I have a few of the 4" widescreen ones is there a command I can issue in SSH to change the brightness ? couldnt find anything googling and built in Monitor adjustment in Pi Bookworm doesnt seem to work ;( thanks in advance !
You will find some information here: HyperPixel Brightness Control
I don’t think the last post in that thread is fully correct. I would try to turn the brightness off as documented there, and then use PWM on GPIO19. There are tons of examples of using PWM on a Pi GPIO.