Software Update/InstallDownloadsDetails

I sell on Tindie

The SquishBox is a synthesizer in a guitar pedal. It has 4 USB ports for you to plug in MIDI keyboards/controllers, stereo or headphone 1/4″ outputs, an LCD display, and two buttons for switching between patches and changing settings.

The SquishBox is designed to be inexpensive, easy to understand and modify, but still sound great. The brain of the SquishBox is a Raspberry Pi computer with an add-on sound card for high-quality audio. The sound engine is FluidSynth, an open-source software synthesizer that uses soundfonts, a versatile and widely-available sample-based sound format that can produce instruments from growly synths to perfect pianos. The interface is FluidPatcher – code written by Geek Funk Labs that allows you to create your own patches/banks, and even change the interface. You can buy one as a kit or fully assembled on Tindie.

Software Install/Update

The SquishBox comes with software preinstalled on its SD card. Recent models can be updated using the “Update Device” option in the System Menu. To update manually, remotely log in to the SquishBox and enter the following at the command line:

curl -L git.io/squishbox | bash

The script above can also be used to install the SquishBox software on a blank SD card. First, install the Raspberry Pi OS using an operating system image from the Raspberry Pi Foundation‘s website. Then run the script above and choose your preferred options.



Schematics and a list of parts can be found in the Assembly Instructions above. The design files for the PCB can be downloaded from OSHPark. My project on Hackaday will show you how to build the SquishBox without the PCB, on single-sided perfboard. The source code for the SquishBox is publicly-available on GitHub, and includes a wiki explaining the API so you can modify or create your own interface.

The soundfont file format has been made publicly available, and as a result lots of software can use them and they’re widely available, both for purchase and free of charge/licensing. The quality of soundfonts available varies widely, and one person’s specific needs may differ from another’s, so I recommend searching out and trying as many as you can. The SquishBox comes with a healthy selection of free soundfonts, which you can also download in the soundfonts collection above. You can also easily modify soundfonts – not just the raw audio samples, but how they are played and even how they can be modulated by your controller – using various editors. I highly recommend Polyphone for this purpose. You can even create your own soundfonts from scratch!