ArduinoArduino

void loop() {
  digitalWrite(13, HIGH);
  delay(500);
  digitalWrite(13, LOW);
  delay(500);
}

A simulation of how the part behaves — not a recording of mine. Bench photos go in the evidence below.

1. 01 · Blink→

   Hello, world

   An ATmega328P at 16 MHz with 5 V logic. The first program on any of them is the same one: make the LED on pin 13 blink.

2. 02 · Read→

   See what it sees

   Then read something — a button, a sensor — and print it over serial, so you're looking at the same numbers the board is.

3. 03 · React■

   Close the loop

   Then act on it: when the reading crosses a line, do something. Every prototype after that is a bigger version of this loop.

What I actually did with it

• 01On the bench — the fastest route from idea to blinking LED

[ADD — your first Arduino builds]