Cumulus Support

From another forum ..

http://www.wxforum.net/index.php?topic= ... g98829#new

Very interesting...

I dont know Davis that well, so if someone can put it in idiot terms for me

Does it mean, that you can have a davis weather system, connected to your pc, without the need for the datalogger, and all its gonna cost is $15 ?

Rob, in short terms, yes...

As you might have read somewhere else, the Davis Instruments weather stations are sold without any means (cable or data logger) of connecting the console (the receiver) to a computer. After purchasing a Davis weather station, one must also purchase one of the WeatherLink adaptors:
- WeatherLink Serial (for connecting the console to a computer serial port),
- WeatherLink USB (for connecting the console to a computer USB port),
- WeatherLink IP (for connecting the console directly to the Internet),
- WeatherLink for Irrigation Control,
- WeatherLink for Emergency Response Team,
- WeatherLink for APRS,
- WeatherLink for Mac OSX.
Most adaptors are retailing for (around) $170 US (although some are more expensive).

So, if someone could come up with a really inexpensive solution to replace the expensive Davis adaptor, then that would a good idea - and once that adapter has been properly designed and tested, it could be produced in China to bring the costs even further down...

Bear in mind that this only gives you the PC connectivity feature of Weatherlink, and not the logger feature.

So (and please forgive me for being dumb)

This means, you connect the station to the PC, and just run your cumulus software, and hey presto data onto your pc then onto your website?

Sorry for the questions, but this is an interesting development

steve wrote:Bear in mind that this only gives you the PC connectivity feature of Weatherlink, and not the logger feature.

Well not quite true actually, once you have the data it would be quite straightforward to add an archive feature, it might mean a different approach to extracting it but that would be a small price to pay.

Also there have been other 'dataloggers' which work - I have one! It was sold by a company (long gone) called Bluewave and it is what I have used for my VP1 for the past 5 years, so it can be done and at a better price than Davis.

Stuart

steve wrote:Bear in mind that this only gives you the PC connectivity feature of Weatherlink, and not the logger feature.

Steve, I beg to differ! With a properly designed software and an inexpensive serial/USB adaptor, all the data from the internal console memory could be downloaded - in the same way that it is being done now with an expensive (overpriced) Davis WeatherLink adaptor and a buggy DLL interface.

If this project moves forward (with someone helping in creating/designing a software) it would mean direct communication with the console's internal memory without the need of a limited DLL (to squeeze out every bit of data) - in the case of Cumulus, it would mean that you would be able to include the communication routines right into Cumulus with no additional interface needed (no need to talk to a DLL) - it is my understanding that Brian Hamilton is following very closely the evolution of that project...

robynfali wrote:This means, you connect the station to the PC, and just run your cumulus software, and hey presto data onto your pc then onto your website?

Almost...
If and when the source code for a routine (small program) to communicate (bi-directionally) with the internal memory of the Davis console (more likely, the work will begin with the Vantage Pro console to eventually include the Vantage Vue console), that routine could eventually be included into any weather program - thus direct communication between, for example, Cumulus and a Vantage Pro console would be performed with no other 'obstacles' other than that inexpensive 3.3 volts FTDI Basic (FTDI FT232RL USB to serial IC) breakout board and some communication routines...

robynfali wrote:Sorry for the questions, but this is an interesting development

Do not be sorry, you are just trying to inform yourself.
Indeed it is an interesting development ... as long as a few more informed (qualified) software designers get involved with the project ... and as long as Davis Instruments does not try intimidating the people involved through legal obstacles...

And I notice that Stuart sees it my way...

broadstairs wrote:Well not quite true actually, once you have the data it would be quite straightforward to add an archive feature,

Sorry, I must have misunderstood; I didn't appreciate the fact that the $15 board that Rob asked about also contained memory so it could work as a logger.

gemini06720 wrote:If this project moves forward (with someone helping in creating/designing a software) it would mean direct communication with the console's internal memory without the need of a limited DLL (to squeeze out every bit of data) - in the case of Cumulus, it would mean that you would be able to include the communication routines right into Cumulus with no additional interface needed (no need to talk to a DLL)

But Cumulus doesn't need to use the DLL now; I could have chosen to drive the serial interface directly, as most other software seems to do. Indeed, as I've done with Cumulus 2.

My understanding of this thing is that it opens up the standard Davis serial protocol (hence the guy referring to the Davis serial protocol spec), in the same way that a standard Davis Weatherlink adapter does, so any software which already understands the Davis serial protocol (e.g. Weather Display, the Davis DLL, and Cumulus 2) would be able to drive it without any other drivers being needed?

steve wrote: ...Sorry, I must have misunderstood; I didn't appreciate the fact that the $15 board that Rob asked about also contained memory so it could work as a logger.

Steve I do not think the FTDI Basic breakout board (FTDI FT232RL USB to serial IC) contains any memory - I could not find that information on the SparkFun Electronics web site.
But why would such a board need an onboard memory - the weather data is kept inside the console internal memory - the WeatherLink, to my understanding, is simply used as an interface between the console internal memory and an external source, such as a computer or a modem or the Internet - I do not think the WeatherLink adaptor has any storage memory.

gemini06720 wrote:But why would such a board need an onboard memory - the weather data is kept inside the console internal memory - the WeatherLink, to my understanding, is simply used as an interface between the console internal memory and an external source, such as a computer or a modem or the Internet - I do not think the WeatherLink adaptor has any storage memory.

The archive memory is in the Weatherlink module. Hence the comment in DeKay's first post: "I would think that any software that talks to the datalogger should work with my technique, with the exception of retrieving data stored within the non-volatile memory of the datalogger itself."

Obviously, once you can interface to the station, you can develop a logger, but my warning was that the $15 solution gives the PC connectivity but not the logging ability of Weatherlink. You either need additional hardware, or you need to run your software 24/7.

The datalogger does indeed contain the archive memory, in my case its a larger memory on the Bluewave logger. Correct there is no memory on that board but that was my point once you have the interface you could develop your own archive as an add-on. It would need to be on the interface board so it worked when the PC was off otherwise your station would be no better than the ones with no archive.

Stuart

Way to go!