The SquishBox is a synthesizer in a guitar pedal. It has 4 USB ports for you to plug in MIDI keyboards/controllers or upload new sounds, stereo 1/4″ outputs to your mixer/amp/headphones, an LCD display, two buttons for switching between patches and changing settings, and wifi for you to upload sounds and edit patches.

As a keyboard-playing musician, I love being able to use software instruments to produce any sounds/effects I want, but to use them you usually need a tablet or laptop, an audio interface, and extra cash to buy DAW software and virtual instruments. Also, you have to drag all that stuff on stage, set it up, and be poking a screen or tapping keys while you're trying to play - which does not, to my eyes, rock. What is needed, I decided, is a sound module that fits in a cool guitar-pedal-type box, has some buttons you can stomp with a foot or smash with a fist to change patches and settings, and a little screen to tell you what it's doing.

So, I made the SquishBox, a Raspberry Pi 3 B+ computer tucked into a Hammond 1590BB aluminum stompbox that runs the versatile, open-source, and free FluidSynth (hence the name - that's what happens when you stomp on a box full of fluid) and uses soundfonts - a widely- and freely- available and editable software instrument format - to produce whatever sounds you want, in whatever way you want. It's designed to use inexpensive, easy-to-find parts but still sound great, and be fairly simple to understand and modify, so you can own your sound!

The SquishBox comes in 5V- and 9V-powered versions and includes an appropriate power supply. The 5V version is standard and provides the most power for USB controllers and add-ons. The 9V version can be powered from the kind of power supply often used in a guitar pedalboard (i.e. 9V center-negative), but can't draw as much current, so you may not be able to plug a controller into all 4 of the Pi's USB ports at once. For additional information, support, and tips on customizing your SquishBox, visit Geek Funk Labs!

Fully assembled version features:

• 2 stomp switches
• 16x2 character LCD
• 4 USB inputs to connect MIDI keyboards/controllers or other devices (e.g. 5-pin MIDI->USB connector for legacy devices)
• 2 1/4" outputs for line out or headphones
• 24bit 192kHz stereo audio
• Onboard WiFi with web interface for configuration/uploading additional soundfonts
• Cross-platform software for editing patches and banks from your computer