Blog: entries tagged with "midi"

The Bee and the Express

Express: back panel test mount I’m finally back to working on some electronic projects. First up, the Express, an analog-to-MIDI converter built around a Bare Bones Board, an inexpensive Arduino clone.

I’ve been making up some patches for my Evolver synth to use it as an effect on guitar or bass, and thought it’d be nice to have some sort of pedal to control it, along the lines of a wah or volume pedal. The desktop model of the Evolver lacks a pedal input, hence the Express (for “expression”, both of the musical and genetic kind - evolution, geddit?). Currently, it reads one analog pin and spits out continuous controller data. Nothing particularly spectacular there, but it did fit wonderfully into the sturdy steel case from a computer keyboard A/B switchbox. There’s room for lots more inputs, and eventually I figure it’ll sport an additional analog in and some footswitch inputs which will send things like note on/off messages.

I’m still new to making enclosures, and to working metal in particular - instead of grinding out a hole that was slightly too narrow, I used a drill, which grabbed hold of the edges and warped the heck out of the front panel. Panic set in for a moment, but I managed to bash the thing back into shape using a busted old hard drive(!) as an anvil.

Word to the wise: there are two incompatible standards for the wiring of expression pedals:

1/4” - tip to wiper / ring to +5V / sleeve to ground: Clavia, CME, Electrix, Emu, Kurzweil, Oberheim, Roland/Boss
1/4” - ring to wiper / tip to +5V / sleeve to ground: Kawai, Korg, Yamaha

The former arrangement allows you to use a standard normalling jack to connect the tip to ground by default, so the input doesn’t float if nothing’s plugged in. I’m using a Boss pedal now, but my other pedal is a Yamaha, so if I want to use it as a second input, I’ll have to wire up something to cross those connections.

Arduino (and Tarquin) Being easily distractible by possibilities - giant trackball! LED matrix! stepper motor-controlled time-lapse photography! - I’m desperately trying to focus on a couple of projects at a time. Arduino project number two at present is using it for ultra-cheap and dirty sound generation, with piezo disc speakers plugged directly into the digital outputs. A little hacked-together code, and voilà:

The Bee (MP3, 640k)

I call it the Bee, though “Mosquito” might have been more appropriate. Modulating the pulse width creates some nice motion, but there’s a lot more to do, like getting R/C filters to tame some of the harshness - it really is annoying after a while. Oh yes, and putting a switch on it to shut it up between tests. And, of course, buttons and knobs to play it with… maybe even some sort of acoustic treatment, like a resonating soundbox or a spring reverb.

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Just like homemade

Neat project: Freqtric, a system that senses body contact and uses it to trigger MIDI drums (and presumably other instruments).

I don’t know if this is part of the device, or future plans for it, but I’d love to see a version that senses which two people have made contact - imagine a dance piece choreographed around a system like that! Ideally it’d be wireless, but that would kind of defeat the skin-resistance effect the Freqtric project uses. Maybe something using conductive gloves…

IMAGETaste of the Danforth was this weekend. Utter madness. One mile of Danforth closed while hundreds of thousands of people mill about lining up for cheap food and free samples. We caught a few minutes of music from a Cuban band, which caught my ear because I’ve been working on a new arrangement for “Catch-22”, our ostensibly Latin number. Sat up into the wee hours last night hammering out a bassline for it. It’s gonna groove.

Also, this week has been awesome for jamming. Found a very cool bunch of folks who are into free-form living room music-making. Very excited!

Also, my latest score from Active: DPDT switches, for the making of stomp boxes.

Also, I salvaged the caster “tree” from a dead swivel chair and a busted coat rack from the office, for the making of percussion stands.

I’ve rediscovered my true packrat nature. I’d been denying it for some years - partly I was paring things down, partly I was influenced by my SO’s firm belief in chucking things that don’t get used, partly it was because we move house every year or two. But now my packratting has purpose. I actually am building things with the junk I collect. Castoff things are an opportunity.

Building things from materials at hand - it’s a trait I inherited from my parents, and I think the whole attitude is one of their greatest gifts to me. Almost every piece of furniture we had was either a hand-me-down, bought used, or home-made. We just didn’t buy new things unless we really needed them.

  • For much of my childhood, our couch in the living room consisted of sleeping bags laid on top of foam on a bed of old wooden microscope boxes (which were all filled with old books, or tools, or five-pound chunks of rock with embedded fossils).
  • We had a little tractor/riding mower - that was bought new. But my dad built the trailer for it by sticking a box made of pegboard on top of an old lawn mower frame.
  • Mum sewed stuffed toys, including a whole basket of vegetables and a completely awesome dragon. Most of my toys were homemade too.

Of course, this filtered through to me - I’ve mentioned the surplus walkman before. On the music-making front, I made use of: kitchen utensils; cassette tape loops; weird instruments my parents had collected, like a psaltery, a manjolin, an ocarina; an early PC speech synthesizer fed through a disembowelled toy spring reverb; sound effects records spun slow, fast, and backwards; an electric guitar with its signal crammed through a Commodore monitor and my mum’s walkman speakers (I toasted them, along with many other devices); and a practice chanter for learning the bagpipes. These all showed up in the recordings of the Spastic Attack Dogs (a grand high school band name if ever there was one) - who reunited after university, learned to actually play, and became Flickershow.

After I moved out, I snagged an old wooden door from Mum and Dad’s place, propped it up on a pair of cabinets, and used it as a desk. It worked well except for the layers of peeling paint on it, which got worse due to me spilling water on it and frequently using it for drum practice. When my BF and I moved into our first apartment together in Toronto, I decided it was time to strip the paint off it. It turned out there was a layer of milk paint on it that wouldn’t budge, so we gave up, sanded the bugger to a splotchy, hideous, but smooth finish, and got new legs for it at Ikea. I still get ribbed about the “Eli and his *&#$ door” incident, but it’s big enough for two monitors, a synthesizer keyboard, a printer and a mixer, and I never see the surface of it anyway.

So of course I was delighted to discover ReadyMade, which is a magazine aimed square at people like me. Looks very cool - I even tried to subscribe, but their online subscription system broke in several ways and I got fed up. Will have to let them know.

So here’s my ongoing list of electronics projects, in rough order of difficulty:

  • An expression pedal (based around a fader rather than a rotary pot) - the electronics are bonehead simple; it’s the woodworking to make the rocker that’s the tricky bit. Starting with locating our hand saw.
  • A box with a simple photocell circuit for use an an expression-pedal input. Controlling something like the FilterQueen will require a more complex thing with a transistor or two, but I ain’t ready for that yet.
  • A ribbon controller. (All praise the late John Simonton.)
  • A simple fuzzbox circuit or two, snagged off the web (there’s loads of DIY stompbox circuits out there).
  • And way down the road: a “fretless” electronic instrument that feeds a signal from a piezo pickup through an analog-delay comb filter with the feedback turned way up, creating a ringing tone. The delay rate, and thus the pitch, is determined by a ribbon controller. I’m picturing two or three of these stacked together to resemble a very nerdy guitar. Left hand fingers notes on the ribbon-controller strings; right hand thumps and taps and scrapes a set of pads in which the piezo pickups are embedded. There’s another control for damping/feedback, but I don’t know how that’s handled yet. Lots of learning to go before I tackle that… but it’s one I’ve had in mind for a long while.

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