Boneboard 32u4 Bonelogger - A combination of SD card read and write, USB and Lipo-battery charging all in one, ready to use controller for you! We have other boards in the Boneduino family, check'em out here!
At the Boneboard 32u4's heart is at ATmega32u4 clocked at 8 MHz and at 3.3V logic. This chip has 32K of flash and 2K of RAM, with built in USB so not only does it have a USB-to-Serial program & debug capability built in with no need for an FTDI-like chip, it can also act like a mouse, keyboard, USB MIDI device, etc.
To make it easy to use for portable projects, we added a connector for any of our 3.7V Lithium polymer batteries and built in battery charging. You don't need a battery, it will run just fine straight from the micro USB connector. But, if you do have a battery, you can take it on the go, and then plug in the USB to recharge. The Boneduino will automatically switch over to USB power when its available. We also tied the battery thru a divider to an analog pin, so you can measure and monitor the battery voltage to detect when you need a recharge.
Specifications for Boneduino 32u4 series:
The Boneduino 32u4 Bonelogger uses the extra space left over to add MicroSD + a green LED: