Compiling Pure Data patches to run on OWL

Here’s the original instructions I received by email to prepare Pure Data patches for running on the OWL

Quick instructions on making patches:

  1. create an account on if you haven’t already and Sign in
  2. download a PD patch to use as a starting point, e.g.
  3. go to Patches / My Patches / Create new patch
  4. fill in the details and either upload your PD file or link to it on GitHub
  5. submit, then click the Compile link
  6. if all went well, download sysex and load it up to the OWL using OwlControl

However, I’ve had no luck trying to do this.

* Have not been able to upload a pd file from my own computer. When I select a file from my HD, nothing appears to happen.

* Attempting to compile the pd template from GitHub, it fails compilation with a string of messages indicating problems in the pd file that are not evident on examination

* Same file submitted directly to the Enzien Heavey Audio Compiler also fails, but with different messages. Maybe this is because the middleware of OWL was eliminated?

* The purpose and use of most of the fields in the New Patch form are complete mysteries to me. Can I get some explanation?


To be honest I’m not very good with PD and haven’t actually used that template.
The send objects are there to simulate the knobs when you run it in PD, they should be removed when compiling for the OWL.
Everything between the adc~ and dac~ is to do with translating between samples and frequency parameters, in case you want 1v/oct pitch on the audio connections. Unless you’re doing something like an oscillator or sequencer and want sample accurate data this can simply be removed.

Did you try with a different PD patch, e.g. one of these

About file uploading:
After you’ve chosen the file on your filesystem you then submit the Patch Details form.
This should bring up the patch page, with your file displayed. Is this not working?
From here you can then click Compile to run the online compiler.

We’re working on a smoother process so that an uploaded file can be updated directly from the patch page. At the moment you have to go back to Edit patch.

That's correct. When I select a file, nothing visible happens. When the patch is saved, there's no prompt to compile or download.

The only way I can compile my patches is to upload them to my own repository. This works.

These patches work okay. It’s just the template file that seems to be corrupt in some way. When I delete parts of it, it still fails to compile. When I delete everything and build a new patch in the same file, it compiles.

The process as it is not so bad, except for the bits that don’t work. Fixing the upload and replacing the template file will be very helpful. Let me know if I can help by testing.

The file upload bug has now been fixed.
After selecting a file, the field will be filled with a url pointing to the server.

After you submit, you will see the file displayed, and be presented with a Compile button.

Thanks, Martin! I’ll try it out later today.

Excuse my hijacking this post, but it couldn’t be a more perfect title. What is the status of the Heavy compilation process for the Owl at the moment? I’ve uploaded one of the example pd patches on the Owl site to the Heavy site, and it compiles okay. I see C files, among other things. But what do I do with them? It looks (on the video on the owl News feed) like I should be using some downloaded version of Heavy to compile on my mac. On Github I only see a read file in that project. And on the Owl site the documentation main link seems to be down, so I can’t find anything else out, except for here on the forum. It’s all very strange…

I’m very keen on getting this sorted. Please let me know how to proceed. (I don’t have to use heavy either, so would also welcome guidance regarding the earlier process - as the docs don’t seem to be working, I mean).


Sorry the docs are down, should be back up shortly.

Meanwhile did you try the ‘Quick instructions’ at the top, steps 3 to 6?

Hi again. I got a bit confused by the video demonstrating heavy, which showed a completely different compilation process. No matter, I had no trouble with the steps described and everything is working fine now - including the docs.

It seems to me quite an unusual process to get pd patches on to your device, but I’m very impressed that you found such a user-friendly solution. Nice work, this must be hugely popular!


Thanks, yes the OWL is unique in this respect. Glad to hear you appreciate it: help spread the word!

ps I’ve updated the PD template, it’s much simpler now:

Basic build instructions are now also available in the Documentation.