How to get past "link secure failed! error: PM_CONN_SEC_ERROR_DISCONNECT

[Pierre Landau]

I was working with examples/ble_peripheral/ble_app_gls. In the SDK11alpha configuration, I paired the dev board with my Android phone running nRF Toolbox and was able to start to modify the example and do things with the glucose data.

I've worked my changes into SDK11 - the change from device_manager to peer_manager had me starting over all of my work as the main program changed so much. No matter.

The real issue is that now I went into the Android part with the nRF Control Panel, and undid the pairing (since the softdevice on the nRF51 is different, etc.) and now want to re-pair the two devices.

However, in the RTT printout, I see: 0> BLE_GAP_EVT_SEC_PARAMS_REQUEST 0> À link secure failed! error: PM_CONN_SEC_ERROR_DISCONNECT

and on the Android phone, the display shows "bonding..." for awhile, and simultaneous with the second line appearing on RTT, it shows "not bonded".

How best to work around this?

[Pierre Landau]

Several seconds after these, I see: Rcvd Connection Parameter Update Request Rcvd Connection Parameter Update Reesponse (Accepted) but nothing relevant to pairing, and eventually the phone shows "not bonded" while RTT shows "link secure failed! error: PM_CONN_SEC_ERROR_DISCONNECT", which is not particularly informative

[Pierre Landau]

With the help of your FAE (Audun), we were able to work around this by (a) changing SEC_PARAM_MITM to 0, SEC_PARAM_IO_CAPABILITIES to BLE_GAP_IO_CAPS_NONE, and then editing pm_evt_handler to remove the check for MITM.

Nowhere near clear why this manifested in the way it did, but at least we can now move forward.