F373 Mod - a Euro-Rack DSP technology demonstration.

F373 Mod Front F373 Mod Back

f373 Mod - fully assembled

What is it?

This is a 10HP Euro-Rack format module with 2 Audio/CV inputs, 4 CV inputs, 4 pots, 2 Digital (Sync) inputs and 2 Audio outputs. It features a 128x64 monochrome OLED display, two buttons, a rotary encoder with pushbutton, a micro SD card slot, a hidden USB mini-B jack, RGB LED and I2C EEPROM.


The STM32F373 MCU is a fascinating hybrid Analog/Digital processor with a unique combination of features that I've wanted to try out as a platform for audio DSP. Included are a set of 16-bit Sigma/Delta ADCs, as well as 12-bit DACs that are almost ideal for audio synthesis in a single package. I've been able to port a number of my audio effects algorithms over and they run nicely.


Software Development

The STM32 family of parts are supported by a variety of commercial IDEs, all of which are available in low-cost or limited free versions from the ST website.

I prefer to use open-source tools so I've set up a development environment based on the GNU C compiler for ARM, available for free from the Launchpad project. For downloading to the target I use OpenOCD and the ST-Link V2 SWD interface that's available on most all of the inexpensive STM32 Discovery boards. To accelerate development I also use the STM32 Standard Peripheral Library as a starting point for my code and then optimize out the heavyweight functions as required. Links to all of these are here:

Design Resources

Project Status

Design Notes

I threw a lot of extra goodies into this design just to check out practicality. Some of them worked, some of them didn't. Here's a rundown:

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Last Updated
Comments to:
Eric Brombaugh

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