PRO MICRO 5V/16MHZ Micro USB Leonardo
The Pro Micro is an Arduino compatible microcontroller development board based on the ATmega32U4 IC designed by Sparkfun Electronics. It is based around the Arduino Leonardo which means you no longer need an addition USB-Serial Interface to program your Arduino.
Leonardo The board is broken down into 24 individual pins and has 3 indication LEDs, one of which is dedicated to power. It features 4 channels of 10-bit ADC, 5 PWM pins, 12 DIOs as well as hardware serial connections Rx and Tx. This version run on 3.3V at 8 MHz and can also run on 12V supplied to the "RAW" pin.
ATMega 32U4 running at 5V/16MHz
Supported under IDE v1.0.1
On-Board micro-USB connector for programming
4 x 10-bit ADC pins
12 x Digital I/Os (5 are PWM capable)
Rx and Tx Hardware Serial Connections