🛠 Bouton et console série sur la GIGA R1 WiFi

Objectives

Read a numeric input, debounce it properly, and communicate with the native serial port of the GIGA R1 WiFi (available as soon as it is connected to the USB-C USB0 port, without a USB-to-serial converter). You will also learn the golden rule of pins: 3.3 V logic, never a 5 V signal, and INPUT_PULLUP to avoid wiring to VCC.

Hardware

• Arduino GIGA R1 WiFi board + USB-C cable
• 1 push button between pin 6 and GND (no external resistor needed: we use the internal pull-up)
• Optional: 1 LED + 330 Ω on pin 5 to visually confirm the press

Complete code

// GIGA R1 WiFi — bouton + console série avec anti-rebond
const int BTN_PIN  = 6;    // bouton vers GND, pull-up interne
const int LED_PIN  = 5;    // LED + 330 ohms vers GND

volatile unsigned long appuis = 0;
int etatPrecedent = HIGH;
unsigned long dernierChangement = 0;
const unsigned long ANTI_REBOND = 30;   // ms

void setup {
  Serial.begin(115200);          // port série natif sur USB-C (USB0)
  while (!Serial) {}             // attend l'ouverture du moniteur (USB natif)
  pinMode(BTN_PIN, INPUT_PULLUP);  // 3.3 V logic — jamais de signal 5 V
  pinMode(LED_PIN, OUTPUT);
  Serial.println("GIGA R1 WiFi prete : appuyez sur le bouton broche 6");
}

void loop {
  int etat = digitalRead(BTN_PIN);
  unsigned long maintenant = millis;
  if (etat != etatPrecedent && maintenant - dernierChangement > ANTI_REBOND) {
    dernierChangement = maintenant;
    etatPrecedent = etat;
    if (etat == LOW) {                       // bouton actif a l'etat LOW (pull-up)
      appuis++;
      digitalWrite(LED_PIN, HIGH);
      Serial.print("Appui n#"); Serial.print(appuis);
      Serial.print(" — uptime "); Serial.print(maintenant / 1000); Serial.println(" s");
    } else {
      digitalWrite(LED_PIN, LOW);
    }
  }
}

Expected verification

Open the serial monitor at 115200 baud: the welcome message is displayed. Each press prints a line like “Press n#1 — uptime 12 s” etc., without spurious duplicates (the 30 ms debounce does its job). The indicator LED lights up during the press.

Common errors

• The serial monitor remains empty: with native USB, the while (!Serial) waits for the monitor to open; if you run the sketch without the monitor, it runs in a waiting state — this is intended. Reconnect or open the monitor.
• Button wired to 3.3 V without pull-down: this also works, but you then need INPUT_PULLDOWN or an external resistor; the pull-up + GND schematic is the simplest.
• Presses counted multiple times: debounce missing or too short; increase ANTI_REBOND to 50 ms.
• Inconsistent speed: the native serial port ignores the actual baud rate, but keep 115200 on both sides to avoid surprises with other tools.