The DEV12640 Pro Micro 5V/16MHz is similar to the Pro Mini except with an ATmega32U4 on board.
The USB transceiver inside the 32U4 allows us to add USB connectivity onboard and do away with bulky external USB interface.
This tiny little board does all of the neato Arduino tricks that you're familiar with: 4 channels of 10bit 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 Arduinocompatible boards but this little guy can go just about anywhere. There is a voltage regulator on board so it can accept voltage up to 12VDC. 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.
Dimensions: 1.3x0.7
Features:
ATmega32U4 running at 5V/16MHz
Supported under Arduino IDE v1.0.1
OnBoard microUSB connector for programming
4 x 10bit ADC pins
12 x Digital I/Os (5 are PWM capable)
Rx and Tx Hardware Serial Connections
Our Smallest ArduinoCompatible Board Yet!
Documents:
Schematic
Eagle Files
Hookup Guide
Datasheet (ATmega32U4)
Firmware Note
Arduino Addon Files