peripheral device only sends indications on connections in which a new bond is formed (not in connections using an existing bond)

jrowe — Sat, 01 Jul 2023 01:18:26 GMT

yeah. that worked.

RE: peripheral device only sends indications on connections in which a new bond is formed (not in connections using an existing bond)

jrowe — Sat, 01 Jul 2023 00:49:06 GMT

It looks like this might be related to something y'all have already fixed.

It seems related to this post, which is identified as fixed in this post.

In the release notes for 15.3 I see

"- Slave Security Requests received during a pairing or encryption procedure will now be ignored (to align with the BLE specification)."

it looks like the change might be restricted to the sec_info_request_process() function in the security_dispatcher... I might try cherry picking that change to see if it helps.

RE: peripheral device only sends indications on connections in which a new bond is formed (not in connections using an existing bond)

jrowe — Fri, 30 Jun 2023 23:47:05 GMT

I collected some sniffer traces. For the first two I used the nrf52 as the central. I collected one trace of the bonding process and one trace of an attempted measurement after the bonding process.

I repeated this using the nrf connect app as the central device. The measurements come through on the nrf connect app without having to delet the bond.

devzone.nordicsemi.com/.../nrf52_5F00_central_5F00_bonding_5F00_process.pcapng devzone.nordicsemi.com/.../phone_5F00_as_5F00_central_5F00_measurement_5F00_after_5F00_bonding.pcapng devzone.nordicsemi.com/.../nrf52_5F00_central_5F00_bonding_5F00_process.pcapng devzone.nordicsemi.com/.../phone_5F00_as_5F00_central_5F00_bonding_5F00_process.pcapng

The bonding processes look really similar. the only difference I saw was that in the pairing request sent by the app the signature key was set to true, which is not an option using the peer manager.

The connection after the bonding process was kind of different though. For the nrf connect app, it was very simple.

The peripheral sends a security request, the central sends an encryption request, the peripheral response, then the peripheral sends a start encryption request.

With the nrf52 as the central, it is much more complicated. They look similar until the central responds to the LL_START_ENC_REQ twice. Then the peripheral also sends a LL_START_ENC_RSP, then there is a encryption pause request, then they re-do everything and the encryption actually starts.

My guess is that the problem is with the behavior after the bond has been made. I really don't know how to change that though.