This is the Adafruit Feather 32u4 Adalogger - Adafruits take on an 'all-in-one' datalogger (or data-reader) with built in USB and battery charging.
At the Feather 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, Adafruit added a connector which works with 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. Adafruit 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.
- 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
- 8 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
- Dimensions: 51.1mm x 23mm x 8mm / 2.0" x 0.9" x 0.28" (without headers soldered in)
- Weight: 5.1g
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. Adafruit also tossed 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!)