Figure 1. Deepstomp prototype assembled in double side PCB and put in a plastic enclosure (left), and assembled in single side matrix PCB without enclosure (right)

Platform and Development Tools Download

Deepstomp is an open-source DIY digital multi-effect stompbox platform. It is based on STM32F1 32-bit ARM Cortex M3 from STMicroelectronics (72MHz CPU clock, 20kB RAM, and 64kB non-volatile flash memory). This complete platform has been published in a public repository, and can be downloaded at The hardware design is only available as the circuit’s schematic diagram only, and you are free to design your own PCB (printed circuit board) for the circuit assembly. The software package is a complete project files of SW4STM32 (System Workbench for STM32) development tool. This development tool is free, and can be obtained (with free registration) here. To load the compiled firmware to the Deepstomp stompbox, you need to use serial bootloader that can be obtained from STMicroelectronic here (with free registration).

The Most Wanted Deepstomp’s Features

We can list many features of Deepstomp platform, but here we select some of the best features you probably want them most:

  • Low cost, everyone love it 🙂
  • Programmable, so you can change the effect type by reprogramming the firmware.
  • Pluggable processor module board, hopefully you’ll find cheap unique effect in a protected core to buy, or you can even sell your custom protected special effect at lower cost and higher margin.
  • True real-time (non-block processing), fixed processing delay as 1 sampling period (1/44100 s).
  • Supports 15-bit input conversion by employing multi-channel expansion oversampling method.
  • Supports 16-bit output conversion by employing double cascaded 8-bit PWM with automatic calibration.
  • Support guitar (or general musical instrument) tuner with (+-)1/12 semitone precision (+-0.46 % frequency deviation)
  • Supports single-effect and multi-effect mode with full parameter control and preset management by the system core for easy programming, enable focusing the effort on the effect’s signal processing.
  • Supports up-to 6 controllable parameters for single effect mode.
  • Supports up-to 10 single effect modules for multi-effect mode, 4 controllable parameters for each module, any module with more than 4 parameters can be easily extended to provide full control.
  • Supports up-to 19 customable presets for multi-effect mode’s parameter control, manage all the process of loading, storing, and the factory default resetting.
  • Current implemented open-source effect modules: expansor (integrated noise-gate expander and compressor), distortion (with overdrive and fuzz type, plus hi-low tone control), and digital delay. Other common digital effect modules are under development and will be available soon.

How Deepstomp DIY Works for Everyone

  1. Build the hardware if you’re a hardware geek, or buy the built hardware if are not or too lazy.
  2. Code your custom effect and compile to binary if you’re a software geek, or just skip this step if you are not or just don’t wanna do it.
  3. Find your desired compiled effect application binaries in the open source repository folder or from your own development folder. If you find one then flash it to the stompbox and go to step 5.
  4. Find a pluggable processor module board from third party vendor who develop their protected proprietary effect algorithm, buy it and plug it to the Deepstomp’s main board.
  5. Play end enjoy it 🙂


  • Each source code files in the software package has its own license in its copyright notice at the top of the source code, which we believe that they has the most flexible open-source licensing, that allow everyone to use them for their proprietary commercial product, not limited only for open-source products. Please let me know if there’s any file in this distrbution has any limiting license that prevent anyone to use it in non open-source project/product by contacting me at my email: hamuro at vidisonic dot com.
  • The Deepstomp’s hardware design (Deepstomp’s main board circuit) can be used in any commercial or open-source product, with or without modification. Everyone is allowed to produce Deepstomp hardware under their own brand or trademark.