Specification ATMEGA32U4 running in 5V / 16MHz Support Arduino IDE V1.0.1 Micro USB interface programming on the board Four 10bit ADC pin 12 digital I / O (5 PWM capability) Rx and Tx hardware serial connection Item size: Approx. 2 * 1cm / 0.8 * 0.4in(L * W) Item weight: Approx. 4g / 0.15oz Package size: Approx. 5 * 3.3 cm / 0.2 * 0.1in(L * W ) Description Promicro 5V microcontroller development board has 4 channel 10 bit ADC, 5 PWM pins, 12 DIO, and a hardware serial connection Rx and Tx you are familiar with. Features [16MHz 5V] Running on 16MHz and 5V, this board will remind you a lot of other Arduino compatible boards that you like. [12V DC] There is a voltage regulator on board, so it can accept up to 12V DC. [Connect for "RAW"] If you are supplying an unstable power supply board, be sure to connect to the for "RAW" not on the VCC pin. [Safe Protection] We have also added a PTC fuse and diode protection to the power circuit and to correct the RX and LED TX circuits. [Use it in] Suitable for DIY enthusiasts to developing, learning and testing Code and using school textbooks.