Arduino Micro

Overview

The Arduino Micro is the smallest Arduino board with built-in USB support, based on the ATmega32u4 microcontroller running at 16 MHz. Measuring just 48 × 18mm, it packs the core functionality of the Arduino Leonardo into a breadboard-compatible form factor, including native USB device emulation without a secondary USB-to-serial chip.

The board provides 20 digital I/O pins (7 PWM-capable), 12 analog input channels, and hardware Serial, I2C, and SPI interfaces. A 6-pin ISP header is included for direct AVR programming. The micro USB port serves for both power delivery and programming. Onboard 3.3V regulation supports mixed-voltage peripherals, and a 3.3V pin provides up to 50mA.

Like the Leonardo, the Micro can simultaneously appear to a host computer as a virtual serial port, USB mouse, and USB keyboard. This native USB HID capability is particularly valuable in compact installations where the board needs to interface with a computer without a dedicated microcontroller or host software.

The Micro is not shield-compatible due to its compact form factor, but its breadboard-friendly pin layout and small footprint make it ideal for embedding in finished projects, wearables, and custom enclosures where space is a premium concern.