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Thread: [posted] MIDI Joystick

  1. #1
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    [posted] MIDI Joystick

    This might not be a very exciting project, but it's solved a couple problems for me. I wanted to control a synthesizer from my organ, but I wanted a physical control for pitch bend and modulation, which the organ doesn't have. Also, I can't plug the organ into the synthesizer because the MIDI control change (CC) messages are sent to the synth when I don't want them to be. I can't disable the sending or receiving of MIDI on either instrument. Normally when I play a gig, I would need to bring a second keyboard to control the synth, which is a pain. So I built this little joystick box to give me a physical control and also filter the MIDI messages. My first gig with this setup is tonight and I'm pretty excited!

    I used a Teensy 3.2









    I'm also considering building another version of this that operates on audio signals, so you could add pitch bend to any keyboard, even vintage, electro-mechanical pianos. I would need a Teensy 3.5 for the FPU and the audio shield. And I would need to implement the phase vocoder technique in order to change the pitch of the signal, but I think I'm at a point where I could tackle this challenge. Besides the hardest part of any project seems to be drilling the holes in the right place!

  2. #2
    Senior Member oddson's Avatar
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    Die cast enclose, clean, solid looking perf-board. Gig-worthy build.

    ...the hardest part of any project seems to be drilling the holes in the right place!
    So true... looks like you did a great job on this one though.

    I don't think a phase vocoder is available in the audio library and I don't think it's likely anytime soon.

    (That's not a particularly informed opinion so perhaps someone more familiar with the algorithm can say if it's feasible with the current library framework on a T3.6 to produce a reasonably realistic pitch-shift within a reasonable latency. )

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    Nice job on the packaging and good luck with the gig
    Wouldn't it be easier to play if the pitch bend and modulation were foot controls (i.e. expression/swell pedals) rather than a joystick?

    Pete

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    Quote Originally Posted by oddson View Post
    Die cast enclose, clean, solid looking perf-board. Gig-worthy build.
    Thanks!

    Quote Originally Posted by oddson View Post
    So true... looks like you did a great job on this one though.
    The hardest park was the 2 big hole sfor the Midi Jacks, I was a few millimeters off on the initial hole, so the don't line up very well. You can't really see that in the picture though. I still don't have a good strategy for figuring out where the holes should be drilled. The square-ish usb hole was tricky too. Had to dremel it out with the conical grinding bit.

    Quote Originally Posted by oddson View Post
    I don't think a phase vocoder is available in the audio library and I don't think it's likely anytime soon.
    Yea, I know, but I have the lofty goal of adding it to the library myself. I have an audio shield and a Teensy 3.5 that I put into another project, but I'm not using that project so I might re-purpose it for the pitch shifting idea, since it'll be a more interesting project.

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    Quote Originally Posted by el_supremo View Post
    Nice job on the packaging and good luck with the gig
    Wouldn't it be easier to play if the pitch bend and modulation were foot controls (i.e. expression/swell pedals) rather than a joystick?

    Pete
    Totally! I've thought about adding a jack to attach a foot pedal for this. I would need to practice using my foot for that. I've tried this before with a synth that could be programmed to do this, but it was much harder than I though.

  6. #6
    Senior Member oddson's Avatar
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    Foot pedals are fine for volume or pan or altering the cutoff of a filter but pitchbending notes would have to be limited to one direction with full up or down as the 'no bend' setting otherwise it's too hard to find and stick to the center pitch when you want to stay in tune.

    Unless there's a middle-position-spring-return pedal out there somewhere already or your fabrication chops are much better than someone who admits they have trouble lining up wholes

    If I really wanted foot-controlled pitch bend I'd try a pair of load sensors to provide a ratio value that returns to unity when released and bend could be read from relative heal/toe pressures.

    Edit - hmm that's what that dead bathroom scale could be used for.

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    You're right. Pitch bend doesn't easily work with a foot pedal. The modulation might work out though.

    Pete

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    Quote Originally Posted by el_supremo View Post
    You're right. Pitch bend doesn't easily work with a foot pedal. The modulation might work out though.

    Pete
    Some sustain pedals that support "half-pedaling", like the Roland DP-10, are actually continuous. Once I set one up to do upward pitch bends on an Ultranova synth and it worked surprisingly well! There was definitely a learning curve though, so it would take some practice to make it sound good. If you had 3 of these, you could have pitch up, pitch down, and modulation. I think that would be the best way to control this stuff with your feet.

  9. #9
    Administrator Robin's Avatar
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    Great project! I posted this to the project blog on hour home page.
    https://www.pjrc.com/midi-joystick/

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