ESP32 and PWM

I'm continuing reinventing wheels with my ESP32. In ESP32 and Mozzi I was using the built-in DAC for audio output. In this post I'm taking a detailed look at how to use PWM for audio output instead. Part 1 - All the theory and research around PWM and the ESP32. Part 2 - Generating different waveforms on …

ESP32 and Mozzi

I've been meaning to do something with the ESP32 for some time. I have some general ESP32-C3 devices, and a range of XIAO ESP32 (S2 and C3) devices too, but what I was particularly interested in was the original ESP32 as it includes two 8-bit DACs. This is my first set of experiments using a …

Diagnosing and attempting to fix a Yamaha DX100 – Part 2

At the end of part 1, I've established that the basics all seem ok (PCB, interconnections, power) and that basic digital logic stuff is happening. I rounded off my write-up with the following ideas for what to investigate next: Get some proper triggering from the chip enables to check for valid data signals. Check out …

CD Rack Format Zynthian – Part 2

I've recently updated my "CD Rack" box to a horizontal black box, still shaped for my "CD Rack" format modules. But as it is black, and I've a black TX816, I've rebuilt my CD Rack format Zynthian with a black, PCB front panel too. Original Design Notes: CD Rack Format Zynthian. Warning! I strongly recommend using …

Arduino Direct Digital (Additive) Synthesis

This is actually a collection of previous projects with the code tidied up a little and combined to show a single sketch that can be configured for either PWM, an R2R ladder or the MCP4725 I2C DAC. There isn't really anything here that hasn't been talked about before somewhere, but hopefully this can act as …