Automation, sensing and robotics • Re: Building a Robot Car with Raspberry Pi 5

Code:

#!/usr/bin/env python3"""Raspberry Pi 5 Robot Car ControllerFor Ackermann Chassis with servo steering and DC motor drive"""import RPi.GPIO as GPIOimport time# GPIO Pin setupSERVO_PIN = 17MOTOR_DIR1 = 23MOTOR_DIR2 = 24MOTOR_PWM = 25# ConstantsSERVO_CENTER = 7.5  # Duty cycle for center position (adjust as needed)SERVO_LEFT = 5.0    # Duty cycle for full leftSERVO_RIGHT = 10.0  # Duty cycle for full rightMOTOR_FREQ = 100    # PWM frequency for motorclass AckermannRobotCar:    def __init__(self):        # Set GPIO mode        GPIO.setmode(GPIO.BCM)        GPIO.setwarnings(False)                # Setup servo pin        GPIO.setup(SERVO_PIN, GPIO.OUT)        self.servo_pwm = GPIO.PWM(SERVO_PIN, 50)  # 50Hz for servo        self.servo_pwm.start(SERVO_CENTER)                # Setup motor pins        GPIO.setup(MOTOR_DIR1, GPIO.OUT)        GPIO.setup(MOTOR_DIR2, GPIO.OUT)        GPIO.setup(MOTOR_PWM, GPIO.OUT)                self.motor_pwm = GPIO.PWM(MOTOR_PWM, MOTOR_FREQ)        self.motor_pwm.start(0)                print("Robot car initialized")            def steer(self, angle):        """        Steer the car. Angle should be between -1.0 (full left) and 1.0 (full right)        """        if angle < -1.0:            angle = -1.0        elif angle > 1.0:            angle = 1.0                    # Convert angle to duty cycle        if angle < 0:            # Left turn            duty_cycle = SERVO_CENTER + angle * (SERVO_CENTER - SERVO_LEFT)        else:            # Right turn            duty_cycle = SERVO_CENTER + angle * (SERVO_RIGHT - SERVO_CENTER)                    self.servo_pwm.ChangeDutyCycle(duty_cycle)        print(f"Steering: {angle:.2f}, PWM: {duty_cycle:.2f}")            def drive(self, speed):        """        Drive the car. Speed should be between -1.0 (full reverse) and 1.0 (full forward)        """        if speed < -1.0:            speed = -1.0        elif speed > 1.0:            speed = 1.0                    # Set direction        if speed >= 0:            GPIO.output(MOTOR_DIR1, GPIO.HIGH)            GPIO.output(MOTOR_DIR2, GPIO.LOW)            pwm_value = abs(speed) * 100        else:            GPIO.output(MOTOR_DIR1, GPIO.LOW)            GPIO.output(MOTOR_DIR2, GPIO.HIGH)            pwm_value = abs(speed) * 100                    self.motor_pwm.ChangeDutyCycle(pwm_value)        print(f"Driving: {speed:.2f}, PWM: {pwm_value:.2f}")            def stop(self):        """Stop the car (both steering and driving)"""        self.steer(0)        self.drive(0)        print("Car stopped")            def cleanup(self):        """Clean up GPIO"""        self.stop()        self.servo_pwm.stop()        self.motor_pwm.stop()        GPIO.cleanup()        print("GPIO cleaned up")        # Example usageif __name__ == "__main__":    car = AckermannRobotCar()        try:        print("Testing car controls...")                # Center the steering        car.steer(0)        time.sleep(1)                # Test left turn        print("Turning left...")        car.steer(-0.5)        time.sleep(1)                # Test right turn        print("Turning right...")        car.steer(0.5)        time.sleep(1)                # Center again        car.steer(0)        time.sleep(1)                # Test driving forward        print("Driving forward...")        car.drive(0.5)        time.sleep(2)                # Test driving backward        print("Driving backward...")        car.drive(-0.5)        time.sleep(2)                # Stop        car.stop()            except KeyboardInterrupt:        print("Program stopped by user")    finally:        car.cleanup()