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Comment by dougdonohoe | Hacker News Reader

Feel this. I don't even use Alexa, Siri or Hey Google in my house. My fridge is a fridge and not wifi enabled.

I WiFi enabled my fridge because the thermostat broke. So now an ESP32 with a dallas temperature sensor and a relay take care of that. The code on the ESP32 is smart enough to keep working if there is no internet (wasn't always like this, until it had to), but it still sends the temperature to the server for logging and the server can send it configuration commands or control the relay directly, as it was initially.

It was a great way to keep the fridge alive, the thermostat was already a replacement and it never worked properly, so that sometimes things were frozen, sometimes barely cold. ~24 years old. A new one would be more efficient, but then I woudln't be able to log when I opened the fridge anymore (only with something battery powered and long transmit intervals).

This is awesome, great way to keep a fridge going! Temp sensor to ESP32, ESP32 monitors set point and calls for cool, output from ESP32 energizes relay coil which turns on the compressor?

> A new one would be more efficient, but then I woudln't be able to log when I opened the fridge anymore (only with something battery powered and long transmit intervals).

Also, how did you do this? Wiring to the door switch itself or a current switch around the fridge light conductor?

i also have questions. was the fridge "smart"-capable prior to the esp32 mods and you just replaced the factory controller with your esp32 stuff, or youre saying you wired in the appropriate circuitry to replace the pressure-controlling thermostat with your esp32 stuff?

it was not smart-capable. I was very lucky that the thermostat was in the fridge itself, above the compartments. There I removed the old analog control and had enough space to fit a USB power supply to the cables which were there connected to the now-removed analog control. I was lucky. The sent data gets stored in InfluxDB. So with Grafana it allows me to see when I opened it, because the temperature rises immediately.

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