Solution for wireless monitoring of freezer and/or refrigerator temps

[ecborgoyn]

Some food the thought and discussion:

Does anyone have a good inexpensive solution for wireless-ly monitoring the temperature of freezers and refrigerators? I mean a system connected solution (e.g. Elk M1). Wireless connectivity to avoid holes and wires into the unit. I realize that freezers/refrigerators might not be RF-friendly. So I'd accept a dedicated receiver device near the monitored freez/frig and a very short RF link to a battery powered temp transponder inside the unit. The receiver device would be system 12VDC powered and system connected.

In some brief Google-ing I found some commercial devices (i.e. $$$$). I also found a couple of wireless monitoring devices that provide temp display and alarming external to the freez/frig unit. But these were standalone devices and could be interfaced to a 'system'. But these products do give me hope that a short-haul RF link can work from inside of a freez/refrig unit.

Any thoughts?

 

[apostolakisl]

Some food the thought and discussion:

Does anyone have a good inexpensive solution for wireless-ly monitoring the temperature of freezers and refrigerators? I mean a system connected solution (e.g. Elk M1). Wireless connectivity to avoid holes and wires into the unit. I realize that freezers/refrigerators might not be RF-friendly. So I'd accept a dedicated receiver device near the monitored freez/frig and a very short RF link to a battery powered temp transponder inside the unit. The receiver device would be system 12VDC powered and system connected.

In some brief Google-ing I found some commercial devices (i.e. $$$$). I also found a couple of wireless monitoring devices that provide temp display and alarming external to the freez/frig unit. But these were standalone devices and could be interfaced to a 'system'. But these products do give me hope that a short-haul RF link can work from inside of a freez/refrig unit.

Any thoughts?

This info may help, but isn't exactly what you need. I have a lacrosse technology wireless temp/humidity unit. It is dirt cheap and I have it in my kegerator and wine room. The rf signal has no trouble getting out of othe fridge and wine room to the sensing units, one of which is at least 50 feet away.

I think this model might work for you. http://www.lacrossetechnology.com/2810/index.php It states it has weather alarms which I would speculate might do the trick for you as far as maybe sending an email or something.

 

[ecborgoyn]

Good thought. I didn't think about wireless outdoor thermometers... I'd might be able to integrate the data via a serial link. I'll do some reading.

Any other ideas out there?

 

[Del91574]

Winland. We use their devices for freezer/cooler monitoring and humidity as well.

 

[ecborgoyn]

Winland looks OK for the application. But I was mainly looking for a wireless solution where the entire transducer and transmitter could be inside the freezer/refrig. Winland allows the sensor inside, but the transmitter outside. The wireless outdoor thermometer still looks good. I also like the analog nature of the outdoor thermometer over the Winland solution. I really don't want to make holes in the freezer wall and/or run cables for sensors.

 

[signal15]

There's a device that has been talked about on here before that is kind of a universal wireless sensor data gathering device that plugs into your network. It supports sensors from most of the major "el cheapo" thermometer companies, and I think it also supports Zwave/X10/etc.

I can't remember the name of it though.

 

[Del91574]

1 wire.

 

[apostolakisl]

1 wire.

That is probably what he was thinking of.

However, 1-wire by itself has a problem. . . it is the wire. I am not aware of any battery operated devices that take that wired 1-wire signal and put it out on any sort of wireless network. Perhaps one exists?

The super cheap lacrosse technology devices I have work incredibly well, they just don't easily get polled by a computer. The device I have for like $30 has a com port communicator on the receiver. If you knew how to write the software you could certainly use a pc to query it and then post that info to any other network device.

 

[Del91574]

Innovonics can also be used, but it seems like the OP wants to go the cheap route and possibly brew their own solution.

 

[gatchel]

Most wireless devices don't have a transmitter all-in-one becuase your refrigerator is basically a big metal box, not good for passing wireless signals at any range. The windland units are reliable and well built. I have installed several of their products with success.

 

[Del91574]

If no-drill is the spec, then a winland probe or others via the cable through the magnetic bellows/gasket would be the way I'd go.

 

[RAM]

If no-drill is the spec, then a winland probe or others via the cable through the magnetic bellows/gasket would be the way I'd go.

I did this years ago with a 1-wire probe going into my freezer. I cut the gasket to accomodate the cable for the 1-wire sensor. The only problem I had was the was a tiny air leak where the cable passed through the gasket. I finally solved that problem by putting some silicone sealer on the gasket and closing it on the cable so I'd get a form fitted seal around the cable. But, first I sprayed the cable with silicone spray so the silicone sealer wouldn't stick to it, only the gasket. Sealed it up tight enough that I don't get frost inside the freezer from outside air leaking in.

 

[apostolakisl]

Just to test if my RF lacrosse technology deal was working in my keg fridge for some odd ball reason, I put it in my regular fridge. It works fine. There is no doubt that this fridge is full metal construction on all sides. It is this one http://www.number1direct.com/product1/Thermador-T33IR70NSP/Thermador-T33IR70NSP.html?trackcode=AmazonAds

I would be very careful doing anything to the gasket if it is a higher end unit. Units like mine, subzero, and so on maintain a relative vacuum inside the unit. If you damage the seal you will be in for trouble.

 

[ecborgoyn]

I'm looking for a lower cost (I don't like the term 'cheap'.... ). Spending $50 and writing some communications s/w would be great with me. I don't need a $250 dollar solution to monitor a few $100's of food. I also don't need a 'canned' solution that can directly interface with my M1G. A serial port connection is fine, as long as the protocol is specified, or easily reverse engineered.

Looking at the Lacrosse products. The <$20 transponders look attractive. What is the minimum 'base station' that incorporates a serial comm. port? I can do the polling from a host computer if necessary.

 

[apostolakisl]

I'm looking for a lower cost (I don't like the term 'cheap'.... ). Spending $50 and writing some communications s/w would be great with me. I don't need a $250 dollar solution to monitor a few $100's of food. I also don't need a 'canned' solution that can directly interface with my M1G. A serial port connection is fine, as long as the protocol is specified, or easily reverse engineered.

Looking at the Lacrosse products. The <$20 transponders look attractive. What is the minimum 'base station' that incorporates a serial comm. port? I can do the polling from a host computer if necessary.

Unfortunately the base station I have can not be polled. To the best of my knowledge no one has hacked the software so you can only use the software they provide which requires manual intervention. That is the ws-8610 unit.

They have much more advanced base stations than mine. The software for them is much nicer, but I have never played with it to know if it is possible to setup scripts on it.

If you google "hack lacrosse weather station" you will see that people have done hardware hacks on them, but you would need to be a serious tech geek to be able to do that.

Incidentally, I did check the base station in the master bath this am to see if it was picking up the transmitter in the kitchen fridge, and it is. The master bath is completely on the opposite side of the house. So the RF signal on these is quite robust.