haxo-hw VS Audio

The designer here. You can monitor the project to build fully assembled haxophones on this page. And here you can see an instrument built by one of the project followers. Feel free to contact me directly for questions or feedback. Cheers!

See this discussion on github: https://github.com/jcard0na/haxo-hw/discussions/10 You will see that there is a person there (raychmond) who's ordered a batch of 5 PCBs and has an extra one. Maybe no one has claimed it yet and you can get it from him.

Actually the pressure sensor is on the PCB. Pressure is transferred from the mouthpiece through a flexible silicon pipe. You can see the details in the assembly instructions here: https://github.com/jcard0na/haxo-hw/blob/main/docs/assembly....

Teensy which gives you a lot of options with its audio library and GUI tool.

Teensy is more powerful than Arduino, 4.X boards are in stock, 8 sets of serial ports, and has a supported audio library

Just in case you don't want to go from low level code and up this is the library development version (there is a release version that you install into the Arduino environment as well) and this is the GUI that makes it simpler to do the layout work for the modules of your device to make it more straight forward to do the build of the design work. You drag the modules from the left into the work area and then connect them up. Once you have the layout you want you then export the code for it into the Arduino IDE. In the right hand panel is the description of each module and what commands are used for it in the IDE.

If you are targetting microprocessors, you are probably best coding it from scratch so you can optimise. Teensy 4 seems to be the platform of choice for a lot of synth projects. The Teensy Audio Library might give you a bit of a head start. Dexed-micro touch is a great open project that can give you an idea of what is possible on Teensy and the dev is quite approachable.

You can overcome the RPi scarcity by migrating the code to the Teensy platform, which aside being cheaper and less power hungry than the 2,3,4 RPi, is a lot cheaper and more easily available. Not an easy task since there's no Linux under the hood, but there are some excellent audio/midi libraries to help. They already built commercial-level synthesizers with it. By combining the breath sensor data with other pressure sensors you could end up with a very expressive instrument.

https://www.pjrc.com/teensy/index.html

https://www.pjrc.com/teensy/td_libs_Audio.html

https://www.pjrc.com/teensy/td_libs_MIDI.html

https://www.youtube.com/watch?v=z2674LdYW5I

Personally, if I need to make custom software modules and design my own PCBs, I'm almost certainly not going to use something like LightShowPi as my starting code. I'd probably use a Teensy + Audio Shield + EL Sequencer and have the Teensy Audio Library do all the FFT/beat detection. It'd be much more power efficient, easier (IMHO) to build and maintain, and it still allows for expansion options for future add-ons. Funny thing is, I actually own an El Escudo Dos, but I have found it to be a giant PITA compared to simple edge-lit "Neon" LED strips or even the newer "nOOds" from Adafruit.

> Silly question but why is the Pi necessary?

Not sure about this project, but generally it is not. All it needs is a small board capable of running Linux and the necessary drivers for external ADCs/DACs where necessary, plus the digital fx software. As an example, Guitarix runs also on ARM and can work on cheaper boards such as the Orange PI, Nano PI and many others cheaper and more obtanium than the Raspberry PI. https://guitarix.org/

In some cases you don't even need to run Linux. There are many effects projects using a cheap Teensy board plus its piggybacked audio card; it features a really powerful audio library and is compatible with the Arduino IDE.

https://www.pjrc.com/teensy/

https://www.pjrc.com/teensy/td_libs_Audio.html

The Teensy is truly amazing, to the point one can build synthesizers that just a few years ago would cost hundreds of bucks. Take a look for example at the TSynth, 100% Open Hardware & Open Source, also available in kit.

https://electrotechnique.cc/

Demo here: https://www.youtube.com/watch?v=uCA2L7CeWSE