I use the Inkbird sensor inside my refrigerators ( 1 for freezer and 1 for refrigerator). They use 2 AAA batteries. I link them to an esphome Bluetooth proxy. No drilling
But being battery, how often do they update? Surely they cant update too often?
I do have one of these kicking around.
Inside a Faraday cage? 
The Wireless Tags devices actually do pretty well getting through the fridge (my deep freeze has always been a bit more iffy with them).
One of the issues, aside from signal, that you are probably going to hit is the temperature and condensation - most electronics arenāt going to like either. The Wireless Tags have a coating on them to help. You can add a coating to your own electronics to help as well, but I think you have an uphill battle trying to make a lot of stuff work inside a metal box.
Seconding (or thirding) BT temp sensors. I have tons of these (bought for $4 apiece on Ali). They work great and the battery lasts quite a while. Obviously shorter life in the freezer, but still multiple months at minimum. Using BT Proxy on the ESP makes pulling them into HA easy too.
You have that entire LCD in the fridge and freezer? Thatās pretty interesting, I have devices similar to that on Zigbee and never thought to even try it, figuring that LCD would go south pretty fast.
Yep, although it might display a little funny? Honestly never paid attention since Iām just using it as a sensor. Iāve tossed them several places that I figured they might die prematurely (but didnāt really care since theyāre so cheap) and theyāve always worked and kept giving reliable readings.
I believe at least once an hour, unless there is a temp change over 1 degree ( I believe). Could not find the spec for this. The faraday cage issue mentioned above has never been an issue. I have the esp32 device plugged in close to the refrigerator. I use this for regulating the freezertemp in the winter. If the freezer goes above 3F I turn on a light bulb in the refrigerator. This happens as refrigerator is not rated for garage use (another unacceptable design).
How do you route the probe into the fridge/freezer? Iāve considered this as well and, without compromising the seal or something, the only way I can think is to needle a wire through where the control board is on the back up into the head of the fridge, then I could get least get close enough to the liner to take a reading that could be adjusted.
Hey Dean, I love this thread as I did exactly this a couple of years ago. Has aided me well over the years. Adopting temperature settings, the occasional ādoors left openā alarms. Cool nerd stuff!
I did use two DS18B20 just as you did. For discussed reasons I did not want to modify the fridge in any way. I did feed in the two cables through the front door seals. Would have to search for a picture. I did remove the outer insulation around the door and modeled a smooth transition with putty (UHU | patafix weiĆ). The goal was to create an even dent that would still leave no room for seal leaks with a closed door. The last step for me was to mask everything with white tape. The result is elegant and inconspicuous.
Btw be thoughtful about the sensor location. You want them exposed to an open door, not be completely affected by a new item put in (still warm), and not in the way when moving stuff around.
Hope this helps. Cheers!
Interestingā¦ i have quite some of these Xiaomiās, all running perfect, also very accurate, all sending data to HA via BT Proxy, so i tried to put one in my fridge. Fridge is in a basement, in 2x2m storage room, while BT proxy esp32 is 3 meters away and behind door (of that 2x2 room), I didnāt get any data (even with opened room door). It started immediately when i opened the fridge door, though.
So, i guess iād have to put btproxy receiver right next to the fridgeā¦
Iāve found the range of my BT Proxies to be fairly short. I have quite a few spread around my house (not dedicated, just added to existing ESPHome projects) so I have pretty good coverage, but still have a few BT sensors that are spottier than Iād prefer.
Havenāt had any issues with any of the temp sensors getting picked up inside both a deep freeze and a fridge/freezer, but I also already happened to have BT Proxies quite close by (a meter or two) with no other obstructions.
There is no probe. Amazon.com: Inkbird Wireless Thermometer Humidity and Temperature monitor, IBS-TH2 Freezer Thermometer Bluetooth Temperature Sensor Smart, with APP for Android and iOS (Temperature and Humidity Sensor) : Appliances is the Amazon link to the device I have.
1 Like
@CO_4X4 I use the inkbird too in the freezer, works really well. An ESP32 is used as a bluetooth proxy, not even very close either. For the first battery replacement I used lithium ones, those last longer and work better in extreme cold.
1 Like
Just ended up going through the door seal for the freezer, all looks good now.
I really donāt understand why everyone always insists on using internal temp sensors to know when the fridge/freezer has a problem and then they go and stick battery powered esp projects inside of them or my absolute favorite is when they convince themselves that drilling a hole though it is a good idea!
why not use power metering and establish a ānormalā hourly/daily range and then obviously seeing no power or a dramatic increase or decrease in power would then trigger an alert that something is amiss and needs attention.
If the goal is to know when a problem occurs and can then be addressed rather than walking into a spoiled meat nightmare then it achieves that goal. That is just 1 of a few different ways and doesnāt involve drilling holes through your freezer as if that were ever a sane/rational idea.
1 Like
Thatās mostly what I do, I also have sensors inside from Wireless Tags but the power metering is my first indicator.