cmd_dcmotor_run Command to run DC motor after setting up cmd_dcmotor_run(h,motor_no,u1) h : Board number, reserved for future use. For this version, any number would do motor_no : ID in which the motor has been connected u1 : Value to sent, range from -255 to 255, for clockwise and anti-clockwise direction Arduino board does not deliver enough power, so it is necessary to use a H-bridge circuit/IC to control the motor. There are several types of H-bridge IC that do not all operate on the same principle. For example, the L298 requires the use of a PWM signal with current sense. The L293 uses two PWM to set the speed and direction. Ready-to-use Shields are also available. Remember that the PWM is 8-bit (0 to 255). The input of the block could accept any value, but it would saturate at +- 255.