Need Freezer sensor

I have the Iris v2 motion sensors, which also report temperature, in my two freezers and refrigerators. I use the native notification app to notify me when the temperature is above a certain level. Very easy to set up.

I was worried that the radio signal wouldn't penetrate through the refrigerator/freezer walls, but it does. I was also concerned about battery life, but after one year the batteries are still working.

You should be able to find Iris v2 motion sensors on ebay. They are great sensors.

I've also been using Iris V2 contact sensors in refrigerator and freezer compartments on ST and HE; batteries do usually last for a couple of years (though the battery levels reported are best ignored). I suspect that the bottoms of most refrigerated compartments are just plastic and insulation with just some metal bracing; probably why my sensors wound up routing through repeaters in the basement.

Ordered 4 v1 sensors on eBay for $20 shipped. Inspired to put in my refrigerator and freezer for fun. Thnx for the inspiration. :slight_smile:

Thanks for all the ideas, I’ll look into each and see which seems the best for my situation.

From what I saw on the web site, it looks like these are Z-Wave. No thanks.

I believe @iharyadi ‘s rock solid sensors can accept an external probe. Very affordable and reliable. Zigbee and functions as a repeater (Xiaomi compatible too).

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@SmartHomePrimer thanks for mentioning my module. I really appreciate it.

Let me get right into what I think my sensor can do in the context of monitoring freezer.

The sensor that I have been making here has Analog Input that you can connect to an Thermocouple probe through a module like below. BTW, they can be had much cheaper if you do not mind Ebay route. Below is just an example.

https://www.amazon.com/Adafruit-Analog-Output-Thermocouple-Amplifier/dp/B00XW2N6E0/ref=sr_1_8?dchild=1&keywords=analog+output+thermocouples&qid=1590617958&sr=8-8

You will also need a probe like below.

https://www.amazon.com/s?k=k+type+thermocouple&crid=2PNFAZNMKNMV1&sprefix=k+type%2Caps%2C221&ref=nb_sb_ss_i_1_6

Using the probe (some has long cable), you will have the electronics outside the freezer. I have written DTH to use it. There will be no coding on this path.

However, that was the only option about a year or so ago. Today, my module can accommodate serial port connection. You can go with Arduino route to read temperature sensors. The module will act as ThingShiled. With this route, you can use probe like below.

https://www.amazon.com/CenryKay-DS18B20-temperatura-impermeables-3-3/dp/B07H3P8LRT/ref=sr_1_4?dchild=1&keywords=ds18b20&qid=1590618359&sr=8-4

Which again can be had in Ebay for a lot less. An Arduino uno clone is also be gotten for a lot less. The only down side on this route, you may need to write a bit of code in Arduino side. But, you will be able to do a lot more. The above sensor only take one of your Arduino pin. There are a couple pins needed for Serial ports. You still have more than a handful of pins on the Arduino for other stuff. Perhaps adding contact (reed switch) to monitor the door.

One aspect of the module is the battery backup. Some member here use it to detect power outage. Perhaps, this is important for freezer. You may not have to wait until your freezer temperature rising to know that something is about to go wrong by monitoring the power line. The module is powered by DC and has battery backup. If you add an LIPO or LI-on battery and the hub has battery backup, you can add circuit to monitor the power to the DC or monitor the battery report. Later is slower but no code/hack is needed. You can act faster if you have something valuable there.

As @SmartHomePrimer say you will get a Zigbee Repeater with extended Radio (additional amplifier),

Thanks. Please give it a consideration. I am here as community member will help you any path you take.

br
Iman

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Has any used Iris V3 contact sensors (IL06) as temp probes in freezer/fridge?

Soo.. let me verify

DWS800 is V1
3320-L is V2
iL06-1 is V3

Correct?

That makes each for 10 on ebay without magnet's
V1 $28.99
V2 $49.90
V3 $42.90

Are V2 that much better? I really only need 4 temp sensors for fridge freezer... But I'm sure I'll find a place to use extra ones...

I use the Sonoff TH16 with a SI7021 temp/humidity sensor, why I like this is the sensor is the only part in the freezer. I have flashed this with tasmota and I am using @markus universal drivers. This driver also has presence which I also use to notify me if this does not report in. I also use notifications if the temperature rises above -5 degrees C. Currently it has been in the freezer for about 3 months and the freezer temp is -22.5 degrees C.

All I have done is stick the Sonoff TH16 on the wall just behind the freezer and run the sensor wire (it is a bit short) into the freezer through the magnetic seal. This runs off mains power so no battery to worry about.

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I just want to add some information so that we are all be better educated as a buyer of temperature sensor

The architecture that @greglsh mentioned used dedicated temperature (in this case come with humidity) sensor. These kind of sensors is built to be much better than temperature sensor that come in the MCU.

Most suggested devices that you put in Freezer to measure the temperature is using MCU internal temperature sensor. The makers, who used these sensors, in turn, advertise as one of the feature is that it is a temperature sensor. As a buyer, I think we ought to know about this fact to make our decision.

If you search around google, you will find this comments about internal MCU temperature sensor. I do not undermine a specific Mfg because we just looked the internal temperature specification only. This is a great Zigbee Manufacture MCU with a great product. Here is one of the employee opinion on the MCU temperature sensor. I would not bog down about the 0.1% accuracy. But, there are complexity on handling the error with the reference, adc performance and etc.

Sensor like SI7021 is built from ground up to be temperature sensor.

As a buyer, I think we should look at what our goal for the monitoring. If your tolerance is so high that you would say "as long as it is cold", then any solution is good. But, if you start needing to make sure that I want my meat or ice cream from Japan is at -5 degree F, this is an indication that you want a full featured temperature sensor.

I hope it help.

Thanks
Iman

I ended up going with Ecowitt seeing as their sensors are dedicated. I know that they are not Zigbee/Zwave but there is a driver for local access to the sensor data.

That’s correct. The reason why the v1 sensors are usually the cheapest is because they use a proprietary zigbee profile that was only intended to work with Iris.

They will work with hubitat (thanks to @mike.maxwell) but personally I would always choose the standard ZHA 1.2-based v2 and v3 devices.

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So the v3 don't use standard ZHA 1.2 ?

Oops sorry I meant v2 and v3 use the standard ZHA profile, corrected my last post. Thanks.

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Okay I was confused, lol thanks.

Is there an reason the v2 is better than v3 though?

Not that I know of, they should be pretty similar sensors, I believe. I know the iris v3 motion sensors can also report humidity, although I’m not sure about the contact sensors.

If I needed more contact sensors, I would probably go for whichever is cheaper between v2 and v3.

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For the contacts, I personally would go with the V3 before the V2. They both work well, I just prefer the look and feel of the V3 units. There were early complaints of the V2 sensors having fragile battery contacts, but I have not experienced that problem. I currently have all three iterations of the Iris contacts connected to Hubitat and have never needed to reconnect any of the V2/V3 sensors. I did have a pair of instances where my V1 sensors all went offline. The V1s do not rejoin properly and need to be added back as new.

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Going on threads showing hacks of other contact sensors such as:

[Updated with a warning] Hack a Samsung SmartThings Multi Sensor V5

I put together the following components in order to get a notification of when my chest freezer has exceeded 15F which is far above the setting range I see of roughly -5F to +5F.

Xfinity XHS2-UE contact & temp sensor (selected for price and battery life from Ebay) Auto paired as a Generic Zigbee Moisture Sensor, had to force it to Generic Zigbee Contact Sensor

Senasys 2570L430-2204 - Opens @ 15F Closes @ 5F

More switch format and temp setpoint options:
http://senasys.com/product-category/epoxy-sealed-temperature-switches/three-quarter-inch-thermostat-switch/2570-open-on-rise

Their sensors are rock solid reliable and affordable, their shipping often costs more!

The soldering job was tricky and not pretty but good enough. I just used the long wires that came on the Senasys model I ordered. Should have spliced in thinner wires but this worked out with care taken and I will glue/seal with some E6000 from the exterior for good measure even tho the fit was tight.

First pic is the XHS2-UE which will hang on the adjacent wall providing ambient temp info (puposely did not want to put it and its' battery in the freezer). Second pic is the Senasys temp switch on the edge of the freezer. It is just suspended in the freezer by the wires draped over the edge (wires spread so as not to cause a large gap in the lid seal).

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In my opinion, this is another example of a good solution. Thanks for the idea using thermostat. In the case where I do not need granular temperature reading. It require only one digital io pin.