Extra temperature sensor / New weather station?

[pon...@gmail.com]

I've been using a rebadged Fined Offset WH1080 for a few years and it works well enough that I rarely think about it*. However, I'd like to add one more outdoor temperature sensor to my set up. Recording the data would be nice but isn't essential--not, by itself, worth buying a new weather station for.

Why: I just want to keep tabs on the temperature overnight in the chicken coop :-)

Currently my sensor unit is in the vegetable patch on one side of the house and the chicken coop is on the other, down the garden. The prospective new sensor location and the existing console are about 50m apart.

One low cost option might be putting a cheap LCD weather display in the kitchen, with an outside sensor in the chicken coop.

However, it appears that many of the low cost LCD weather displays that come with 1 or 2 outside sensors operate at the same wireless frequency (433MHz) as the WH1080 and I assume there'd be some risk of interference given a nominal range for the WH1080 of 100m (the land is on a slope and wi-fi doesn't reach from the house to the coop--whether that's significant I don't know).

How likely am I to have interference if I used one of these devices?

A comment (not a complaint): it's not that easy to match up things from the WeeWX hardware comparison page with products for sale online, on Amazon for example, given the extent of rebadging. It's fine if you want to compare some specific models of popular brands but, to give an example, not so easy to identify which units match certain criteria (having two or more outdoor sensors, UV recording etc). The manufacturers own web sites (Hideki e.g., even Fine Offset) are poor :-(

Happy to hear of any recommendations from anyone who upgraded from a WH1080 to add an extra sensor or two. (Longer term I'm keener to add a touch screen to my Pi and have individually replaceable sensors than to buy a high-end unit).

*This post occasioned in part by my changing the batteries in the console and the sensor unit yesterday, after about 10 and 5 months respectively. I forgot to note how long the station had been up for before doing that. An unlinked? web page with uptime statistics and an ability to display manually logged events (such as battery changes or power outages--had both yesterday, which is how I discovered batteries needed changing) would be nice for the slightly less organized. I normally leave post-it notes of battery changes on my desk but somehow (cough) they got tidied up some time ago and I missed a few signal dropouts recently because I didn't scroll all the way to the end of the display.

[Greg Troxel]

pon...@gmail.com writes:

> However, it appears that many of the low cost LCD weather displays that
> come with 1 or 2 outside sensors operate at the same wireless frequency
> (433MHz) as the WH1080 and I assume there'd be some risk of interference
> given a nominal range for the WH1080 of 100m (the land is on a slope and
> wi-fi doesn't reach from the house to the coop--whether that's significant
> I don't know).
>
> How likely am I to have interference if I used one of these devices?

I have been using rtl_433 to listen to sensors, and generally they send
a very short burst at some interval, usually somewhat under a minute.
So occasionally they will collide, and usually they won't, and missing
one observation probably isn't that important.

So if your real goal is to just monitor the chicken coop, I would think
about a very low end acurite temp/humid sensor/display. You could add a
rtl-sdr and rtl_433 to inject this into weewx for recording. Total
cost probably $50.

Another option is to get a Davis Vantage Pro 2 (perhaps Plus if you want
UV and solar radiation) and a second temp/humidity sensor. With the
computer interface, that's going to be around $1000.

[vince]

Sounds like your problem is network connectivity and geography more than anything else.

• You can build a small arduino wifi temperature sensor with a nodeMCU and a ds18b20 on a breadboard for under $15, but that doesn't help you if wifi doesn't reach.
  
• You can also buy a small inside/outside temperature+humidity Acurite wireless sensor for under $20.  I wouldn't worry too much about which radios they use and conflicts there.
• Or put the sensors on a pi and have your main weewx setup query that pi for the remote data over wifi (that's what I do at home).

FWIW, I upgraded my wifi 18+ months ago to a Ubiquiti AC Lite and that made a huge distance here.  The Ubiquiti gear has very powerful radios.  I'm sure it would reach 50m line of sight, but if it's over a hill it's hard to say.  There are lots of ways to do wireless repeaters etc but that ups the cost and complexity a lot.  The temperature sensor stuff is easy in comparison.

[pon...@gmail.com]

I just found this on eBay.

Any idea what I'd need to do to get the data with WeeWX?

I have a wi-fi extender in the kitchen (router is in my study at the other end of the house). The issue is less distance than height. The back garden is on a slope. I've experimented with putting a wireless access point in the sun room overlooking the garden but a connection was about 12 ft away and upslope from where I'd like and even that was with cable trailing into that room. I have power in the coop and could use an old pair of ethernet over power adapters (tested and works ok) but I think it's not worth the electricity for now (I use it to power an electric fence when we're away and a floodlight with motion sensor--anti-fox measures). If I ever add CCTV... :-)

[vince]

On Thursday, November 29, 2018 at 3:29:37 PM UTC-8, pon...@gmail.com wrote:

I just found this on eBay.

Any idea what I'd need to do to get the data with WeeWX?

There are lots of posts about people battling Acurite hardware.   If you pick a random piece of hardware, things get tougher to figure out.  Sometimes just buying previously-integrated hardware is worth the extra dollars/pounds/euros.

I have a wi-fi extender in the kitchen (router is in my study at the other end of the house). The issue is less distance than height.

It's a network thing.  If you had solid wifi between the physical locations, the options get easier.

[pon...@gmail.com]

Your $50 suggestion sounds good, however I'm not familiar with rtl_433 or rtl_sdr. I'll see what I can find but grateful for any pointers. Thanks.

[rich T]

Here is some information on rtl_433:

https://github.com/merbanan/rtl_433

And information on a SDR:

https://www.amazon.com/NooElec-NESDR-SMArTee-Bundle-R820T2-Based/dp/B079C4S2BT/ref=sr_1_1_sspa?ie=UTF8&qid=1543792627&sr=8-1-spons&keywords=rtlsdr+v3&psc=1

[pon...@gmail.com]

OK. Makes sense. Actually, I can have wired connectivity in the coop using a couple of old ethernet over power adapters (tested and work oks and could be used to add wi-fi) but I thought this would be a bit over the top to just get a temperature reading. I am not familiar with Acurite sensors. Are you saying that there are ones I can buy that will, in principle, just work? Thanks.

[Greg Troxel]

pon...@gmail.com writes:

> OK. Makes sense. Actually, I can have wired connectivity in the coop using
> a couple of old ethernet over power adapters (tested and work oks and could
> be used to add wi-fi) but I thought this would be a bit over the top to
> just get a temperature reading. I am not familiar with Acurite sensors. Are

I don't see why you say that. If you can put in a POE access point, and
have it be reliable, that seems like a huge win, and could be worth it.

> you saying that there are ones I can buy that will, in principle, just
> work? Thanks.

Yes, these sensors are inexpensive and reasonably reliable. They take 2
AA batteries and transmit temp/humid on 433 MHz, which rtl_433 with an
rtl-sdl can receive. Picking the manufacturer site rather than a
shopping link:

https://www.acurite.com/temperature-and-humidity-sensor-06002rm-592txr.html

There is also one that does temp/humid and lightning, but it needs 4
batteries, costs more, is bigger, and the rtl_433 support for it is I
would say only 90%.

https://www.acurite.com/lightning-detector-with-temperature-and-humidity.html

[pon...@gmail.com]

Thanks for the link. It's not accessible in the EU; will check with a VPN later. 

Would you recommend something different if I had wi-fi or Ethernet in place?