What is Adafruit Feather?
Adafruit Feather is a family of thin, lightweight development boards made for prototyping. They are designed to be used on their own, or are stackable for multiple functionalities. Feather boards can be both battery operated or have a microUSB port for a PSU to be connected.
There is a family of products surrounding the Adafruit Feather range to help you get your projects up and running.

More about the Feather 32u4 Bluefruit LE …
The Adafruit Feather 32u4 Bluefruit LE is a Bluetooth Low Energy (BTLE) board. BTLE is a low-power, 2.4GHz wireless protocol. It is a popular protocol amongst smart phones.
The ATmega32u4 BTLE chip has 32K of FLASH memory and 2K of RAM. It also offers USB-to-Serial programming and debugging without the need for an FTDI-like chip.
The Feather 32u4 Bluefruit LE also features the Bluefruit BTLE module, plus two status indicator LEDs. The Bluefruit LE module is the nRF51822 chipset from Nordic which has be programmed to provide multiple different functions. The Bluefruit can be used as a standard UART RX/TX connection profile or it cant act as a data connection between devices. The Bluefruit App for iOS or Android is designed to help you prototype your projects, controlled by your phone or tablet.

It’s portable!
You have the option to use either a 3.7V Lithium polymer battery, or connect to a PSU via microUSB. If you choose to power your board by battery, it makes it portable. So you can take it with you, wherever you need to. If you need to recharge it at any point, just plug it in via the microUSB and it will recharge.
The BTLE functionality of this board also makes it ideal for use in portable items, when you might use an iOS or Android smartphone or tablet.

Here’s the facts & figures:
Bluetooth: ATmega32u4 @ 8MHz with 3.3V logic/power
Power: 3.3V regulator with 500mA peak current output
PWM: 7 x pins
Inputs: Analogue x 10
Size: 51 x 23 x 8 mm (without headers)
Featherweight: 5.7g
Charging: Built in 100mA LiPoly charger with charging status indicator light

Lipoly battery and USB cable not included.

Adafruit Feather 32u4 Development Boards

The Feather 32u4 is a range of development boards from Adafruit. They are powered by the Atmel ATmega32u4 microcontroller clocked at 8 MHz with 3.3 V logic. This chip has 32K of flash and 2K of RAM and built-in USB. As a result it has a USB-to-Serial programme and debug capability built in and it can also act like a mouse, keyboard, USB MIDI device.

This chip is supported in the Arduino IDE and can run nearly every sensor/library available.

The Feather is perfect for small or portable projects. There is a connector for 3.7 V Lithium polymer batteries and built-in battery charging circuit which you can use to measure and monitor battery levels. Lithium Polymer battery and USB cable not included.

Supplied fully assembled and tested, with a USB bootloader that lets you quickly use it with the Arduino IDE.

- 51 x 23 x 8 mm / 2.0" x 0.9" x 0.28" (without headers)
- 4.8 grams
- 3 V regulator with 500 mA peak current output
- 20 GPIO pins
- Hardware serial, hardware I²C, hardware SPI support
- 8 x PWM pins
- 10 x analogue inputs (one is used to measure the battery voltage)
- Built in 100 mA lithium polymer charger with charging status indicator LED
- Pin #13 red LED
- Power/enable pin
- 4 mounting holes
- Reset button