Connect Apple Wireless Keyboard to Raspberry Pi 3 in Raspbian

rpi3-bt-keyboard.txt

sudo service bluetooth status  # Verify bluetooth is active.
sudo bluetoothctl              # Lauch bluetooth subshell.
agent on                       # [No idea what this does.]
default-agent                  # [No idea what this does.]
scan on                        # Displays a list of available devices.
pair XX:XX:XX:XX:XX:XX         # This prepares a potential connection, the X's represent your device ID
# A "PIN code" will be displayed, type it on the keyboard and press "enter".
trust XX:XX:XX:XX:XX:XX        # Adds device to trusted devices, this survives reboot.
connect XX:XX:XX:XX:XX:XX      # Connect to the device now.
exit                           # Return to previous shell.