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ESP32 based ethernet I/O board for home automation compatible with ESPHome, Tasmota, etc.


  • wide range of input voltage 6-28V
  • 4x opto-isolated "fast" operation inputs (connected to GPIO)
  • 16x opto-isolated general inputs (connected to MCP23017 expander)
  • 2x PWM capable low-side fully protected switches (connected to GPIO)
  • 16x low-side fully protected switches for switching the non-latching relays or SSR relays (connected to MCP23017 expander)
  • daisy chain design - see below


Basic wiring

Wiring 1

"Fast" inputs

Are meant to be used for reading pulses from utility meter ie. power meter with S0 output Wiring 2

Daisy chain design

Should you need more inputs/outputs (up to 96 more inputs/outputs or combination thanks to changing the address of MCP23017) you can use the same PCB. Just don't populate ETH breakout board and ESP32 and solder AMS1117-3.3 with its capacitor. The boards will be connected via SDA/SCL but thanks to a bus buffer (P82B96) communication can easilly be made up to 20 meters (possibly more by reducing speed of I2C bus)!

In this mode the "slave" device can't make use of S0 inputs nor the PWM outputs

Wiring 3

For more information please visit wiki

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