How Slave Gets Encryption Error Information

[somaker]

I created a HID Server and paired it with the phone.

When I use

NimBLEDevice::deleteAllBonds();

to delete the binding information, the phone can still connect to the server, but it will be disconnected immediately. The ondisconnect event triggers, but I don't know how to get the reason for the disconnection. Through sniffer, we know that the reason is "PIN or Key Missing" We can't trigger a re-pair unless we choose to ignore this hid device on the phone. My question is, is it possible to get the error message and even request re-pairing from the slave side?

BLE Sniffer:

Bluetooth Low Energy Link Layer Access Address: 0xaf9aabed [Master Address: 67:86:ee:88:51:3a (67:86:ee:88:51:3a)] [Slave Address: Espressi_56:db:7a (a0:76:4e:56:db:7a)] Data Header: 0x0317 Control Opcode: LL_REJECT_IND_EXT (0x11) Reject Opcode: LL_ENC_REQ (0x03) Error Code: PIN or Key Missing (0x06) CRC: 0x8e0ec0

Thank you!

[h2zero]

If the error only comes after the disconnection then it would be too late to trigger the pairing anyway. The client needs to delete the bond on it's side as well. I will look to change the callback in the future to provide the reason code.