Homemade Teensyduino pedal works well with Loopy

edited October 2012 in Equipment

I built a six-button stomp pedal with the $16 Teensy USB Development Board


Via Teensyduino the board can act as either a USB keyboard or as a USB MIDI device. I wired six momentary push buttons similar to these


to the binary inputs and adapted the USB keyboard and USB MIDI example sketches (source could be made available if there is interest).

For the pedal I installed aluminum tread plate over plywood and used scrap wood for the ends, poorly-lit cell phone photos attached.

When connecting to iPad/iPhone as a USB keyboard, a dialog saying the USB device is not supported is shown, but it works fine regardless. Go to the Key Mapping configuration in Loopy and map button presses to Loopy actions.

Connecting to iPad/iPhone as a USB MIDI device also works well, go to the MIDI Key Mapping configuration in Loopy.


  • heuermh

    "adapted the USB keyboard and USB MIDI example sketches (source could be made available if there is interest)."

    Very interested!

    Please add some links or comments on how to...


  • I would be interested in your Arduino sketch or will it only work with Teensyduino?

  • That's a thing of beauty.

  • Thank you all for your interest!

    I honestly could not provide a better write-up than the following by Sebastian Tomczak a.k.a little-scale


    Follow those directions except wire push buttons to the digital inputs and ground (left side of Teensy chip) instead of wiring a pot to the analog inputs (right side of Teensy chip).

    Then for USB keyboard, select Tools --> USB Type --> Keyboard + Mouse + Joystick in Arduino and adapt the following sketch


    For USB MIDI, select Tools --> USB Type --> MIDI and adapt the following sketch


  • @MauiMacMan This might also work with Arduino proper, you'll just need to copy or adapt the Teensyduino Bounce class.

  • Thanks a lot for the detailed info. I've been looking into those teensy boards for many reasons, controllers being a main one with all the inputs.

    You're saying it works as usb HID keyboard (but with warning) and smoothly as usb MIDI controller?

    Camera connection kit for iPhone (iOS 6) depends on Cydia app?

  • @mikekuehn Yep on my iPad2 iOS 5.x it works smoothly as USB MIDI with the camera connection kit. I haven't updated to iOS 6 yet so I can't comment on that.

  • edited February 2015

    Nice idea on the pedal. I am still pondering how to use my cheap Bluetooth keyboard as a pedal by adding some bigger pads to 8 or 10 of the keys and putting it in a more rugged housing... With a $15 Bluetooth keyboard from amazon it can't cost much more than this arduino idea, right? ;-)

  • edited February 2015

    very good!

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