Pro-Micro ATMEGA32U4-AU 5V 16MHz Development Board

The powerful MICRO is the Arduino compatible board. It is based on Arduino Microdesign. SPI, COM, and IIC bus interrupts make bus connections easier. It has 20 digital input/output pins (7 of them can be used as PWM outputs and 12 are used as analog inputs), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP plug and a reset Button.