I have accidentally implemented a program that imitates the click of the mouse.
The problem is that now I can´t delete the program because each time that I connect the USB, the computer starts clicking everything and it is not possible to upload a new program.
Can I solve this problem?
Hold the RESET button as you plug the Arduino in and keep it pressed all the time it's plugged into your computer. Load Blink.ino into the IDE and compile it. Press the UPLOAD button in the IDE and move the mouse to somewhere "safe". Release the RESET button.
Do those last three steps in rapid succession and you should be fine.
