meteohub.de

Hej all,

I am not new to weahter equipment,but I am new to the RFXCOM and it capabilities. I have a nice sensorscreen and a very precise Tinytag Ultra plus datalogger (ofr min, max and average temp with a very high precision).
I have had experince with Davis WM II, but now want to go wireless and cover 200 m distance (through a fewwalls). What are the possibilites to reach this distance with the RFXCOm and Oregon Scientific sensors like their thermo hygrometer, UV sensor, Rain gauge and windspeed/direction meter. Or witj the sensors used with the WMR 100 (partially the same). I read from a Norweagian member the occasional signal of sensors 500 m away.
What is important? The transmitter (OS sensors) or the receiver? WIl RFXCOM do a better jon than the base unit of a WMR 200 or WMR-200?

If I attach it to the Meteohub, will meteohub detect the RFXCOM and immediately log data from sensors, or is there some work to do (install things etc) yourself. Does RFXCOM get power via the USB interface of the Meteohub, does it work on batteries or is there a connector for standard 220V power (with adapter)??

Thansk in advance for answers!

J.S. wrote: I have had experince with Davis WM II, but now want to go wireless and cover 200 m distance (through a fewwalls).

Probably obvious but the effect of the walls will depend on what they are made of. Platerboard? Brick? Stone? Reinforced concrete?

I read from a Norweagian member the occasional signal of sensors 500 m away.

I'm not in Norway, but if you mean a Meteohub Forum member I think that may have been me!
My RFXCOM receiver (and Meteohub) are in my loft, and the antenna is in the roofspace near the very apex of our roof (that just happens to be a convenient arrangement here). I occasionally pick up stray signals from someone with a WMR928 500m away. His station is on a hill and there is direct uninterrupted line of sight between his equipment and my antenna. I live in a very rural area so there ought to be relatively little general electrical noise in the area.

N.B.
a) I have the earlier RFXCOM receiver with a 'ground plane' antenna. The newer model has, I understand, a telescopic antenna. I have no experience of that.

b) My impression is that WMR928 sensors may have slightly better transmitters than the WMR200 equivalents. The WMR928 wind, rain & outdoor temp/hum transmitters being separate to the actual WMR928 wind, rain & outdoor temp/hum sensors, on long leads, means that they are certainly easier to place in advantageous positions for the best signal path.

What is important? The transmitter (OS sensors) or the receiver? WIl RFXCOM do a better jon than the base unit of a WMR 200 or WMR-200?

My experience is that the RFXCOM receiver is far more sensitive than the WMR200 console.

The WMR200 manual mentions an effective range of 100m in an 'open area'.
My personal experience with the WMR200 console is that it if any walls are involved you would be doing well to get reception at even 50m let alone 200m. If you search on the Weather-Watch.com Forum you'll find comments from others on WMR200 reception too.
I'm not radio expert but I don't think the WMR200 is peculiar in this - I get the impression that 100m in ideal conditions is pretty much the norm for the protocol and bandwidth that the WMR200 is designed for.

The RFXCOM receiver is an excellent piece of kit and might do the job for you, but it is impossible to be certain. It may be that even with that you need to consider a repeater too.

If I attach it to the Meteohub, will meteohub detect the RFXCOM and immediately log data from sensors, or is there some work to do (install things etc) yourself.

You plug the RFXCOM in to the USB port on the NSLU2. You tell Meteohub that it is connected to an RFXCOM. You tell Meteohub which identifiers you want to attach to the sensor readings it is receives from RFXCOM. I found the instructions in the Meteohub manual to be very clear.

Does RFXCOM get power via the USB interface of the Meteohub

Yes.

I hope that helps.

Hej,

First of all thank you for your help, because it sure helps!

You are the supposed Norwegian I was talking about, don't know why I thought that, sorry. I already realised I made that mistake this night after I wrote my previous questions...

I live in the Netherlands but my stations are placed in rural areas as I want to compare with KNMi data, which is impossible to do in a garden or other areas influenced by buildings or trees. I won't be able to put. I will have to pass some brick walls, that is sure.

I thought of this option: there are repeaters available for the OS 928/968 series. So I by a RFXCOm with a meteohub. Then, I buy humidity and temperature sensors for the 928/968 series which I place well into the country 200 m from the farm. One repeater at 80 m, another on at 80 m so it only has to pass 40 m to the RFX com. I will place a UV sensor much closer to the farm, as it only needs to get full sunlight. Hope this works. I porbably will change my mind a couple of times as I will find more info on this, but this is what I think
right now.

Is it possible to attach the meteohub server (NSLU) to an UPS. Read that this is not possible. So it works on batteries and not 220 V (with an adapter)? If so, I cannot understand what the problem is but will read the handbook.

I think the meteohub+NSLU is especially a very good substitute for a datalogger for people with an OS 928/968 and WMR-100 station.

BTW, what is your experience with the precision of the ORegon sensors. Did you ever compare??

Does anybodu now if the repeated signal by the OS repeaters is accepted by the RFXCOm (should be, but who knows)?

Are there senders+receivers form RFXCOm which could be used as repeaters??

Thanks in advance for the answers!

Best regards,

Jorge

J.S. wrote:I buy humidity and temperature sensors for the 928/968 series

The 928 comes with its own main 'outdoor' temp/hum (and wind, and rain , and indoor temp/hum/baro). Additional temp/hum sensors can be purchased. The additonal sensors don't have the advantage of solar panels and long leads - but you probably knew that.

Then, I buy humidity and temperature sensors for the 928/968 series which I place well into the country 200 m from the farm. One repeater at 80 m, another on at 80 m so it only has to pass 40 m to the RFX com.

Unless you can get a really good deal on buying all the equipment at once, my inclination would be to buy the WMR928/968, the NSLU2, Meteohub and the RFXCOM and see what range that managed in your situation, then add one or more repeaters if they proved necessary.

Is it possible to attach the meteohub server (NSLU) to an UPS. Read that this is not possible. So it works on batteries and not 220 V (with an adapter)? If so, I cannot understand what the problem is but will read the handbook.

The NSLU2 is mains powered.

My NSLU2/Meteohub is attached to a UPS.
I think what they may mean is that there isn't an interface to allow the UPS to tell the NSLU2 that the power has failed and that it is about to shutdown.
I have my UPS set to run as long as possible. At around 10W on a 400VA UPS that ought to be a long time (sadly the only time it has been really necesary the UPS shutdown after only an hour or so, I almost wonder if the load was so low that the UPS though there was nothing there!).
The shutdown did not cause any data problem.

I think the meteohub+NSLU is especially a very good substitute for a datalogger for people with an OS 928/968 and WMR-100 station.

Agreed. :)

BTW, what is your experience with the precision of the ORegon sensors. Did you ever compare??

I've no reasons to doubt the specs in the manual.
This is not 'professional' equipment, but it seems fine for the uses I put it to.
For good temp/hum values I strongly suggest some sort of radiation shield.
You might also be interested to read the link I quote in my PS. below.

Does anybodu now if the repeated signal by the OS repeaters is accepted by the RFXCOm (should be, but who knows)?

Are there senders+receivers form RFXCOm which could be used as repeaters??

Maybe it would be a good idea to ask RFXCOM support?

Any answer you receive might be of interest to others too.

PS. In a reply I recently wrote on Weather-Watch.com I compared the WMR200 & WMR928 and commented a little on the equipment. There might be aspects of that reply that are of interest to you:

http://www.weather-watch.com/smf/index. ... #msg264873