Sandaysoft

Hi

I am very new to weather stations and weather station weather software in general. I have been asked to setup a weather page for my gliding club. We already had WS-2355 station. Anyway, it would seem to me that the software that came with it is rather outdated, 2002 and in beta. Also for reasons I do not understand keep the CPU working hard. This seems strange as poling the serial port should not take too many cycles.

Anyway I have found Cumulus (here http://www.users.on.net/~freespirit/weather) and I really like the look. The problem I am having is that Cumulus is not displaying pressure. I should point out that all the external sensors are on a post some 200 km west, so I only have the indoor sensors. Temperature and Humidity are displaying fine, but pressure is not (in Cumulus).
I have read the FAQs and it seems that Cumulus will reject data that does not make sense and this could be my problem. The station itself displays Absolute and Relative pressure that is only couple of hPas apart, but the HeavyWeather app shows the relative pressure the same as the station but the first digit is 7 rather than 1 (7001.6 rather than 1001.6).
So I had look at the debug log log in Cumulus and and whilst I do not understand it fully it appears that the communication between the station and the PC is OK, but I wonder about the following:


1219.282 : 9:05:33 PM WS2300: Reading relative pressure
1219.454 : 9:05:33 PM WS2300: data valid, length = 3
1219.454 : 9:05:33 PM WS2300 data: 15 00 27

1219.454 : 9:05:33 PM WS2300: Reading absolute pressure
1219.641 : 9:05:33 PM WS2300: data valid, length = 3
1219.641 : 9:05:33 PM WS2300 data: 95 99 10

If anyone could help me with this, I would appreciate it

Cheers

Paul

It looks to me like the decodes of those readings are:

Relative=11001.5 hPa
Absolute=10636.5 hPa

so Cumulus will be discarding the figures as unrealistically high.

_________________
Steve
Sanday Weather
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Thank you for your reply Steve. Whilst I do not know how to decode the numbers, I do know that the HeavyWeather programs decodes the absolute pressure correctly, but the relative pressure is way off. Yet according to your decode of the log, they are both impossible but relatively close.

I guess the question for me is where do I go from here. Is the station giving erroneous data, which I see as unlikely, assuming that the display on the station is reading the same memory location in its memory table as Cumulus attempts to read.

Just to be sure, and I do not wish to question your expertise, but are you sure that 15 00 27, decodes to 11001.5 and 95 99 10 decodes to 10636.5. The initial codes seems so different to give so close an answer. I have tried to work through this website http://www.lavrsen.dk/foswiki/bin/view/Open2300, but I did not find how to convert (I do not code in C).
If the error is with the relative pressure only as the HeavyWeather application indicates, it may give me something more to go on.

Again, thank you for your time


Cheers

Paul

The decode details are here: http://www.lavrsen.dk/foswiki/bin/view/Open2300/OpenWSMemoryMap

I'd forgotten that it uses BCD, sorry. The decode is:

Abs: 999.5
Rel: 7001.5

So the problem appears to be the sea-level calibration in the station.

_________________
Steve
Sanday Weather
----------------------------------------------------------------------------------------------------------------------------------
Like Cumulus and want to support it? Please donate!

Thank you. I have now "wound" the station's relative pressure back through 6000 hPa and the heavyweather software shows the correct value, but more importantly the Cumulus software is also happy and displays the correct value. I guess a factory reset would also help, but I am not sure what it is. I doubt that anyone wound it up, so i am guessing some memory corruption must have occurred.

Cheers


Paul