Getting two extra LEDs for free (Leonardo only)


As the Arduino Leonardo has only one microcontroller for both interfacing USB and running the sketch the RX and TX LEDs can be controlled by your sketch.

See this example to check how it is done.

As the original purpose of these LEDs is indicating the traffic on the serial line you should not use this trick if your sketch contains Serial.print or Serial.read instructions.


contact: nji(at)gmx.de