Headlight control brightness - opencardev/crankshaft GitHub Wiki
uncomment the file /boot/crankshaft/gpio2kbd.cfg BRIGHTNESSUP
BRIGHTNESSUP 6
Then edit the file /boot/crankshaft/triggerhappy.conf
BRIGHTNESSUP 1 .../brightness.sh set 200
BRIGHTNESSUP 0 .../brightness.sh set 10