When it comes to decoration for Halloween, or setting up an elaborate, Scooby Doo-esque plot to scare a bunch of meddling kids, it's hard to beat a creepy skull that looks at you out of one eye whenever it detects movement!

You can build this with the HalloWing and its TFT display, a lens, and a PIR sensor to determine when people are approaching, and then open up it's one good eye!


Here are the components you'll need:

1 x Adafruit HalloWing M0 Express
Skull-shaped ATSAMD21 board w 1.44" 128x128 TFT display
1 x Convex Glass Lens
with Edge - 40mm Diameter
1 x Clear Acrylic Lens Holder + Hardware Kit for HalloWing
The perfect kit for mounting a convex lens (glass or plastic) to your HalloWing! This holder has been laser-cut specifically for lenses with a lip-edge
1 x PIR (motion) sensor
Passive Infrared detector
1 x 5V 2.5A Switching power supply
with 20AWG MicroUSB Cable


The PIR sensor works best with 5V power, so battery usage will be better for a non-PIR reactive build. If you must use battery power and PIR you may want to add a PowerBoost converter for 5V power.

Parts & Tools

In addition to the parts listed above, you'll also need:

  • Hollow plastic decorative skull such as this one, you can find these at home stores and hardware stores, too.
  • Box cutter, hobby knife, or thin-bladed saw
  • Hot glue and hot melt glue gun, or double stick foam tape
  • Black felt or construction paper
  • Scissors

This guide was first published on Sep 07, 2018. It was last updated on Sep 07, 2018.

This page (Overview) was last updated on Nov 13, 2020.