- Four stereo inputs and one mute circuit, switched with Panasonic TQ-2 relays
- One stereo output
- Controlled with ESP32
- Space for the ESP32S/NodeMCU, with break-out for all pins
- IO pins go high when activating a relay, can be used for indicator LEDs
- Power/GND for ESP32 and relays separate from signal power/GND
- Fully open source, no strings attached
Schematics, Downloads and other resources
- ESP32 Eagle library: https://hackaday.io/project/46280/log/87314-esp32s-devkit-eagle-library
- Schematic (with ESP32): https://hackaday.io/project/46280/gallery#a3e1b4be8cf593af3733282c43617b2c
- Schematic (without ESP32): https://hackaday.io/project/46280/gallery#cbabb3ed6913ae0336a70ea0561f796d
- Component list: https://hackaday.io/project/46280-muffsy-stereo-relay-input-selector#menu-components
- Mouser Shopping Cart: https://www.mouser.se/ProjectManager/ProjectDetail.aspx?AccessID=ff6d49ef76
- Eagle project files and Gerbers are available in the files section.
- Simple example sketch: https://hackaday.io/project/46280-muffsy-stereo-relay-input-selector/log/136019-simple-sketch-switch-between-relay1-and-2-every-4-seconds
- Github Project Page: https://github.com/muffsy/relayboard
The ESP32 connects to your wireless network and presents a web page where you can control the relays. It also has an HTTP GET API in case you'd like to make your own web page controls.
The ESP32 module used for this project is the one called ESP32s NodeMCU. It's got 2x19 pins, no pin labels on the top, and a white bottom side with the text "NodeMCU ESP-32S v1.1"
The ESP32 development kit has a CP2102 USB to UART bridge, drivers are available from Silicon Labs:
Information on how to program the ESP32 using the Arduino IDE is available from Espressif. The board name in the Arduino IDE is "NodeMCU-32S", as it says on the backside of the board:
Espressif's "IoT Development Framework" IDF/SDK is available here, along with a lot more information: