How to use an iMac’s bluetooth keyboard and mouse after wiping out MacOS and setting up Ubuntu.

• make sure the keyboard is turned off (e.g. remove batteries)

• enter the `bluetoothctl` shell

  sudo bluetoothctl
  

• power on bluetooth and scan for devices

  bluetoothctl> power on
  bluetoothctl> scan on
  

• turn the keyboard on and keep its power button pressed

• Wait for the keyboard to appear in scanned devices, and copy its MACADDRESS

• issue the following commands

  bluetoothctl> trust MACADDRESS
  bluetoothctl> pair MACADDRESS
  

• wait for a PIN to appear

• release the keyboard’s power button and enter the PIN on the keyboard and press ENTER

The keyboard should now be paired and will automatically pair the next time the system is turned on.

Pairing the mouse uses similar steps.

• turn mouse off
• enter the `bluetoothctl` shell and scan for devices
• turn on the mouse
• wait for mouse to be discovered and note its MACADDRESS
• issue `trust` and `pair` commands