SOS message in Morse code

Goal

Send ··· ––– ··· on the LED with exact timings.

Why it matters

Your first encoding of information over time: this is already modulation.

Steps

1. 01Write two functions dot() and dash() lighting the LED for 200 ms / 600 ms.
2. 02Call them in the right order inside loop().
3. 03Add a 1 s pause between each letter.

Next tutorials

• Blink an LED

  Turn an LED on pin 13 on and off every second.

• Two alternating LEDs

  Alternate two LEDs (pins 12 and 13) like a level crossing.

• 5-LED chaser

  Run a light across 5 LEDs using a for loop and an array.

• Blink without delay() (millis)

  Replace delay() with a time comparison based on millis().