An unlucky consequence of the fast improvement of expertise is the fast tempo at which digital gadgets turn out to be out of date. We regularly see very well-made {hardware} find yourself coated in mud inside just some years, as a result of the underlying expertise is now not related. To avoid wasting that high-quality {hardware} from the e-waste mountains of the world, many manufacturers get artistic and switch to upcycling. That’s how bitluni was in a position to revive a classic audio management panel as a contemporary ESP32-controlled music sequencer/synthesizer.

Whereas attending the Hackaday Supercon in California this 12 months, bitluni visited the Apex Electronics Surplus retailer in LA. That retailer has an enormous number of outdated digital gadgets and elements, the place bitluni discovered a management panel from a ‘90s audio workstation. That will have been a really high-end workstation for skilled audio engineers that contained a number of of those management panels. Every panel has 16 rotary encoders in a 4×4 grid. Each encoder has its personal four-digit VFD-style show and mode button with LED indicator, and the encoder knobs even have an outer ring of LEDs to point out quantity, amplitude, depth, or the rest. Lastly, each column has a keypad on the backside with 12 buttons, every with an LED indicator.

That’s quite a lot of good {hardware} in a compact interface, making it fairly fascinating. Bitluni and a pal at Hackaday each began reverse-engineering the gadget, with that pal (Jeoen Domburg, AKA “Spritetm”) unlocking all the pieces by getting access to the FPGA (Discipline-Programmable Gate Array) controller. With that entry, bitluni was ready to make use of the controls nevertheless he preferred.

To realize that, bitluni designed a customized PCB that plugs into the management panel’s bus interface. That PCB comprises an ESP32 microcontroller that reads button presses and encoder positions, and likewise units the shows and LEDs. He selected to make use of the ESP32 to create a synthesizer/sampler sequencer that makes use of the knobs and buttons to play both synthesized tones or sampled WAV information in repeating patterns. The ESP32 outputs audio as 1-bit, as a result of many of the microcontroller’s pins have been wanted to interface with the panel. The standard isn’t nice, nevertheless it has a pleasant lo-fi sound that’s interesting for sure music.