The OWL: a programmable guitar pedal

A team of Hackspace and Music Hackspace members are currently working on a programmable guitar effects pedal called the OWL. OWL stands for Open Ware Laboratory, which refers to the fact that the entire project is open-source in both hardware and software – all code and documents relating to the project will be freely available under the Gnu GPL license.

The OWL is based around an ARM Cortex M4 chip, and can be programmed using a specially developed software framework. The audio processing code takes the form of patches, which are written in C/C++ using a simple API. There is also a project called OwlSim which allows you to run the same patches as VST and Audio Unit plugins. This means that you can test your code in your favourite DAW/host before uploading to the pedal, or just have some fun building plugins with an easy-to-use C/C++ framework. A bunch of patches have already been written and are ready to be tried out.

The team ran a Kickstarter campaign last month to raise funding for a first production run of the pedal and raised more than £33,000 (over 400% funded of the initial £8000 target) in pre-orders. They found it hugely encouraging to see that there are a lot of people out there who are enthused by open-source programmable hardware. Currently the design is being finalised, with production scheduled to start in August.


For more information, check out the project website at, and if you are interested in getting involved in some capacity (this could be web management, PR, patch development, coding or hardware assembly) they would like to hear from you – send them an email at