🛠 Piloter un micro-servo avec la PWM du GIGA R1

Objectives

Master PWM (Pulse Width Modulation) output to control an angle micro-servo. You will learn how to use the Arduino core Servo library, correctly power an external load, and respect the 3.3 V logic of the GIGA R1 (76 GPIO pins available on the board).

Hardware

• 1 Arduino GIGA R1 WiFi board
• 1 SG90-type micro-servo
• 1 dedicated external 5 V power supply (batteries or regulator) — do not power the servo from the board
• Jumper wires, USB-C cable

Complete code

// GIGA R1 WiFi — balayage de micro-servo avec la bibliotheque Servo
#include <Arduino.h>
#include <Servo.h>

const int BROCHE_SERVO = D9;  // broche PWM de la sérigraphie
Servo monServo;
int angle = 0;
int sens = 1;

void setup {
  Serial.begin(115200);
  monServo.attach(BROCHE_SERVO);   // attache la broche au signal servo
  monServo.write(0);
}

void loop {
  angle += sens * 5;               // balle 0 -> 180 -> 0
  if (angle >= 180) sens = -1;
  if (angle <= 0)   sens = 1;
  monServo.write(angle);
  Serial.printf("angle = %d\n", angle);
  delay(30);
}

Wiring: orange wire (signal) to D9, red wire to external +5 V, brown wire to external GND, and external GND connected to a board GND (common ground is mandatory).

Expected verification

The servo sweeps back and forth regularly from 0° to 180°. The Serial Monitor (115200 baud) displays the current angle. The movement is smooth, without jitter or saturation whining.

Common errors

• Powering the servo from the board's 5 V pin: voltage drops, restarts, or even damage to the regulator; the GIGA accepts 6–24 V on VIN, but the servo must have its own power source.
• Forgetting the common ground between the external power supply and the board: the servo vibrates or does not respond.
• Non-PWM compatible pin: not all pins generate PWM; the exact number of PWM pins on the Arduino side is not published in the retrieved pages.
• 3.3 V / 5 V confusion: the control signal is accepted by the servo, but never feed 5 V back to the pin.