In my appliance I'm using the 'official' UDOO 15" touch screen. It doesn't have to be on all the time, especially at night. At the moment I use a timer switch to remove power completely from the board, but I rather have a software solution where I can turn off the screen and keep the board powered. My application isn't running under X, so it is completely standalone. It is written in Java, and minimizing native code would be nice.
I have a 7 inch touch screen and I too would like to turn it off to save power on the robot. Is there a way to programmatically do that using the UDOObuntu image?
There is a kernel module, that we haven't tested it actually, called backlight. It should manage the GPIO of backlight (GPIO 1,4). It's already inside the kernel. I suggest you to google it.
On the Yocto version it can be done by: echo 1 > /sys/class/graphics/fb0/blank echo 0 > /sys/class/graphics/fb0/blank
