I have 2 DS18B20 sensors ready to go into the Fridge / Freezer, the problem is, how do I actually get them in there for a nice clean, permanent installation?
Everything seems to be pretty well sealed, can you guys share how you did this? Also, I’m sure there are already sensors built in, is it worth looking at taping into those sensors and integrating?
Thanks
If you are feeling adventurous you could drill through the fridge to the outside world and hope not to hit anything on the way through!
On a serious note, there is surely a way to run the probe cables through near where the internal light gets powered.
Yea, I was originally thinking the drain, ill just run them down the drain but its like 10mm exit hole on the outside,
So, i,m a little confused and stuck,
The whole back of the fridge looks like its sealed (with a cover) and only the bottom where the compressor is is accessible.
The DS18B20 cable is much smaller though, can you not get it through?
A little trick for getting wires / cables through pipes:
I’ve pulled very large cables through conduits over 100m long using this method.
Hmm yea, it has like a filter attached to it too before it enters the drip tray
It’s a very useful automation when combined with an alarm - after having a freezer with 40kg of meat spoil and not noticing it for weeks, that’s something I really want to avoid happening again.
Method 1: Drill through from the outside and insert a onewire type sensor.
I wrote about doing this here: https://digdilem.org/2022/12/one-wire-temperature-sensors-and-home-assistant/
Method 2: Adapt a Aqara or similar button-battery temp sensor to run off a 18650 cell. These last for months in -20c freezer temps, whereas a button battery can last days to a few weeks. The wrap everything in a plastic bag and just pop it inside the fridge or freezer. No drilling required.
Pics and description: https://digdilem.org/2022/11/measuring-temperature-inside-freezers/
If you drill through the fridge nice and close to the door edge (ie: right on the bend of the steel) you should be safe to not hit any refrigerant line.
Where I put a red dot.
Can you get the cable to exit the drain pipe prior to the filter? Even if it means drilling a cable hole in the pipe.
The thing is, I cant drill, its not my fridge.
Remove drain filter altogether?
Otherwise I think wireless is going to be your only option other than having the cable goes past the door seal. You could use individual wires at this point so they sit flatter to the fridge steel (rather than a larger round cable).
It’s not a very good idea to “plug the drain”. You”ll get water pond inside pretty quickly. Drain is there to …well, drain the water from inside… 
If you could remove back plate (i guess it’s only screwed…?) you could find where cable for light and original sensor is drawn inside.
I will try this, however the back did not look easy to remove.
Using sealed DS18x20 cabled sensors, I found the flexible door seal didn’t conform around the cable well enough leaving a small airgap. This was just enough for water to condense and freeze.
A 3d-printed wedge-shaped shim to smooth out the surface might fix this.
Bad ASCII-art diagram:
/|O|\
================
Triangular wedge, cable, triangular wedge.
Use something ZigBee or Bluetooth.
Hmm I would prefer to stick with esphome, as everything I have is esphome.
There must be a way to get these sensors in there, but its not easy.
Many Bluetooth things can be incorporated with esphome.
True,
So BT on the esp32? with a battery? In the freezer?
I’ll try and test again tomorrow. I know I have got temps from inside my fridge. Can’t recall how.
Damn if I could just remove the back cover of this fridge im sure I could get these sensors in there somehow, its like a science project just to get access behind this rear panel.