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Does this cheap temp sensor work?

Posted: Thursday 26 January 2017 10:50
by stuiow
Hi all,
Looking for a cheap sensor for my fridge and freezer.

Anyone any input on this device? Does it work with RFXTRX433?

http://www.ebay.co.uk/itm/311504966753? ... EBIDX%3AIT

Thanks!
Stuart

Re: Does this cheap temp sensor work?

Posted: Saturday 28 January 2017 13:03
by SweetPants
That is uses 433Mhz does not automatically means it's supported. Have you checked the supported device list ? http://www.rfxcom.com/WebRoot/StoreNL2/ ... _Guide.pdf

Re: Does this cheap temp sensor work?

Posted: Saturday 28 January 2017 14:56
by Jem101
A word of caution, some time ago, I bought two cheap temperature sensors from eBay which look for all the world like the one shown in your link. They seem to work OK in Domoticz and appear as a FineOffset/Viking device. But the reported temperature swings wildly between (and I'm not making this up) +85 degrees C and -145 degrees C which I were living on Mercury might be reasonable but it's a bit much even for London.

As I only paid about £5 for the pair, I'm not too bothered about it, every time there is a firmware upgrade for the RFXCom, I dig one of them out, put some fresh batteries in it and try it again, but so far no luck.

Of course it might be a different model inside but it does look suspiciously like the ones I have.

Re: Does this cheap temp sensor work?

Posted: Saturday 28 January 2017 21:01
by sion
I just got one of these to try:
http://m.ebay.co.uk/itm/Extra-Sensor-fo ... Ciid%253A1

Only £7.99, but it's currently 66 degrees c in here ;)

The temp has stayed stable only increasing or decreeing by a few degrees, so I may just need to adjust the offset in domoticz. Just need to get a real thermometer to set it to.

Would be interesting to know if you try the one in the post to see if it works well though. It's a good price if it does.

Re: Does this cheap temp sensor work?

Posted: Saturday 28 January 2017 23:31
by StanHD
sion wrote:I just got one of these to try:
http://m.ebay.co.uk/itm/Extra-Sensor-fo ... Ciid%253A1

Only £7.99, but it's currently 66 degrees c in here ;)

The temp has stayed stable only increasing or decreeing by a few degrees, so I may just need to adjust the offset in domoticz. Just need to get a real thermometer to set it to.

Would be interesting to know if you try the one in the post to see if it works well though. It's a good price if it does.
I have used 5 of these for 2+ years with an offset of -40 degrees. No problems so far :)

Re: Does this cheap temp sensor work?

Posted: Saturday 28 January 2017 23:36
by stuiow
I see Lidl here in the UK have temperature stations that are also posted in the bargains forum.
I may opt for a couple of those. Though worrying an update is received every 30seconds.
Might keep the rfxtrx busy.

Sent from my SM-G925F using Tapatalk

Re: Does this cheap temp sensor work?

Posted: Sunday 29 January 2017 0:27
by sion
StanHD wrote:
sion wrote:I just got one of these to try:
http://m.ebay.co.uk/itm/Extra-Sensor-fo ... Ciid%253A1

Only £7.99, but it's currently 66 degrees c in here ;)

The temp has stayed stable only increasing or decreeing by a few degrees, so I may just need to adjust the offset in domoticz. Just need to get a real thermometer to set it to.

Would be interesting to know if you try the one in the post to see if it works well though. It's a good price if it does.
I have used 5 of these for 2+ years with an offset of -40 degrees. No problems so far :)
Excellent.
-40 offset sounds about right to what mine is reading.

Re: Does this cheap temp sensor work?

Posted: Sunday 29 January 2017 18:38
by sion
StanHD wrote:
sion wrote:I just got one of these to try:
http://m.ebay.co.uk/itm/Extra-Sensor-fo ... Ciid%253A1

Only £7.99, but it's currently 66 degrees c in here ;)

The temp has stayed stable only increasing or decreeing by a few degrees, so I may just need to adjust the offset in domoticz. Just need to get a real thermometer to set it to.

Would be interesting to know if you try the one in the post to see if it works well though. It's a good price if it does.
I have used 5 of these for 2+ years with an offset of -40 degrees. No problems so far :)
I have just noticed the one of these I have is updating and writing to the log approx once a min. Just wondering if you have 5 of these going, has it caused you any problems with rf interference? Or sd card ware?

Re: Does this cheap temp sensor work?

Posted: Sunday 29 January 2017 18:48
by StanHD
Every once in a while, 2 will "collide". This lasts @ 12 hours or less, then all good for another 6-8 months or more. I use an SSD on an Intel NUC so not really worried about the writes.

Re: Does this cheap temp sensor work?

Posted: Thursday 07 June 2018 22:41
by SDISDI
Hi. I bought one of the sensors discussed above to monitor temperature (and alarm) for a chest freezer. Worked fine, even with the low temperatures and in the metal box!

http://m.ebay.co.uk/itm/Extra-Sensor-fo ... 1788376051

Issue was, when I enable the protocol FineOffset/Viking on RFXCOM, as per the manual, it impedes a HomeEasy PIR sensor I use. The PIR is more important, so I have abandoned the sensor for now.

Can anyone tell me if the item below uses the plain Imagintronix protocol? (which is fine with the HomeEasy kit I have)

https://www.ebay.co.uk/itm/Wireless-The ... 1397773764

Thanks.