I have a need for the Udoo to behave like a USB mouse peripheral for another computer. I thought the Arduino USB Mouse/Keyboard Library (http://arduino.cc/en/Reference/MouseKeyboard) would be an excellent choice for this. There is an example for this library where you use 5 switches to control up, down, left, right, and left_click mouse functions. I am trying to build this example sketch from an Arduino IDE 1.5.5-r2 with patch from an external computer. I removed J18, and was able to compile, upload and successfully run the blink test with an LED. So I know my setup works. Thus the problem must be in the USB side of things, which I guess the Udoo might handle a little bit differently than a regular Arduino. Has anyone build this example on an Udoo? It should be straightforward, but i can not get it detected as a mouse on my computer. Do I need to switch the USB cable from the programming port (CN6) to the other one (CN3)? That did not worked either. Do I have to put in J18 back after programming? I am confused with the whole shared serial communication between the Linux and the Arduino sides in the Udoo. Normally this would not be an issue in a regular Arduino.