**** Cassettepunk ****

Happy New Year!

I’ve just finished surviving a New Years’ show masterminded by Bobbi-Jo Moore of The Elixxxirs. Let me briefly sing her praises first: she assembled and coordinated an army of volunteers to put together a “Back To The Future” themed party and Parkinsons fundraiser for 400, including the bar, decoration, promotion, lighting, sound, DJ, and endless loads of supplies. Not to mention actually playing the show. That’s a tremendous amount of work and risk to take on. She dug deep into her circle of friends to find help and they really came through. I’m impressed. It was a great night.

Since The Elixxxirs were representing 2015 (the future!) I thought it would be fun to do something interesting with the drums: a light show triggered by playing. Many have had this idea before — see, for example, Adafruit’s entry on the subject — but so far the examples have fallen a little short of the mark.

Here’s mine:

Like the above example, I used an Arduino-based controller (a Trinket) and Neopixel LED strips. For the trigger, I used a piezoelectric sensor, which is what most drum triggers use anyway, besides being cheap and easy to work with. Each unit was built into a small plastic chassis.

Assembly was basically trivial; a bit of dead-bugging, soldering directly onto the Trinket. I’ve long wanted to jump to working with AVR chips directly, rather than using the Arduino platform, but the Trinket is so cheap and easy to use that it’s simply not worth the trouble yet.

My first prototype had a couple of potentiometers mounted to adjust characteristics of the light show, but these proved unnecessary — it works well without any adjustment. (Not being able to use the USB connection to program the chip when you’ve got potentiometers connected to those AVR pins was a bit annoying. In the future I’d use a small connector to permit quick detachment of those pins.)

This was also my first experience working with Neopixels. These are great, if not all that cheap. It almost feels like cheating; these parts are basically snap-together.

I soldered directly onto the piezo pickup, which is the most fragile part of the whole affair. I hot-glued the wires down to help decrease the stress on the solder joints. Particularly when stuck down to the bass drum skin, there’s a lot of motion going on when I’m playing the drums. (See it in slow-motion.) Working with the bare piezo keeps the mass down, but even so, there’s a noticeable damping of the cymbals in particular. I taped the piezo into the underside of each cymbal fairly close to the bell to limit this.

The set-up worked flawlessly during the New Years’ show, with a little overzealous taping to keep the power cords in, the triggers attached, etc.; that won’t be a new requirement for a drummer, who will be used to surprise mid-song cymbal stand failure.

Source code on Github.

This would be a great project even for a drummer who has very limited experience with electronics or programming. The circuit and the code are both just about as easy as they can be.

More video to come, I hope!

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