I have a 7" TFT LCD and I am building my own car head unit but obviously it is vital that it can dim. There are dim buttons on the board and an on/off screen button.
I have tried using:
echo n > /sys/class/backlight/rpi-backlight/brightness/
(Putting in a number between 0 and 255 for n) however I am told that there is no such directory so I tried
and this did not solve the issue.
I also tried to use
ddccontrol except it could not detect any I2C inferfaces.
I am using HDMI interface. I have attached images of my screen, the screen is capable of dimming except I can not figure out how to do this through software.