Features: Adopt of 16U2 chip, with higher transmission speed and memory function Unique design, Added SDA and SCL interfaces. More stable RESET circuit. Close to the USB interface corner, more convenient to press. Digital I/O Digital input/output terminals range from 0 to 13. Analog I/O Analog input/output terminals range from 0 to 5. Support ISP download function. Input voltage: there is no need for external power supply when connecting the computer USB, and the external power supply is 7V-12V dc voltage input. Output voltage: 5V DC output and 3.3v DC output. Adopts of Atmel 328 microprocessor controller Specifications: Chip: 16U2 Input voltage: 7V-12V DC Output voltage:DC 5V/3.3V Weight: 53g Package includes: 1 x Development Board 1 x USB Cable 1、Adopt of 16U2 chip, with higher transmission speed and memory function 2、Unique design, Added SDA and SCL interfaces. 3、More stable RESET circuit. Close to the USB interface corner, more convenient to press. 4、Digital I/O Digital input/output terminals range from 0 to 13. 5、Analog I/O Analog input/output terminals range from 0 to 5.