I would try to send a serial command, like "1" or "0", from a Rainmeter desktop Icon,"Set Led On" or "Off", to a Arduino pin led or intern pinled 13.
The Rainmeter that i use write in .ini, i don't no if it's possible to let the .ini data comunicate with the arduino .ino data
I just would to press a button on the computer desktop and let the arduino no that the button be'n pushed and set the lights on. Its all in the computer case and the Arduino is connected with Usb port4...
Please Help for my little project!!!