controller.py

class MotorsWheels:

    def __init__(
            self, r_wheel_forward=6, r_wheel_backward=13, l_wheel_forward=19, l_wheel_backward=26):
                self.r_wheel_forward = r_wheel_forward
                ...
                GPIO.setmode(GPIO.BCM)
        GPIO.setup(r_wheel_forward, GPIO.OUT)
                GPIO.setup(r_wheel_backward, GPIO.OUT)
                ...
                # Turn all motors off
        GPIO.output(r_wheel_forward, GPIO.LOW)
        GPIO.output(r_wheel_backward, GPIO.LOW)

    def _spin_right_wheel_forward(self):
        GPIO.output(self.r_wheel_forward, GPIO.HIGH)
        GPIO.output(self.r_wheel_backward, GPIO.LOW)

    def _stop_right_wheel(self):
        GPIO.output(self.r_wheel_backward, GPIO.LOW)
        GPIO.output(self.r_wheel_forward, GPIO.LOW)

    def go_fw(self):
        self._spin_left_wheel_forward()
        self._spin_right_wheel_forward()

class ServoCamera:
    CENTER = 40000
    UP_LIMIT = 80000
    DOWN_LIMIT = 30000
    STEP = 5000

    def __init__(self, servo=18, freq=50):
        self.servo = servo
        self.freq = freq
        self.pi = pigpio.pi()

        self.angle = self.CENTER
        self._set_angle()

    def _set_angle(self):
        self.pi.hardware_PWM(self.servo, self.freq, self.angle)

    def up(self):
        if self.angle + self.STEP < self.UP_LIMIT:
            self.angle += self.STEP
            self._set_angle()

    def down(self):
        if self.angle - self.STEP > self.DOWN_LIMIT:
            self.angle -= self.STEP
            self._set_angle()