Looking for helpful folks that could help me to create come Gerbers, why the Roon Tinkering forum I hear you ask…
I want to use a Olimex ESP32-POE MCU and connect that through a ULN2803A to six G6K-2P relays and 22 resistors, to make networked relay volume control for under $100. I want to solve this pesky lack of useful USB volume control (for DSD) on the majority of (affordable) DAC’s.
RCA L/R pair in one side, through the R2R network to another RCA L/R pair at the other side, it could be inline on your DAC output cable, and a LAN cable giving PoE, you could also power and communicate with it some other way, it supports battery and has a LiPo charge circuit, USB, BLE, WiFi…
It’s a hobby project, in saying that I don’t expect it done for nothing, happy to pay a bit.
In theory I set the six GPIO’s in the correct sequence to set a specific volume and to query the volume I read the GPIO’s.
I’m thinking I might be able to use ESPHome on the ESP32 to read/set the GPIO’s from Home Assistant. It should be trivial to somehow integrate it with Roon.
Essentially I want to put the ESP32-POE into a socket on the new board, six of it’s GPIO’s will go to the ULN2803A inputs and the outputs go to the relays. Using PoE I should have at least 600mA @ 5V remaining for this circuit.
Attached is the main part of the circuit, grabbed from some doco and gerbers I found online http://www.vaneijndhoven.net/jos/attenuator-calculator/index.html.
I can surface-mount solder, order parts from DigiKey and get boards made at PCBWay but I’ve never done a Gerber.
Thanks for looking.