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.
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.
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.
November 24th, 2024
- 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
November 30th, 2024
I'm thinking of adding a 3+ digit 7-segment display to the CV-DMX front panel using side-sticker LEDs diffused through the FR-4 PCB. Same concept as the Quad ADSR ring lights, but diffused, and displaying numerical values instead of rings. The Quad ADSR uses a MAX7219 LED Driver IC, which is designed for such applications. In fact, the C library I am using happens to have lookup tables for converting ASCII characters to LED values on the MAX7219.
Setting the DMX channel will be done with a Rotary Encoder. Short press the RE knob to toggle between CV inputs, turn the knob to select DMX channel. It would also be cool to send 1 CV input to multiple DMX channels. That way a RGB light can flash or fade white by sending a single CV signal to a single CV input. OR you could sync multiple light fixtures to a single CV.
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