1. When the external PWM signal is input, the amplitude is 5V, and the recommended PWM frequency is 1K-10KHz. 2. For analog input, you can use the on-board 5V, GND external potentiometer (resistance 10K-100Kohm) to adjust the speed, or you can input (0-5V) analog externally, but it needs to be connected to the GND on the board. 3. For forward and reverse rotation control, the motor needs to stop rotating and then perform forward and reverse operation. It is strictly forbidden to change direction during the rotation of the motor, which will cause damage to the circuit board. In addition, after removing the short-circuit cap, the steering switch can be connected externally for operation. 4. 5V, GND The motherboard comes with a 5V power supply (external power supply can be provided, the current does not exceed 10mA) 5. Speed ​​pulse signal output, the amplitude is 5V, each pulse represents one revolution of the motor. Precautions: 1. There is no fuse in the power supply circuit on the main board. Jianyi has added it himself. Reverse connection of the positive and negative poles of the power supply will cause permanent damage to some chips on the board. 2. There is sampling over-current protection at the output of the motor during normal operation. Because the power and current of the module are very large, please do not artificially short-circuit the module when the module is not working normally. Once the short-circuit, the circuit may be burnt and the tube may burst. Please use small current and low voltage test, after ok, then apply high current and high voltage. Because it is a bare board module, please pay attention to the insulation of the wiring head. It is strictly forbidden that strong voltage contact the board parts. 3. When the operating power of the drive module exceeds 100W or the operating environment exceeds 30