One project I made for myself was to to wtite a kernel module that could control the led backlight of my laptop keyboard. I had to first reverse engineer the w

One project I made for myself was to to wtite a kernel module that could control the led backlight of my laptop keyboard. I had to first reverse engineer the windows utility that was written in c# and found out that it used wmi commands. After reading the kernel code for a while I realized there where already some code that implemented HP WMI commands. Using that as a foundation it was quite easy to write my own kernel module that could change the led colors. Then I tried to integrate it with the linux kernel's led API. Since the LEDs where RGB it was a little different to integrate but I managed to find some examples in some playstation joystick driver code. This project was a lot of fun, but I would say that you should be careful not to break your hardware. I have broken devices even from the user space by pushing it beyond it's limits.