EmonHub MQTT to GPIO

GPIO port control by threshold in temperature

As I understand it, the signal from the temperature sensor goes via the EmonTX to the EmonHub via MQTT (at least that’s what I see in the log) and is sent by the EmonHub to EmonCMS.

It is also possible to have the RaspberryPi switch a GPIO, that is well known.

Now I would like to have GPIO 17 switched on using the MQTT of the temperature. I’ve read a lot but I’m not out yet.

It is my intention to set off a buzzer (GPIO 17) for 30 seconds if the temperature exceeds a certain value (TempH).

It looks like this.

  • GPIO 17 gets voltage at a fixed temperature (TempH = 60ºC) and after 5 seconds automatically becomes powerless.

  • GPIO 17 may only become active again after the sensor has dropped 10ºC in relation to the set temperature (TempL = TempH - 10).

  • I connect an Optocoupler to GPIO 17

  • Optocoupler switches on a delay relay when live

  • Delay relay switches buzzer on and switches off after 30 seconds.

I would like the actions that are done to be visible in EmonCMS as well and to be stored in a CSV.

Who can help me with this?

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Hello @P49 sorry it’s not something I have done before, you might be able to do the logic control side of things with NodeRed. See:

Node-RED - Guide | OpenEnergyMonitor

and perhaps:

Control Raspberry Pi GPIO using node-RED – E-Tinkers