diymore Pro Micro ATmega32U4 16MHz 5V with 2-Row Pins Header Module Board for Arduino Leonardo

Note: This is a plug-and-play board with the Arduino Leonardo driver. Download the Arduino software first and then plug in the motherboard to automatically install the driver.
Features:

The Pro Micro is similar to the Pro mini except with a ATmega32U4 on board.

The USB transceiver inside the 32U4 allows us to add USB connectivity on board and do away with bulky external USB interface.

This tiny little board does all of the neat-o Arduino tricks that you're familiar with:

4 channels of 10-bit ADC, 5 PWM pins, 12 DIOs as well as hardware serial connections Rx and Tx.

Running at 16MHz and 5V, this board will remind you a lot of your other favorite Arduino-compatible boards but this little guy can go just about anywhere.

There is a voltage regulator on board so it can accept voltage up to DC 12V. If you're supplying unregulated power to the board, be sure to connect to the "RAW" pin on not VCC.

This latest revision corrects the silk error from the last version of the board so that pin 14 is correctly labeled.

We've also added a PTC fuse and diode protection to the power circuit and corrected the RX and TX LED circuit.

Specifications:

ATmega32U4 running at 5V/16MHz

Supported under Arduino IDE v 1.0. 1

4 x 10-bit ADC pins

12 x Digital I/Os (5 are PWM capable)

On-Board micro-USB connector for programming

Rx and Tx Hardware Serial Connections

Package Included: 1 x Pro Micro ATmega32U4 16MHz 5V2 x Row Pins Header