Final Project Servo Mechanism

Work Process Detail

1. Servo Motor Selection

• I used a standard SG90 servo motor, which is lightweight and ideal for compact applications like rockets and mechanical triggers.

• Operating voltage: 3V – 6V

• PWM signal control with 0–180° movement range

  

2. Circuit Setup

• Connected the servo signal pin to GPIO 3 on the XIAO ESP32-C3.

• Connected 5V power to the servo using an external power source to avoid overloading the microcontroller.

• GND lines of the ESP32, servo, and power source were all connected to ensure a common reference.
  • [ESP32 GPIO 5] -------> [Servo Signal]
    [3.3V External Power] --> [Servo VCC]
    [Common Ground] ------> [Servo GND] + [ESP32 GND]
    

3. Code Implementation

• Used the ESP32Servo library to generate the required PWM signals.

• The servo was programmed to rotate between defined angles in a loop to simulate mechanical motion like locking/unlocking or latching.

#include <ESP32Servo.h>

Servo myServo;          // create servo object
int servoPin = 5;       // GPIO 3 on ESP32-C3
int angle = 0;          // variable to store the servo position

void setup() {
  Serial.begin(115200);
  myServo.setPeriodHertz(50);       // Standard 50 Hz servo
  myServo.attach(servoPin, 500, 2400); // Min and Max pulse width in µs
}

void loop() {
  // Sweep from 0 to 180
  for (angle = 0; angle <= 180; angle += 1) {
    myServo.write(angle);           
    delay(15);                      
  }

  // Sweep back from 180 to 0
  for (angle = 180; angle >= 0; angle -= 1) {
    myServo.write(angle);           
    delay(15);                      
  }
}

4. Testing & Results

• Tested the servo sweep between 0° and 180°.

• Ensured reliable motion and repeatability.

• Confirmed that the servo can generate enough torque to trigger the mechanical latch for the parachute system.