If external power supply is required, just connect the + level of the external power supply to the position of 5V, GND connects to the negative terminal. (Support 3.3 - 6V power supply). Remember that when connecting the external power supply, you cannot access USB, USB and external power supply can only choose one. Enter the download mode: Hold down the BOOT button of the ESP32C3, press the RESET button, release the RESET button, and then release the BOOT button. Then the ESP32C3 will enter the download mode. (Each connection needs to re-enter the download mode, sometimes press once, the port instability will be disconnected, you can judge by the port identification sound) Colour:Black Material:PCB Package Contents: 1 * Development Board 2 * pin (Pin color is random and cannot be specified.) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.