Sandaysoft

Hi Charlie,

First of all thanks for your reply and thanks again for your work in this hard project.

I do not know if this kind of input is what you look, but I will try to answering some of your questions to guide you better in this project. BTW, I also like much that you take into consideration not only your needs for this project, but needs of other possible users.

In the budget range of personal weather stations, basically what I personally look is the basic functions/features, like what the FO WH-1080/3080 stations have. Indoor Temp/humidity; Outdoor Temp, Humidity, Wind speed and direction, Pressure, Rain. Solar readings not a requirement but a plus.

Having some kind of display or console to see the readings without a computer is important, in case I loose the PC (this becomes more important during events like hurricanes). But I guess if the price is right, one could manage with just the PC and cumulus reading.

I have mostly used weather stations that are wired to an external sensor, and send wireless the data to the internal sensor/console; and that is the setup I mostly prefer. But again, if price is right, I guess a complete wired station (like yours) will not be a "deal breaker" despite my preference, if all other requirements are to my liking.

The ability to get replacement sensors (easy and cheap) do would be a great plus also. Stations do require occasional maintenance and is sometimes frustrating to buy a 100USD station to then replace a small one component at a price of 50USD plus shipping.

Thinking wild here... maybe having a station capable of both, completely wired and wireless from outdoor to indoor might be a good feature But I guess will also add more on the development and selling costs...

BTW, the reason I like more the set up wired sensors in the outside, but wireless to the inside (like the FO), instead of all wired like your, is a simple logistics one I find like you that wired is less prone to error than wireless, but wireless is easier to get inside the home without drilling holes in the walls or windows... So I find the best middle approach is like what the FO stations do... all outside sensors wired to the External TX and then an internal RX to receive that wireless signal.

I also like stations (like the FO) that have the sensors wired to that External TX Unit, but is not all in just one big piece. That way one can place better the sensors, like raising the wind instruments higher in a pole and/or putting the outside temperature sensor in the shade.

Well hope input like this is what you were looking for. I am not saying build your station like this, I am just letting you know what a customer like me would be normally looking, based on my personal preferences. Hope I understood what you want. I also apologize for any part of what I say you do not understand. Although I do have a very good written and oral english, I do must accept english is not my primary language. And I sometimes may forget a word or two in moments like this; and those words may be crucial for the communications to flow.

If I can help in any other way with more information, or clarify anything I told here, I am at your orders...


Francisco

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Thanks, Francisco (and Ron and Mark too) for your feedback, it's great to have someone to exchange ideas with.

Cost is certainly going to be a challenge. Since I'm building a few units in a local manufacturing facility instead of making millions of units in China, I think there's no way to come in under the F.O. in terms of monetary cost. However not having to climb on my roof when it's full of snow, or spend an hour editing out rain spikes, or redoing cold solder joints, is worth a few extra pieces of silver to me at least.

I'm also hoping to leverage parts people may have bought in the past (1-wire sensors, rain gauges, etc.) to make the overall cost lower. I may offer some competitively priced sensor devices if there’s some interest, but for now most of us hobbyists have a box or two of bits in the workshop gathering dust that we can leverage to keep the cost down.

I wrestled with wireless for a long time, and for now at least, decided against it for several reasons. First, it’s a huge source of data errors. There are certainly ways to make the link more robust, and there are error detection and correction algorithms, but it’s another thing to go wrong. Then there are power issues. Wireless implies batteries, which imply serious design constraints around power consumption. Certainly doable, but months more work. Next there are regulatory issues. Once you start transmitting things, you find that every country has different frequencies and allowable emissions limits. Here in Canada, I can do pretty much anything under 100 mW effective radiated power without license. Not so in a lot of the rest of the world, and applying for a single license would destroy any hope of having something at a reasonable cost.

So if I stay away from wireless, this becomes a standard low voltage electrical product with effectively no certifications required, other than declarations around EMC and safety. Simple and more robust, and supplying the data when you want it.

Do you think lack of wireless is a “show stopper”?

Lack of wireless would certainly make me think very hard before buying a weather station. I wouldn't enjoy digging a trench out to the sensors for the cable!

Would you not need a CE mark if you were to sell these in Europe?

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Steve
Sanday Weather
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Hi Charlie,

As I said before, lack of wireless will not be a "deal breaker"... but surely will be a "-1" in the evaluation.


Francisco

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The CE mark is a good question. As near as I can tell, there is no requirement on this sort of gear. It's certainly below the definition of low voltage devices, has no mains connection, no RF transmitter, and attaches to a computer somewhat like a mouse or keyboard. I suppose you could make a case for an EMC Class B requirement, basically not further degrading the computer's compliance, but that's about all I could find. Possibly ROHS for materials (lead free soldering).
CE is a self declaration for this sort of gear; basically stating what it meets and does not.

Charlie,

Since I am licensed radio amateur, Telecoms Technologist and work for a small meteorological unit in a research center, it seems a very interesting project to my eyes

Have you tried this part: http://www.sparkfun.com/datasheets/RF/HAC-UM96_manual.pdf for making your station wireless? I'm never used or tested this part by myself, but I heard good comments from some former students.

Last year we purchased at my lab 4 XBee Pro 50mW RPSMA - Series 2 (ZB) units from a http://www.digi.com local vendor for a small project that we are working now and the performance was pretty good in the initial testings. (50mW output, +17dBm)

These boards are very easy to integrate into existing systems and are fully FCC certified.

Hope this info can be useful for you.

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Marco-Luis
YV1HX
Cabimas, Zulia, Venezuela
http://www.twitter.com/meteoven

Thanks for the suggestion, however adding $100 cost ($44.95 + shipping per end) before integration to convert 1-wire to RS-232 would be a deal breaker, I think. The concept was to utilize those 1-wire modules most long time weather hobbiests played with at one time or another, in a product that could be used with Cumulus. 1-wire is really only the transport protocol, so making it wireless sort of defeats the purpose.

While for several people like Steve, wireless is a must, most stations are on the sides and/or roofs of our homes where running a wire takes a bit of time, but is not a big deal... and a small price to pay for a robust system that no longer includes data spikes, lost contact errors, etc. etc. that plague low cost systems.

I have not seen a lot of interest here, so either Cumulus people tossed those modules, or the 1-wire folks love their stations more than Cumulus and use other software (hence never reading this forum). A loss I think, when you CAN have both.

What about a "add-on wireless module" for those people that cannot go wired?



I agree totally with your point of view.. at home my WS-2310/15 (in wired mode) sometimes got a spike, fortunately filtered out thanks to Cumulus "Spike removal" tool.

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Marco-Luis
YV1HX
Cabimas, Zulia, Venezuela
http://www.twitter.com/meteoven

I'm surprised that there hasn't been much interest, given the number of requests I've had in the past for 1-wire support. Perhaps not many people read the 'homebuilt' section, or maybe they don't understand what it is you're offering? I'm quite happy for you to 'sell' your product here; you did have the courtesy to contact me privately to discuss it before you even mentioned it publicly. Not everyone does that before posting their 'click here to buy now' links

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Steve
Sanday Weather
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Agree with Steve ^--^

Just a quick reply but, I would be interested in one of your Wired Systems.

Thanks

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Jason Duncombe
La-Crosse WS2300 (Wired & Serial) - Cumulus V1.9.3
Check out the Weather Blog

I'm interested and keeping a watchful eye, but not in a position to buy anything at the moment - now if the FO were to 'die'

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Mark
Wilmslow Astro Weather

You could shoot it Mark, that's what I did with mine. Of course, it had an organ donor card, so the wind vane, anemometer, and rain gauge were re-purposed to the new system.
Speaking of which, are there any recommendations for better units?

Charlie, how about those sponsored on the Hobby Boards weather web pages - certainly not the lowest priced items.

Replacement parts for the Davis Vantage Pro weather stations could also be 'possible candidates'...

You did write that the FO (and similar) stations were not very reliable - all those mass-produced poor quality control Asian weather stations...

If i missed this somewhere along the way, sorry.

But, am I correct in assuming this is going to to connect via 1 wire?

And, does Cumulus currently support 1 wire?

Duke

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Duke

Nightingale Weather PHP
Eastleigh, Hampshire, UK

It uses 1-wire sensors, yes.

No.

Charlie's device emulates a Fine Offset station.

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Steve
Sanday Weather
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