This is a development and debugging tool, with automatic firmware download, serial communication, JTAG online debugging and other functions. Both interfaces can be supplied with 5V or 3.3V power through the Pin Header, which has strong power compatibility. Simple and convenient to use, only a USB cable can be used to connect with the computer, the computer side can identify the two ports corresponding to the download function and JTAG function. It can be connected with the breakout board using a wire, and the connector can be packaged with two pitches of 2.54mm and 1.27mm. Automatic firmware download and serial communication functions are applicable to ESP8266 and ESP32 platforms. The JTAG online debugging function is available for ESP32 platforms.