Author Topic: Which wifi weather station?  (Read 5098 times)

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Offline sanpiran

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Which wifi weather station?
« on: October 06, 2014, 12:45:56 PM »
Having had a couple of LCD type display weather stations, (now defunct) I decided that I really need just a true wifi transmitting sensor array, the data to be received by my wifi enabled Windows 7 laptop, with suitable software installed. As far as I can see this is not an option, unless I have missed something. All the units have a separate display and I really don't want yet another one.
This seems such a simple way forward yet I have not seen one advert with such a system.
Has anyone any ideas please?

Offline johnd

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Re: Which wifi weather station?
« Reply #1 on: October 06, 2014, 01:00:33 PM »
I think the problem is that most WiFi adapters need more electrical power than can be reliably supplied by a small and inexpensive solar PSU. So the only option would be to use power derived from an AC mains adapter and then taken out to the sensors. In many situations this would just be too limiting for good sensor exposure.

The wireless on units like Davis relies on being powered off most of the time and just powering up very briefly eg every few seconds to transmit a data packet. This way a very little power can go a long way. But it does require transmitter and receiver chips that use special protocols to support this type of intermittent operation. AFAIK this isn't how most networked WiFi works.

But a solution like MeteoStick used with Davis sensor transmitters might come close. It wouldn't be WiFi but would amount to what you're seeking to do.
Prodata Weather Systems
Prodata's FAQ/support site for Davis stations
Includes many details on 6313 Weatherlink console.
UK Davis Premier Dealer - All Davis stations, accessories and spares
Cambridge UK

Sorry, but I don't usually have time to help with individual issues by email unless you are a Prodata customer. Please post your issue in the relevant forum section here & I will comment there if I have anything useful to add.

Offline Hugh_Everett

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Re: Which wifi weather station?
« Reply #2 on: October 29, 2014, 12:42:19 PM »
In mid September I installed my first ever PWS - a Watson W-8681 PRO. The sensor station sits outside and transmits via proprietary protocol [I don't know the details] to a small (10cm x 20cm) display unit inside the house. The display unit then connects via WiFi to Wunderground to post data (every 10 seconds or so). And to see stuff on my PC I go to Wunderground web-site (I don't link my PC directly to the display unit). And that provides all I need - including access to all data tabularly and graphically on my PC. So I guess my experience, having researched beforehand, is that what sanpiran is asking for isn't offered.

Yes, I agree with johnd that the power that would be required by WiFi built into the sensor station couldn't be provided by the batteries in the sensor station - or maybe the batteries would have to be replaced every <small unit of time like a week>.

Offline pfletch101

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Re: Which wifi weather station?
« Reply #3 on: October 29, 2014, 03:52:42 PM »
My (ideal) requirements were similar to sanpiran's, and I wasn't able to find anything that met them, either, so I ended up with my Davis system, which does the job that I wanted to do, albeit with more cost and complexity that I wanted. I am sure that the power drain of a typical WiFi chipset is a big part of the issue. Of potential interest, however, is the fact that WiFi devices are available (my setup includes one - see http://www.wxforum.net/index.php?topic=18758.msg215250#msg215250) which seem to be able to function without requiring an excessive amount of power. This package contains a fairly small rechargeable battery that only needs to be recharged every 2-3 months with the device reporting every 5 minutes, about 16 hours/day. I imagine that it could function indefinitely if intermittently powered and recharged by a standard Davis solar array. Granted that a full weather sensor array has more data to transmit at every connection, it would still now seem that it should be feasible to develop the device that we were looking for - hopefully, someone will!
Vantage Pro 2+ connected to Raspberry Pi running weewx by means of Meteo-Pi - data incorporated in domestic energy production (PV) and use monitoring system.

Offline johnd

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Re: Which wifi weather station?
« Reply #4 on: October 29, 2014, 04:52:16 PM »
There are low-power WiFi modules around, like the Gainspan ones:

https://s3.amazonaws.com/site_support/uploads/document_upload/GS1011M-PB.pdf

But it would need someone with some electronics development expertise to build a unit based on something like this (there are other makes too), work out how to minimise the current drain and then build up the unit into an overall sensor/transmitter package which is properly weather-proof and capable of robust, long-term operation in adverse climates. It's not really enough, other than proof of concept, to demonstrate that such a unit will work under favourable conditions - to be considered a 'proper' serious weather station, it has to be deployable at most locations worldwide and deliver eg at least a 5-year service life.

I did look into this a year or two back, can't find the detailed notes right now, but IIRC what made these modules low-power (beyond careful circuit design) is that they were specially configured to be able to use a low-power sleep mode, but from which they could wake up, quickly reconnect to the network and transmit a data packet before sleeping again.
« Last Edit: October 30, 2014, 05:13:37 AM by johnd »
Prodata Weather Systems
Prodata's FAQ/support site for Davis stations
Includes many details on 6313 Weatherlink console.
UK Davis Premier Dealer - All Davis stations, accessories and spares
Cambridge UK

Sorry, but I don't usually have time to help with individual issues by email unless you are a Prodata customer. Please post your issue in the relevant forum section here & I will comment there if I have anything useful to add.

Offline pfletch101

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Re: Which wifi weather station?
« Reply #5 on: October 29, 2014, 05:25:03 PM »
I did look into this a year or two back, can't find the detailed notes right now, but IIRC what made these modules low-power (beyond careful circuit design) is that they were specially configured to be able to use a low-power sleep mode, but from which they could quickly wake up, reconnect to the network and transmit a data packet before sleeping again.

That (waking up from a low-power sleep mode for only long enough to transmit a data packet) is, at least in principle, how the TH sensor I use and write about in the thread I pointed to works. It is a fair bit more complicated than that in practice, of course, because the device has to be able to recognize and deal with the possibility that the destination of the data packet (a program running on a computer elsewhere on the network) is not available, and (ideally, at least) to store the data locally so that it can catch up when the destination program is running again.
Vantage Pro 2+ connected to Raspberry Pi running weewx by means of Meteo-Pi - data incorporated in domestic energy production (PV) and use monitoring system.

 

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