clignotante.ino
The go-to sanity check: the LED on pin 13 blinks at 1 Hz. millis() replaces delay() to keep the loop free. If nothing blinks, suspect the upload or the board selection.
Hardware required
An Arduino Due (AT91SAM3X8E, ARM Cortex-M3 at 84 MHz) connected over USB to its « Programming » port. Caution: 3.3 V logic, never 5 V on the pins. No external component: the onboard user LED is enough.
Wiring
Nothing to wire, the LED sits on pin 13 behind a current-limiting resistor.
How it works
Each loop pass compares millis() with the last change; after 500 ms the pin state flips. In the Arduino IDE, select « Arduino Due (Programming Port) » then Upload; the serial monitor runs at the speed set in the code.
Going further
Vary PERIODE, or add an external LED with a 330 Ω resistor on another pin. Rappel : la LED et toutes les broches de la Due sont en 3,3 V.
clignotante.ino
// Clignotement de la LED integree (broche 13, alias LED_BUILTIN).
const long PERIODE = 500; // ms entre deux changements d'etat
bool etat = false;
unsigned long precedent = 0;
void setup() {
pinMode(LED_BUILTIN, OUTPUT);
Serial.begin(9600);
Serial.println(F("Clignotement demarre"));
}
void loop() {
unsigned long t = millis();
if (t - precedent >= PERIODE) {
precedent = t;
etat = !etat;
digitalWrite(LED_BUILTIN, etat ? HIGH : LOW);
Serial.println(etat ? F("ON") : F("OFF"));
}
}