Features: UNO-R3 is a new easy-to-use open source controller launched in 2012, with no significant hardware changes compared to UNO-. The major- difference lies in the USB to serial- circuit part. Function: replaced by ATmega16U2 for CH340, means- halving the costs-. Feature description: Open original design circuit diagrams, development software interface for free download, and can also be modified- according to needs. The download program is simple and convenient. It can simply use sensors and various electronic component connections (such as LED lights, buzzers, buttons, photoresistor, etc.) to create various interesting works Using a high-speed microprocessor controller (ATMEGA328), the development interface and environment are very simple and easy to understand, making it very suitable for beginners to learn. Performance- description: Digital-I/O-digital input/output terminal- is 0-13./Analog-I/O-analog input/output terminal- is 0-5, supporting ISP download function. Specifications: Input -voltage: When connected to the computer USB, there is no need for external power supply, and the external power supply is 5V~9V-DC -voltage input. Output voltage: 5V-DC -voltage output and 3.3V-DC -voltage output. Adopting Atmel- Atmega328 microprocessor controller Size:approx 68.5x53.5mm/2.7x2.1in Note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1PC R3 DIP Development Board