Add code to communicate with Hiwonder motors

[jess-moss]

What this does

This PR adds hiwonder.py which enables communication (read/write) with the Hiwonder motors, which will be used in a the next robot, the Moss V1.1. Note: In future iterations, more functions may need to be added to this class.

How it was tested

Tested various setups such as the one below in which I read and write motor positions for two serial bus servos daisy chained together.

from lerobot.common.robot_devices.motors.hiwonder import HiwonderMotorsBus

def main():
    # Only connected to two motors currently.
    motors = {"motor1": (1, 'model_x'), "motor2": (2, 'model_y')}
    hw_bus = HiwonderMotorsBus("/dev/ttyUSB0", motors)
    hw_bus.connect()
    positions = hw_bus.read()

    try:
        while True:
            positions = hw_bus.read()

            # Get current positions for both motors
            motor1_pos = positions["motor1"]
            motor2_pos = positions["motor2"]

            # Check if either motor is at or above the 900 position threshold
            if motor1_pos >= 900 or motor2_pos >= 900:
                print("Threshold reached, stopping...")
                break

            # Increment positions by 5, ensuring they do not exceed 995
            new_motor1_pos = min(motor1_pos + 10, 995)
            new_motor2_pos = min(motor2_pos + 10, 995)

            # Write new positions
            hw_bus.write([new_motor1_pos, new_motor2_pos], ["motor1", "motor2"])
            print(f"Positions {positions}.")
            # Sleep to prevent too rapid updates
            time.sleep(0.003)  # Adjust delay as needed for your application
    finally:
        print(f"Positions {positions}.")
        hw_bus.disconnect()


if __name__ == "__main__":
    main()

Note: @Cadene