It is based on a Sonoff Basic and two DS18B20 sensors. I will not go into configuration details now, because all of this has already been discussed in other places. See:
I chose this solution at the time because (1) I had a Sonoff lying around and (2) it was a quite cheap and quickly set up solution. The big disadvantage is of course the need for an external power supply. How I solved this issue can be seen in the pictures below. In the fridge part I was able to go through the “dripping hole” in the back, in the freezer part I had to go through the door insulation. With proper preparation this method seems to work without issues or leakage.
The solution above is fun but what you really want is a battery-powered radio transmitting device with a temperature sensor.
Mi Flora
One especially clever solution I’d go for nowadays is to abuse the Xiaomi Mi Flora Plant Sensor. Yes it’s supposed to gather data from a plant but the temperature (and light) sensor also work without being stuck in soil See here for more: Xiaomi Mi Flora Plant Sensor MQTT Client/Daemon
openHAB Rule for Temperature Summary
A simple rule is responsible for the Basic UI Sitemap view as seen above:
rule "Fridge Summary"
when
Item Kitchen_Fridge_TempCooling changed or
Item Kitchen_Fridge_TempFreezer changed
then
Kitchen_Fridge_TempSummary.postUpdate(
String::format("%s °C / %s °C",
Kitchen_Fridge_TempCooling.state, Kitchen_Fridge_TempFreezer.state
)
)
end
Hello,
I’m using a sonoff basic to monitorize the temperetures of my fridge and freezer. All works well. Then I’ve made the following declarations:
Rules file:
rule "Fridge Summary"
when
Item SonoffBasic1_Temp1 changed or
Item SonoffBasic1_Temp2 changed
then
Fridge_TempSummary.postUpdate(
String::format("%s °C / %s °C", SonoffBasic1_Temp1.state, SonoffBasic1_Temp2.state)
)
end