Adafruit HalloWing M4 Express

Adafruit HalloWing M4 Express features a skull-shaped ATSAM521 board with 3.3V logic/power and a 1.54" sized full-color IPS TFT. The ATSAMD51G18 board features 512KB of FLASH and 192KB of RAM operating at 120MHz and supports Arduino and CircuitPython. The HalloWing M4 express features 8MB of SPI Flash for storing images, animation, and sounds and a mono class-D speaker driver for 4Ω to 8Ω speakers. This board also features a reverse-mount light sensor, side-light NeoPixel LEDs for cool underlighting effects, a 3-axis accelerometer, and a 3.3V regulator with 500mA peak current output. The HalloWing M4 express offers JST-PH plugs on both sides of the board for connecting external devices. The 3-pin JST connectors connect to analog pins on the SAMD21 and the 4-pin JST connectors connect to the I2C port.


  • ATSAMD51G18 at 120MHz
    • 3.3V logic/power
    • 512KB of FLASH + 192KB of RAM
    • Can run Arduino or CircuitPython
  • 1.54" sized 240 x 240 full-color IPS TFT
  • 8MB of SPI Flash for storing images, sounds, and animations
  • 3-axis accelerometer
  • Reverse-mount light sensor
  • Mono Class-D speaker driver for 4Ω to 8Ω speakers
    • Up to 1W
    • Connected to a 12-bit DAC on the SAMD51
  • 4x side-light NeoPixel LEDs for cool underlighting effects
  • LiPoly battery port with built-in recharging capability
  • USB port for battery charging, programming, and debugging
  • 2x female header strips with Feather-compatible pinout
  • JST ports for Neopixels, sensor input, and I2C
  • 3.3V regulator with 500mA peak current output
  • Reset button
  • On-off switch


Adafruit HalloWing M4 Express


Published: 2019-10-15 | Updated: 2023-06-05