The Pro Micro is similar to the Pro Mini except with an 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 8MHz and 3.3V, this board will remind you a lot of your other favorite Arduino-compatible boards but this little guy can go just about anywhere.
This is the 3.3V version so, as always, keep in mind the limits of system voltage and so forth. The lower system voltage also has its advantages, though, like ease of use with many common 3.3V sensors.
Note: As of June 19, 2012 these boards will be shipping with a slightly modified version of the same bootloader included with the Arduino Leonardo. It's modified to use our own VID and PID, so you Windows users will need to use the driver linked in the Add-on below. The "Pro Micro Add-on" download below will add SparkFun Pro Micro 3.3V/5V board selections to your Arduino IDE's "Tools > Board" menu, follow the instructions in the readme file to install it. You must select "SparkFun Pro Micro 3.3V/8MHz" when programming this board.
- ATMega 32U4 running at 3.3V/8MHz
- Supported under Arduino 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