Channel strip: hardware selection!
This is just an info-dump for me to keep reference. Read at your own risk!
This post provides the background motivation, high-level timeline plan, and a list of the hardware elements. The next post will detail how each of the microcontroller's pins will be allocated to controlling the peripheral devices.
Motivation
Modern digital audio mixing console hardware designs are trending ever more to abstract touchscreens and massively multi-function controls. I strongly dislike this trend, and my intuition and rudimentary understanding of Human-Computer Interaction from my university degree leads me to believe that it is actively less productive.
The rise of "maker YouTube", where self-taught people of all ages and stages create the specific thing that they need, has inspired me to do likewise (alongside my high-school experiences).
I recently saw a series of videos where a person reconstructed and restored an old digital broadcast audio mixing console, which exensively incorporates touch-sensitive controls, and also lovely 7-segment displays and discrete LED bar meters.
Plan
All good projects need a plan, so here's mine:
- PoC: One of each element, on a first-go rough PCB layout
- Full-scale: The full design, on a full-size PCB layout
- RC: The full design, refined and compacted to scale out to multiple adjacent channel strips
- Bank: A full 8- or 12-channel strip bank of units?
Hardware
Naturally, this requires a good deal of electronics hardware. The centrepiece shall be the ESP32-S3 microcontroller, purchased from AliExpress (pinout).
Power is supplied using USB-PD over a USB-C connection, at 12V, using a daughterboard from AliExpress.
Power is regulated to the motor controller using a 7810 from AliExpress, and regulated to the ESP32 using a 7805 from the same.
The motor for the motorised fader will be controlled by a DRV8833 on a daughterboard from AliExpress.
The motorised fader itself is a high-quality Alps unit, the RSA0N11M9A0J from AliExpress.
The rotary encoders will be the the standard KY-040 units from AliExpress.
The backlit ON momentary button is a PB26-13M-E from AliExpress.
The backlit CUE momentary button (and page buttons) is a TS26-2 from AliExpress.
The digital scribble strip display is a 1.5" OLED unit, controlled via SPI from AliExpress.
The encoder LED bar meters will be 10-segment yellow-green units from AliExpress.
The main LED bar meter will be a sequence of four 10-segment units from AliExpress: the top one is 50/50 red/yellow, the second one is all yellow, and the bottom two are pure green.
The dynamics LED bar meters will each be a 5-segment unit from AliExpress.
The buttons and LEDS will be accessed via 23S17 SPI-based I/O expanders from AliExpress.
The channel colour will be provided by a discrete 5mm WS2812-based LED from AliExpress.
The +48V phantom power LED (and page LEDs) is a standard 3mm red diode from AliExpress.