Adafruit HalloWing M0 Express

Overview

The Adafruit HalloWing M0 Express is a skull-shaped development board combining the ATSAMD21G18 microcontroller with a built-in 1.44" 128×128 TFT color LCD, making it an all-in-one platform for animated eyes, badges, and interactive cosplay projects. The skull PCB shape is both a functional board and a visual design element.

The ATSAMD21G18 runs at 48 MHz with 256 KB flash and 32 KB SRAM, supplemented by 8 MB of SPI flash for storing images, animations, audio samples, and CircuitPython code. The 1.44" TFT displays full-color graphics at 128×128 resolution, and the Feather-compatible header strips expose GPIO for connecting additional components. Four capacitive touch pads on the outer edge of the skull provide touch-sensitive input without physical buttons.

Onboard sensors include a 3-axis accelerometer for motion/tilt detection and a light sensor for ambient brightness measurement — both useful for creating reactive animated displays. A Class-D mono speaker driver capable of 2W into 4-8Ω speakers enables audio playback and sound effects. JST-PH connectors provide access to NeoPixel chains, additional sensors, and I2C peripherals. A LiPo connector with built-in charging enables battery-powered operation.

The HalloWing ships with CircuitPython pre-installed and is compatible with the Arduino IDE. It is most commonly used for animatronic eye projects (including servo-controlled realistic eyes), wearable cosplay props, interactive Halloween decorations, and novelty badges — any project benefiting from a built-in TFT screen in an unusual form factor.