I Just Got A TOTALLY Local, ie, Dumb, Refrigerator Wireless Thermometer

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I'm doing stuff based on lessons learned during a recent two day power outage.

I found it useful to monitor the refrigerator's temps so the food wouldn't spoil. I could start the little generator before going to bed to get it cool overnight (that was a lesson learned). Better than the one night I emptied the fridge to put all the food outside in the barely sub-freezing temperatures.

Anyway, any attempt to use Hubitat failed because, for whatever reason, the Hue motion sensor in the fridge, along with a bunch of other Zigbee devices, dropped off the mesh. Plus, the WiFi router as well as a laptop, for me, have to be running as well.

I put a dumb wireless thermometer that I had laying around in the freezer and it worked great. Could see what the temperature was at a glance. No computer, network, mesh, etc, necessary.

I just bought a purpose-made one from LaCrosse. I think it has a lot of potential. It does both freezer and fridge sides, hi/lo temps and alarms (with sound), and the display is quite large and uncluttered. I can see it from pretty far away.

I also like the fact that it can be set to display whole numbers, instead of merely decimals.

As far as accuracy, I actually think it's settled in somewhat overnight. It had been reading higher than the three Hue motions I put in the freezer to compare with. It's now closer, and is reading what Frigidaire recommends as temperature settings, so, I'm going to keep it.

Best of all, it matches my new black Frigidaire side-by-side.

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If you want to go through the trouble, this is almost certainly readable with a USB SDR dongle and 'rtl-433' software running on a computer, which can either output to MQTT or POST JSON. Either of those is easily ingested into Hubitat.

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That's all Greek to me, lol.

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Yes, that is what happends when you put low powered wireless devices inside a metal box. There are a few zwave devices that support external temp probes that can read the temp inside while keeping the zwave radio outside and thus on the mesh. but yeah… that works too…

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There was something about the hub backup battery failing, leading to the mesh being down overnight. Zigbee devices affected were the majority, not just the one in the metal box. When on generator, if I would take a battery powered sensor that fell off closer to the hub, it would start communicating again. If I then put it back in its original position, it would drop off again. No problems after utility power came back.

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The older I get, the more I like simplicity. If a simple thermometer with a display on the outside of the fridge gives you all the info you need, go with it. Sometimes we twist ourselves into knots trying to solve a problem that just isn't there, or that we invented in our own heads. So you won't know that the fridge went kaput when halfway around the world on a trip... What would you do about it but worry from there, anyway? Better to enjoy the trip, in the moment.

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Another complication of modern fridges is that, without power, the ice in the ice maker bin will melt and leak all over the place. I pre-emptively emptied it into the sink. Never mind the water line that could break. But that's what leak detection sensors are for. :slight_smile:

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Simce you are already in the Ecowitt cult, something like this could work too, give you both readings in the Ecowitt app and Hubitat, but still has the visual display if everything fails. WN31_EP(WH31_EP) with SHT35 Probe – Ecowitt

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You'd have to snake that wire through the door gasket. Or, drill a hole. I could have used that extra sensor I have, and put it in the freezer. I'm pretty sure it would have the signal strength. Then i could have moved the little display closer so that i could read it. I guess.

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A consideration is that the battery backup up on the little display doesn't last long and the screen blanks out after a minute or so to conserve battery. That reminds me, maybe i should change them out. :slight_smile:

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True, but if you put it in front of the gasket, I doubt the cold loss would be of any significance, if any at all, I doubt behind it would even be noticeable. I've been debating replacing the Zooz temp sensor in my safe with one of the Ecowitt sensors. I'll let you know if it works, the only drawback would be you have to open the fridge to read it if you lose at your network.

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Yolink - Works great in a metal box (both my Fridge and 1/8" plate mailbox) and can tie into HE for rules, alerts, etc. - Display is visible in the Fridge, and the T/H sensor can even do trending in their cloud - Requires an internet connection for their API and HE interface, but they are promising a new LoRa hub with local matter support (any day now).

Obviously YMMV, but I've been very happy with YoLink, for very long range, and "inside metal boxes" sorts of applications.

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I’ve heard that before…

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A moment of silence folks, @marktheknife has been hurt before.
:wink:

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Let me just say that the Hue indoor motion sensor inside the side by side refrigerator has been solid as as rock, UNTIL there was a recent power outage, plus subsequent restoration with portable generator, and most of the Zigbees dropped off. It might actually have been of some real use. But isn't that always the case. :slight_smile:

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I use the Ambient version of this. And it works well. On the Ecowitt side I use a couple of the soil moisture sensors with their info displayed on a dashboard.

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Seems that's a crumbly rock. Makes for a lousy foundation. Not always the case. Go Ecowitt.

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With the large numbers, I can see the display easily from my morning perch in the kitchen.

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