two triggers, left and right, are read out. two LEDs (left=red, right=green) are turned on when the respective switch is turned on. The second Arduino file (.ino) switches the the LEDs on only in case one trigger is pressed at a time.
Actually, it's just connecting all the parts and cables. I wanted to test my trigger functionality before using those triggers to drive my stepper motor and this is now kind of the documentation. First Fritzing project.