SparkFun Arduino Pro Micro 3.3V/8Mhz

The SparkFun Pro Micro Board is similar to the SparkFun Pro Mini, except that it features an ATmega32U4 onboard. The integrated USB transceiver allows the Pro Micro to be used as a keyboard, for example (like the Arduino Leonardo).

This small board also includes all the other features we expect from Arduino: 4 ADC channels, 5 PWM pins, 12 digital I/Os, and a hardware serial connection.

The board is powered by 3.3 V and is clocked at 8 MHz.

This board uses the special "Diskloader" as its bootloader.

Features:

• ATMega 32U4, clocked at 8 MHz
• Operating voltage 3.3 V
• Full support with Arduino IDE v1.0 (uncomment the "Leonardo" lines in the "boards.txt" file)
• Micro-USB connector for programming and power supply
• 4 x 10-bit ADC pins
• 12 x digital I/Os (5 of which are PWM)
• Rx and Tx hardware serial connections
• The smallest Arduino-compatible board from SparkFun!.