Using a single remote sensor with two Watson W8681 displays

[MikeS]

I wonder if anyone can advise me, please?

I'm in a situation where my Watson W8681 has been commandeered for use in the kitchen. My webserver is 2 floors away and I would like to run the web-facing option in Cumulus using a second display unit, permanently plugged via USB.

Does anyone know if it is possible to operate TWO receiver units from a single sensor head, or is there some data handshaking which will only serve to confuse?

Cheers!

[steve]

Yes, you can operate two receivers from one transmitter. You need to make sure that the second receiver is compatible with your transmitter, as there are a number of different versions.

[MikeS]

Many thanks for such a speedy reply, Steve!

All I need to do now is determine if the two available from Maplin are from the same stable. They are advertised as a "Black [or silver] USB Wireless Touchscreen Weather Forecaster" but look as if they are just another badged Fine Offset WH1081 which is what I believe the Watson W8681 is.

Getting closer to a result!

Cheers!

[MikeS]

Just stumbled across the excellent wiki and discovered the list of compatible equipments.
http://wiki.sandaysoft.com/a/Supported_Devices

[steve]

But note that not all of the Fine Offset stations are compatible with each other (which was the point I was trying to make). Even allowing for the fact that some use 868 Mhz and some 433 Mhz, and some have solar sensors and some do not, there are apparently other internal differences in the way they transmit their data. Even if two stations look very similar, their transmitters may not be compatible with each other. These differences don't affect Cumulus, but are important for what you want to do.

That's my understanding, at least. Alan (Allycat) is the resident expert on FO hardware and knows more about this than I do. I'll move the thread to make it more likely that he sees it.

[MikeS]

Thanks for your wise counsel Steve and for moving this to a more visible part of the forum.

The two units I'm looking at are the Maplin N96FY/N96GY units, but as you say my compatability requirements relate to the Tx/Rx function, for only one will ever be connected to Cumulus. Even though they both appear to offer identical functions [and no more] to the W8681, it is no guarantee, unless perhaps Alan picks up on this and can advise.

Cheers!

[sfws]

Alan (allycat) knows the technical stuff and I do not...
But as I understand it, based on reading his excellent contributions previously, some transmitters use a different protocol to represent the '0' and '1' (or whatever needs to be represented) states to other transmitters, so your receiver needs to match the protocol.

Maplin N96FY/N96GY units

I do know that Maplin has used the same product number for various different incarnations of Fine Offset designs to add to the confusion, but maybe they just sell whatever version they get in a particular batch from Fine Offset, and if for example two colours of the case are available then those get different product numbers (such as F and G in examples you quote).

[AllyCat]

Hi,

Thanks Steve, yes I've found this thread but I don't have any "inside knowledge", nor any direct experience with the "Watsons", so cannot give any definitive answers. However, Steve is absolutely correct that, in principle, one transmitter can "broadcast" to two (or more) Consoles and the first factor of "compatibility" to ascertain is the same radio frequency (generally, 434 MHz in Australia, 868 MHz in Europe, either in UK, and 915 MHz in North America).

The frequency is usually written in the specification and/or on the battery cover of the Console and maybe the transmitter. The "Clas Ohlson" badged versions are always 868 MHz and in my experience all Maplin's (and Signatrol's) are 434 MHz, but somebody did recently post on this forum that Maplin had changed to 868 MHz (which I consider unliklely). Other "brands" such as Walters & Stanton and those on Amazon seem to have been offered with one or the other frequency.

Then, there is the "Wireless Protocol", i.e. what (and how the) data is transmitted. I believe the protocols are always different for 434 and 868 MHz and the "transmitters" can use at least 3 different formats: "normal", or without wind direction, or with Solar Data (Lux + UV), which the corresponding Console then "expects" to receive. Generally, stations with the same model number will be compatible, but with the exception that Maplin (or strictly FO) changed their protocol about 2 years ago without changing their model numbers. However, AFAIK the "black" and "silver/cream" Maplin stations are completely compatible, but why anybody would want a "black" Solar Screen is beyond me (except when it's much cheaper ).

Finally, a few of the above brands do sell "spare parts" (Maplin usually the most competitively), but I would think very hard before buying a spare Console. A complete station is unlikely to cost very much more (if you wait, or look around, for "offers") and many of the other parts may soon become useful as "spares" (for yourself or to pass on).

Cheers, Alan.

[MikeS]

Many thanks for all your excellent guidance - it is much appreciated. I think the best option is to buy two systems and start again.

I hadn't mentioned before, but one of the driving factors is damage to both my wind speed and direction head units. I had erected a pair of coaxial poles from a disused radio mast - like a 25' jumbo telescopic aerial. Normally an oh-so-essential locking pin was employed together with a friction lock to keep the top mast up and allow the sensors to be as clear of confused wind as possible.

However during a recent battery change, said locking pin remained in my pocket! That night's heavy wind caused the inner pole to slide vertically downwards at speed until it hit the deck, at which point it stopped. However the delicate arms on the anemometer and direction sensor didn't!

So I need a replacement set of sensors anyway! I appreciate that Maplins are a good source of very reasonably priced replacements [unlike many other suppliers] but it seems to be a good opportunity to re-establish the system properly.

Many thanks again, I am indebted to you all and feel humbled by your kind responses.

Cheers.