Seems like every great monster film sets off a chain of sequels. Bride of…, Son of…, Revenge of…, Teen Wolf Too (hey, they can’t all be winners).

Our electronic eyeball projects have spawned their own little franchise, with Pi Eyes, HalloWing, Monster M4SK and more. The arrival of the Matrix Portal M4 board made another sequel inevitable — this time a retro-style return to form of our first project of the series, but punching it up with bright colors, full-screen themes, and coded all in CircuitPython now.

This makes a nifty Halloween window or tabletop display. And it’s a not-too-daunting introduction to CircuitPython and graphics. When the Halloween season’s over…if you don’t keep the decorations up year ’round like some of us…everything can be repurposed into your own projects, or try out some others like a Moon phase clock.

This project requires:

• Adafruit Matrix Portal M4 board
• Any of our 64x32 pixel “HUB75” (not NeoPixel) RGB LED matrices
• USB C cable
• USB power supply with output of 2 Amps or more

This guide will get the software running on the bare Matrix Portal hardware. Mounting or supporting the clock in an enclosure or frame is left as an exercise to the reader.

Parts

You can use a USB C power supply or a USB micro B with a micro B to C adapter

If you'd like your LEDs diffused (and if your LED matrix is 4mm pitch or smaller), some acrylic may help:

Adafruit carries a number of 64x32 RGB LED Matrices, varying between the space between LEDs (pitch) and whether rigid or flexible. Choose your favorite - larger pitch means the display is larger, width and height-wise but with the same number of pixels, and larger may be easier to read further away. Smaller for near your desk, for example.