Week 12: Networking and Communications

This week, we worked on sending a message between two projects. We attempted to make my mouse control the music generator, but it didn’t work as expected.

For my independent project, I used a controller to operate a servo motor. First, we attached an antenna to the Xiao ESP C6. I encountered difficulties converting the Arduino RP2040 to the ESP C6 as it required a different library file. With the assistance of ChatGPT, I searched for "servo control with PWM" to resolve the issue.

Controller Code

import RPi.GPIO as GPIO
import time

# Pin configuration
servo_pin = 11  # Replace with the actual pin connected to the servo motor

# Setup GPIO
GPIO.setmode(GPIO.BOARD)  # Use physical pin numbering
GPIO.setup(servo_pin, GPIO.OUT)

# Setup PWM
frequency = 50  # Typical servo motors use a 50 Hz frequency
pwm = GPIO.PWM(servo_pin, frequency)
pwm.start(0)  # Start PWM with 0% duty cycle

# Helper function to set angle
def set_servo_angle(angle):
    """
    Sets the servo to the specified angle.
    :param angle: The desired angle (0 to 180 degrees)
    """
    duty_cycle = 2 + (angle / 18)  # Map 0-180 degrees to 2-12% duty cycle
    pwm.ChangeDutyCycle(duty_cycle)
    time.sleep(0.5)  # Allow the servo to reach the position
    pwm.ChangeDutyCycle(0)  # Stop sending signal to prevent jittering

try:
    while True:
        # Move servo to 0 degrees
        print("Moving to 0 degrees")
        set_servo_angle(0)

        # Move servo to 90 degrees
        print("Moving to 90 degrees")
        set_servo_angle(90)

        # Move servo to 180 degrees
        print("Moving to 180 degrees")
        set_servo_angle(180)

except KeyboardInterrupt:
    print("Stopping program")

finally:
    pwm.stop()  # Stop PWM
    GPIO.cleanup()  # Clean up GPIO
            

Motor Code

const int servoPin = A1; // Pin A1 connected to the servo signal wire

// Function to write an angle to the servo motor
void writeServoAngle(int angle) {
  // Convert angle (0-180) to microseconds (1000-2000)
  int pulseWidth = map(angle, 0, 180, 1000, 2000);
  // Send the PWM signal
  digitalWrite(servoPin, HIGH);
  delayMicroseconds(pulseWidth); // HIGH pulse duration
  digitalWrite(servoPin, LOW);
  delay(20 - (pulseWidth / 1000)); // Rest of the 20ms period
}

void setup() {
  pinMode(servoPin, OUTPUT);
}

void loop() {
  // Sweep the servo from 0 to 180 degrees
  for (int angle = 0; angle <= 180; angle += 10) {
    writeServoAngle(angle);
    delay(500); // Wait for servo to reach position
  }

  // Sweep the servo from 180 to 0 degrees
  for (int angle = 180; angle >= 0; angle -= 10) {
    writeServoAngle(angle);
    delay(500); // Wait for servo to reach position
  }
}