We’re going to connect the Gemma M0 to the battery, Neopixel ring, and LED, using heat shrink tubing to secure connections. After that, we should be able to use the capacitive touch module on the Gemma M0 to directly trigger the LED.

Here’s a wiring table, courtesy of Adafruit, just in case you’re stuck:

Software

Here’s what you’ll need on the software side to get cracking:

• Arduino IDE (1.8 or newer preferred)
• Adafruit Board support for Gemma M0
• Arduino libraries: FastLED, Adafruit_FreeTouch, Adafruit_NeoPixel
  • These can be installed from the Arduino Library Manager. Go to Sketch > Include Library >Manage Libraries… and search for all or part of the library’s name, then click “Install.” You’ll need to look for:
    • FastLED
    • Adafruit_FreeTouch
    • Adafruit_NeoPixel

After you’re all set up in the software department, flash some code onto the Gemma M0, and then we can get right along to printing the horn!

Printing Time

You could print the horn in two materials or colors if you’re being fancy, but there’s also a merged single-extruder version:

• Horn
• Spiral
• Mounting Platform (print no matter what)
• Merged horn and spiral (single extruder only)

The designer recommends printing the horn with 0% infill, and no supports or raft; but printing the platform with 20%, as well as supports and a raft. Though in both cases, a skirt or brim can be helpful, depending on your setup. If you’re not sure if you need them, this basic guide might be a good starting point.

First, assemble the little electronic contraption shown in the diagram. That’s the most difficult part. After that, all you need to do is attach the copper tape to the outside of the horn, then connect the tape to the Gemma M0 board, and you’ve got a light-up horn!

You’ll probably want to attach the horn to a headband of stiff fabric to wear it on your head – to do this, sew the platform onto the fabric using the mounting holes. Don’t forget to use a stretch strip of cloth elastic on the ends for a comfortable fit.

At this point, you might face some issues with sensitivity: the capacitive sensor’s readings may fluctuate wildly and require slight tuning before the horn can light up on command. Adafruit has provided detailed steps on this calibration process, if it becomes a problem.

Otherwise, you’re all set to be the life of the mythical animals party!