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For this solution, we are using a Sonoff SV controller. This is a nice controller since it has everything we need to control the heater's remote relays. Additionally, we can power it from the heater itself since it accepts 5-24 volts input and the heater will supply us with 10v. We are going to use the Sonoff SV in isolation mode by removing the two resisters that would normally supply the power to the controller using the input voltage.

Wiring

Wiring Diagram

Wiring Pictures

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Temperature Sensor

We are going to add a temperature sensor to the heater so that we can turn the heater on or off based on temperature.

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• Use the dimple to center the drill bit. Drill a 1/4 in (6.4 mm) diameter hole through the port. Take care not to damage the plastic threads. TIP: Drilling a 1/8 in (3 mm) diameter hole first will help prevent thread damage
• Wrapped 5-6 turns of PTFE (Teflon) tape around the male threads of the adaptor.
• Thread in your 1/4 inch adaptor into the port. Make sure to get a snug fit. Do not over-tighten.

Firmware

We used custom firmware for our solution.

... more to come... 

Homebridge Configuration

Using the mqtt-thing homebridge plugin, add the following configuration:

The result:

Image Added

References

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