Adafruit Feather 32u4 Bluefruit LE engineering development tool

Arduino-compatible board with Bluetooth Low Energy

The Adafruit Feather 32u4 Bluefruit LE combines an ATmega32u4 running at 8 MHz and 3.3V logic with integrated Bluetooth Low Energy on the 2.4 GHz spectrum. It targets makers building portable projects that communicate with iOS, Android, macOS or Windows 8+ devices without special certification. USB native support provides a built-in bootloader and serial debugging without an extra FTDI-style chip. The board also functions as a USB mouse, keyboard or MIDI device.

Battery charging and hardware peripherals

A 3.7V lithium-polymer connector with on-board charging lets the board run untethered or directly from the micro-USB supply. Hardware serial, I2C and SPI are available for sensors, displays or other modules. These integrated peripherals remove the need for separate level-shifting or adapter boards in many portable designs. The Feather form factor keeps the layout compact for space-constrained enclosures.

Limits of the 8 MHz 3.3V platform

The 8 MHz clock and 3.3V logic restrict performance for compute-intensive tasks such as real-time audio processing or high-speed data logging. Bluetooth Low Energy throughput is bounded by the protocol and the 2.4 GHz radio, not by the USB interface. Projects needing more flash, RAM or CPU cycles will outgrow this board. Builds requiring 5V I/O or faster SPI clock rates need a different platform.