The Open Woodwind Project

Been a while since an update, I'll admit that development has all but halted, and the reason is that I've fallen into analog Eurorack synthesizers. I still plan on coming back to development on this project, but not sure on timeline.

Check out this latest jam, showcasing my the Open Woodwind Controller:

The OWP_Synth now accepts an audio input, which can be selected to allow VCA, Filter, and Effects processing from external sound sources.

I've been able to do a lot more work with the synthesizer. Fun times!

Features list:

• Four Oscillators
  • Sine, Sawtooth, Variable Pulse and Variable Triangle
  • Gain, Detune, Pulse Width (for Pulse and Triangle) are able to be set
  • Portamento, during legato can be adjusted, and when the Portamento is modulated
• Pink and White Noise Generators
• 2 LFO Sine Wave Generators
  • 0Hz to 100Hz (adjustable in config to be more)
  • Gain, frequency and range can be modified by breath, expression, or modulation wheel
  • LFO destinations include Oscillator frequency, Oscillator Gain, and Filter Cutoff Frequency
  • LFO1 affect Waveforms 1 and 2, LFO2 affects Waveforms 3 and 4
• Low pass filter
  • Adjustable cutoff frequency offset, modulated by breath, expression, or modulation wheel
  • Adjustable resonance, modulated by breath, expression, or modulation wheel
• Waveform shaping
  • Four 'overdrive' banks that allow for waveform shaping with custom arbitrary waveforms
  • Gain for each waveform shaping is adjustable, overall bank can be modulated by breath, expression, and modulation wheel.
• Effects
  • Flange effect, adjustable
  • Stringy Chorus effect, adjustable (this is a modified chorus that stretches and re-integrates the audio blocks to sound more bowed instrument like)
  • Delay, with adjustable amount and time delay adjustments
  • Reverb, adjustable room size
• MIDI Note transposition via CC channel
• Fine tune via CC channel
• Save and Load patches to SD card (127 of them)
• Play backing tracks from the SD card (127 of them)
  • Adjustable volume via CC channel

Current source snap shots located on my Github Repository: https://github.com/jeffmhopkins/Open-Woodwind-Project/tree/master/src/owp_synth

Here are some screenshots of the OSC interface (via TouchOSC on an iPad) that I have running to control the synthesizer:

Since I'm using the Raspberry Pi as a base station for this project, I was able to get an OSC to MIDI bridge running which allows me to run the TouchOSC app on an iPad with a custom GUI.

The Raspberry Pi is running 'osc2midi' (an OSC to MIDI bridge) and 'a2jmidid' (a MIDI to ALSA bridge) which all gets auto patched via 'qjackctl' (The Jack patching session manager).

The end result, is that OSC messages coming from the TouchOSC GUI on the iPad is wirelessly transmitted via the Pi Hotspot (or local WiFi).

There needs to be a configuration file written for osc2midi to map the GUI to MIDI channels, but I loaded this up on GitHub for those who want to replicate.

https://github.com/jeffmhopkins/Open-Woodwind-Project/blob/master/touchosc/custom.omm

The new microcontroller came in, and this time the real 'onboard' synthesizer is being demonstrated. The Pi will probably still be on the base station, but this synth will run directly on the microcontroller, without the need for external anything.

I've also added the sourcecode to a four oscillator woodwind controller synth to github for the Teensy 4.0: https://github.com/jeffmhopkins/Open-Woodwind-Project/blob/master/owp4/owp_synth.ino

Here's a demo of some upper octave stuff to show the aliasing:

https://soundcloud.com/jeff-m-hopkins/open-woodwind-project-teensy-library-upper-octave-testing

Final Designs

So I have finished the final 3D CAD files, and printed out the body. I'm having the keys cut out of carbon fiber, and then I have a bunch of prep work (sanding, filling, painting, veneering) ahead of me to to turn the 3D printed body into a 'final' instrument.

I'll be dropping all new electronics in this instrument, but basically the same setup. Teensy 4.0 with audio shield this time, and wireless MIDI, but the basics will be the same. Two MPR121s, pressure transducer and accelerometer/IMU.

Stay tuned!

In this quarantine I've also been able to play a bit with using a Raspberry Pi as a sound source. Using the ALSA Modular Synthesizer I've got this patch going: