In reply to Simon Fels (sorry for the long delay - I put the keyboards aside to focus on other things).
The "Apple Wireless Keyboard" are model A1016 105-key, including a numeric keypad.
Issue still affects 16.04.
From 16.04 attaching a bluetoothd debug log whilst trying to pair with the A1016. It reflects using
tj@T300CHI:~$ bluetoothctl
[NEW] Controller 34:02:86:FC:AD:59 T300CHI [default]
[NEW] Device 00:0A:95:44:37:11 Apple Wireless Keyboard
[NEW] Device 1C:B7:2C:04:C7:FE ASUS T300CHI DOCKING
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 34:02:86:FC:AD:59 Discovering: yes
[NEW] Device 00:1F:3A:E0:0A:AF hephaestion.lan.iam.tj
[CHG] Device 00:0A:95:44:37:11 LegacyPairing: yes
[CHG] Device 00:0A:95:44:37:11 RSSI: -43
[bluetooth]# pair 00:0A:95:44:37:11
Attempting to pair with 00:0A:95:44:37:11
[agent] PIN code: 412054
Failed to pair: org.bluez.Error.ConnectionAttemptFailed
[CHG] Device 00:1F:3A:E0:0A:AF RSSI: -66
Notice that the "[agent] PIN code: 412054" message doesn't appear until I press the A1016 keyboard's Enter key once. I then type the prompted PIN followed by Enter on the A1016 keyboard.
Sometimes I get three prompts to enter PIN codes (each PIN different) before it fails.
In reply to Simon Fels (sorry for the long delay - I put the keyboards aside to focus on other things).
The "Apple Wireless Keyboard" are model A1016 105-key, including a numeric keypad.
Issue still affects 16.04.
From 16.04 attaching a bluetoothd debug log whilst trying to pair with the A1016. It reflects using
tj@T300CHI:~$ bluetoothctl lan.iam. tj Error.Connectio nAttemptFailed
[NEW] Controller 34:02:86:FC:AD:59 T300CHI [default]
[NEW] Device 00:0A:95:44:37:11 Apple Wireless Keyboard
[NEW] Device 1C:B7:2C:04:C7:FE ASUS T300CHI DOCKING
[bluetooth]# agent on
Agent registered
[bluetooth]# default-agent
Default agent request successful
[bluetooth]# scan on
Discovery started
[CHG] Controller 34:02:86:FC:AD:59 Discovering: yes
[NEW] Device 00:1F:3A:E0:0A:AF hephaestion.
[CHG] Device 00:0A:95:44:37:11 LegacyPairing: yes
[CHG] Device 00:0A:95:44:37:11 RSSI: -43
[bluetooth]# pair 00:0A:95:44:37:11
Attempting to pair with 00:0A:95:44:37:11
[agent] PIN code: 412054
Failed to pair: org.bluez.
[CHG] Device 00:1F:3A:E0:0A:AF RSSI: -66
Notice that the "[agent] PIN code: 412054" message doesn't appear until I press the A1016 keyboard's Enter key once. I then type the prompted PIN followed by Enter on the A1016 keyboard.
Sometimes I get three prompts to enter PIN codes (each PIN different) before it fails.