I've started on a project to make my own DCC decoders, with the aim of getting much cheaper sound capability on locomotives than buying sound-fitted ones or paying for commercial sound decoders. It will take me a long time to reach that goal, and I might fail, but I'm going to try.
In this video I make a start by getting an understanding of the most basic elements of the DCC control signal, connecting a Raspberry Pi Pico microcontroller and writing some code in Python to capture and interpret the signal from the tracks.
I've spent a lot of time making visualisations to explain what I've learned about the DCC signal - hopefully you'll find it interesting, maybe even useful if you decide to embark on a similar project.
The electrical bits I bought for this, or which I already had and used in the video:
Voltage Regulators, LDO 3.3V
https://cpc.farnell.com/stmicroelectronics/lf33cv/v-reg-ldo-3-3v-to-220-3/dp/SC08293
Schottky Diodes
https://cpc.farnell.com/stmicroelectronics/bat48/diode-schottky-small-signal/dp/SC07328
Raspberry Pi Pico, with headers
https://thepihut.com/products/raspberry-pi-pico?variant=41925332566211
Digital multimeter
https://www.railwayscenics.com/duratool-hand-held-digital-multimeter-test-leads-p-3492.html?sort=1a&cPath=20_28