Makes the 'L' LED (port B5) on Arduino Nano board toggle on and off with signal change (HIGH to LOW) on port D5 or any serial input (UART) on USB, then shares current state ('on' or 'off') as serial ...

prototype: If you move toggle, and led can move direction of move. But not real time. prototype_2: If you move toggle, so led can move direction of move in real time. Problem: First relay is Ok. But ...