[RESOLVED]Skywriter theremin.pd demo does not work



I had a bit of fun getting my skywriter hat to work but a firmware update fixed that.

Now I have tried all the demos and they all work great except the theremin.pd in the skywriter-hat/python/examples/ folder.

The README.md states that you need to install pd. Done that and the “synth.py” demo works fine so I am guessing it is installed OK.

When I try and run it with the prescribed
pd theremin.pd

I just get

sh: 1: wish: not found watchdog: signaling pd... watchdog: signaling pd...
which just repeats for ever

what am I doing wrong?

has anyone got this demo working, it sounds really exciting so I was surprised to find no videos of it running on YouTube.

Show off your musical prowess and melodic genius with this groundbreaking 3D theremin.

I am running it in X on HDMI Raspberry Pi 2 Raspbian


The synth.py demo is, in fact, the Theremin, it’s just very poorly named!

The theramin.pd file is actually baked into the little pdtone.py python library which synth.py loads, so they’re effectively the same thing. ( open pdtone.py and scroll riiiiight down to see this for yourself )

theremin.pd is, however, provided so you can have a go at tinkering with it and making your own puredata setup. To use it, you should install puredata-gui and then you’ll find “Pure Data” in Menu -> Sound & Video.

Open up Pure Data and you’ll be able to use it to open the theremin.pd file and figure out what makes it tick.

At the moment, though, pdtone.py doesn’t readily support connecting to a pd instance you’ve started yourself, but it should be a relatively easy tweak- you can probably just comment out the line self.start_pd().

Once you’ve created and saved your own twist on theremin.pd you can change the call to PDTone() in synth.py to load it, by supplying the filename:

tone = PDTone("myownpdfile.pd")

PD is a little bit mind-bending, but quite fun. I can’t attest to have got my head around it yet!


Boy do I feel stupid. I expected a 3D gui app representing the theremin on screen, maybe a job me for me (another day).

thanks for the quick reply.


This is something I’d love to see- my experience with 3D is very, very limited ( some WebGL stuff ) - although in retrospect it strikes me it could be faked pretty well in 2D isometric… in fact you could make an isometric game with the Skywriter as the input :D


Thanks for those explanations!

Was able to tweak David Gurney’s Voice Granulator patch to accept the Skywriter X/Y/Z input on the Pi. (Had already tweaked the same patch for accelerometer input from Touch OSC.)
Really nice effect. Running into some audio problems after a while, maybe because it’s too taxing on the Pi. Might use the same thing to drive a Pd patch on a more powerful machine.