Feather is the new development board from Adafruit, and like its namesake it is thin, light, and lets you fly! We designed Feather to be a new standard for portable microcontroller cores.

This is the Adafruit Feather 32u4 Adalogger - our take on an 'all-in-one' datalogger (or data-reader) with built in USB and battery charging. Its an Adafruit Feather 32u4 with a microSD holder ready to rock! We have other boards in the Feather family, check'em out here

At the Feather 32u4's heart is at ATmega32u4 clocked at 8 MHz and at 3.3V logic, a chip setup we've had tons of experience with as it's the same as the Flora. 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, then plug in the USB to recharge. The Feather 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.

Here's some handy specs! Like all Feather 32u4's you get:

Measures 2.0" x 0.9" x 0.28" (51mm x 23mm x 8mm) without headers soldered in
Light as a (large?) feather - 5.1 grams
ATmega32u4 @ 8MHz with 3.3V logic/power
3.3V regulator with 500mA peak current output
USB native support, comes with USB bootloader and serial port debugging
You also get tons of pins - 20 GPIO pins
Hardware Serial, hardware I2C, hardware SPI support
7 x PWM pins
10 x analog inputs
Built in 100mA lipoly charger with charging status indicator LED
Pin #13 red LED for general purpose blinking
Power/enable pin
4 mounting holes
Reset button

The Feather 32u4 Adalogger uses the extra space left over to add MicroSD + a green LED:

Pin #8 green LED for your blinking pleasure
MicroSD card holder for adding as much storage as you could possibly want, for reading or writing.

Comes fully assembled and tested, with a USB bootloader that lets you quickly use it with the Arduino IDE. We also toss in some header so you can solder it in and plug into a solderless breadboard. Lipoly battery, MicroSD card and USB cable not included (but we do have lots of options in the shop if you'd like!)

Check out our tutorial for all sorts of details, including schematics, files, IDE instructions, and more!

Technical Details: