Eurorack CV to DMX Stage Light Controler

August 8th, 2024



“A module that allows me to line in triggers or audio sources to a channel and then have that change act basically as a gate to turn various lights on and off. That way the lights aren't really tied to an sound spectrum but rather the parts/instruments I assign to each channel.”


A Control-Voltage to DMX converter eurorack module


...Is what Anthony described to me at Fire Lights Music festival this summer.


Eurorack CV to DMX Module Block diagram
Eurorack CV to DMX Module Block diagram

November 11th, 2024 - Layout Design



There are two ways I can take this


Option 1) Few inputs, Small HP, chainable


- Lower cost per unit, but vastly more expensive if users want to have more outputs

- Lower bar to entry with only a few CV inputs for a few lights, wider market.

- Smaller HP width → larger market


Designs 1,2, and 3 follow this idea with a minimal footprint but limited Functionality


Option 2) Many inputs, largeish HP, Skip the chainable SW


- Lower cost for many inputs

- Probably less work to design, no need for chaining.

- How many inputs are actually useful?


Design number 4 boasts 8 CV inputs that can alll be maped to a singel DMX Universe. The design is not very visually appealing, but that can be fixed.

Eurorack CV to DMX Module V0.1
My first attempt at designing the layout
Eurorack CV to DMX Module V0.2, V0.3 and V0.4
Layout design ideas 2, 3 and 4


I'd really like to try using an ESP32-S3. However this microcontroller is likely way overkill, and significantly more expensive than the tried and true AtMega328p. The ESP also takes up more real estate requiring external flash, and an additional 3.3V power regulator.

But, If I build my own confidence in ESP, then I have a MUCH faster, more powerful microcontroller for larger more complex projects. 20 ADCs! Using only 4 for the CV-DMX seems like a waste of power, especially if I want to make this module chainable.




November 23th, 2024 - ESP32-S3 Implmentation


Today I began implementing the code onto an ESP32-S3. Made a nice 3-channel proto board on the back of an old VCO front panel. The ESP reads the CV value and outputs some sort of digital data. The DMX light does not yet respond to the signals. Looking at my notes from 20241113, it seems I need to pull the TX line high. Will try this later tonight. I am guessing that my circuit is bad. The code compiled fine once I updated the platformio.ini configuration file.

  1. Get better with the ESP32-s3.
  2. Satisfy my craving for Eurorack controlled leds
  3. Determine if eurorack controlled leds are fun
  4. Determine the number of IO required for max fun.
  5. And If I find the design to be useful, practice implementing an ESP-S3 onto a custom PCB. This way I can more confidently pursue ESE projects that require higher computational power.


November 24th, 2024 - ESP32-S3 Implmentation


- Pulled the RX line high via a small resistor.

- Turns out the DMX A/B pins are NOT reversible. You must get this right--> Make it adjustable on PCBs.

- May still need smoothing caps on input. Blinking Red light occasionally turns on green if I have the attenuator turned all the way up. This could also be due to an overflow error.

- I am also finding that a full 512 DMX slots takes just enough time to make audio-syncing feel a bit off-wack. Trimming it down to, say 16 slots perfects musical clock-to-light syncing for even the highest BPM



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