2. Download the demo, open arduino\PWM\D1-LED path under the D1-LED.ino. 3. Click Tools -> Port, remember the existing COM, do not need to click this COM (different computers show different COM, remember the existing COM on your computer). 4. Connect the driver board to the computer with a USB cable, then click Tools - > Ports, select uf2 Board for the first connection, and after the upload is complete, connecting again will result in an additional COM port.