ESP32 Powered Crunch-E Makes Beats on the Go
There’s no shortage of devices for creating electronic music, but for beginners, the cost of synthesizers and drum machines can be daunting. Fortunately, if you have a well-stocked parts bin, you might already have most of what you need to build your own Crunch-E.
Crunch-E: A DIY Music-Making Platform
Described by its creator Roman Revzin as a “keychain form factor music-making platform,” the Crunch-E combines several key components:
- ESP32 microcontroller
- MAX98357 I2S audio amplifier
- Array of tactile buttons
- LEDs and passive components
You can assemble it on a perfboard using off-the-shelf modules, or for a more polished look, you can design and fabricate a PCB. There are even plans to offer pre-built Crunch-E units in the future.
Hardware Flexibility
The Crunch-E’s hardware setup is quite flexible. As long as you have the major components and can run the provided software, the exact implementation can vary. This allows for creativity and customization in the build process.

CrunchOS: The Heart of Crunch-E
The software, called CrunchOS, currently offers:
- Four tracks
- Ten synth instruments
- Two drum machine banks
All functions are accessible via a 4 x 4 button array. A “cheat sheet” in the documentation helps users understand the default configuration of each key. The demo video showcases the impressive capabilities of this platform, and it’s clear that this is just the beginning. As more users build and experiment with their Crunch-E hardware, the software is likely to expand and evolve, offering even more features and possibilities.
Check out the demo video below to see the Crunch-E in action and get inspired to start your own build.
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