Cumulus Support

jim-easterbrook wrote:The sensors transmit data every 48 seconds, the consoles log it every 5 minutes. One of your consoles logged the spike, the other didn't. I'm sure both consoles received the spike.

Yes, I agree. There are generally 6 broadcasts in the 5 minutes and unless the consoles are synchronised, a spike will show on one and not the other. I think before when the spikes coincided, the consoles must have been logging the same transmission ie. synchronised.

Thank you Mark, for superimposing my plots - good idea And yes, there are small spikes still. In fact I'm not using Cumulus (though I don't think that would be any different), I'm using G-Weather, my adaptation of Jim Easterbrook's pywws Linux software.

Gina wrote:In fact I'm not using Cumulus (though I don't think that would be any different), I'm using G-Weather, my adaptation of Jim Easterbrook's pywws Linux software.

If your software hasn't diverged too much, you could try the new 'live logging' routine and save every bit of 'live' data (48 second interval) from both stations just to prove they are the same.

jim-easterbrook wrote:If your software hasn't diverged too much, you could try the new 'live logging' routine and save every bit of 'live' data (48 second interval) from both stations just to prove they are the same.

Thank you Jim, I'll look into that, sounds like just the ticket The data logging side has changed very little. I'm hoping to get more time to continue the development soon, I've had higher priorities lately I'm afraid. I need to read through the pywws Google group postings and assimilate the updates.

I have heaps of temperature spikes, but believe it or not they are all real
Guess having the rad. shield fan-aspirated means the sensor picks up on every little change!

Sometimes I would like the line to be smoother actually

I've been wondering about adding fan aspiration to my screen. How much difference does it make, are temperature and humidity a lot more accurate? I would imagine it makes a difference when there's no wind. I have a double roof on mine so I could quite easily put a PC fan in the lower roof.

Gina wrote:I've been wondering about adding fan aspiration to my screen. How much difference does it make, are temperature and humidity a lot more accurate? I would imagine it makes a difference when there's no wind. I have a double roof on mine so I could quite easily put a PC fan in the lower roof.

Hey Gina, I think the main thing about fan aspiration is that the response is a lot quicker. I get the temperature and humidity both changing quickly and get a very spiky 'noisy' dew point line sometimes. I attached today's graph as an example - it was a lovely sunny spring day

The Davis VP2 manual says under sunny conditions at solar noon, their normal shield may read up to 2C high, and with fan aspiration about 0.3C high.

Thanks Dave I think I will add a fan when I get time.

Hmmm... This is getting silly! I find a mod to my hardware that pretty much cures the spikes for a time, then they come back again! So I find another mod that removes the spikes from the plot and again they come back... So I find yet another "cure" but that is only temporary too!

Guess what??? They're back!!! Next... More filtering on the wind sensor inputs. And see if that does anything and if it lasts.

Current remedies:-
1. Earth the mast
2. Screen the cable and earth the screen
3. Decouple the power supply

Haven't had time to do any more investigations just recently but hope to get on it again soon. Meanwhile, here's the latest crop :-

If you can't fix the actual source of the problem itself, have you considered adding something to your software like what Cumulus has, EWTempDiff or something like that...

Yes, I have and I shall probably do that but I'd prefer to block the interference rather than discard the data, if at all possible.

Hi Gina,
I have been having huge temperature spikes on my new system - -0.5 deg to 27 deg in half an hour!! The whole unit is mounted on the TV aerial. I moved the temperature sensor to inside a box hanging from the eves of the house - it was worse. So last weekend it all came down and sits in the middle of the lawn. I connected the sensor and transmitter only (no solar power unit, no external temperature sheild, only the temprature sensor). Perfect results. 24 hours later I connected the solar power for the battery - perfect. 24 hours later connected the wind sensor - 10 minutes later a spike! I am presently monitoring the results on http://clangers.freewebsitehosting.com/trends.htm (I will move sites in due course) but if you look at the latest outside temprature from 1800 yesterday there is a quiet period overnight but as the wind picks up today there are a large number of spikes.
I must note the rain guage is not connected yet. I have not edited the .ini files in Cumulus yet and am resistant at this point.
Can you or someone please explain to me how I go about putting in a capasitor as has been previously discussed - I am Technologically challanged!!
Phil.

Hi Philclem,
Several of us are working on this issue, but it is quite a challenge. It seems that any fix we introduce works fine for a few days and then the spikes return. It's almost like it adapts to the new condition, which brings back the spikes.
The source of the problem is the wind speed sensor, which is on the 2 center leads of the 4 lead "wind" connector. I tried a capacitor across these leads and it was fine for a few days. Yesterday I tried a capacitor across the leads and one to ground on each leg. (It looks good so far, but we'll see). Gina has tried many things as well, with the same "works for awhile, then bad again" results.
I've resolved not to post results until I'm sure the test works this time.
Let us know of anything you discover!

Hi Phil.

As Charlie has said, whatever we do we seems to stop the spikes for a while then they return - so until one of us finds a lasting fix, I don't think I'd bother. I have had many years of experience in electronics, radio, computers and interference issues but this "thing" is proving very difficult and puzzling.

Unfortunately, I don't have much time to put into this but I'm now setting up the latest version of Jim Easterbrook's pywws software with it's "livelog" 48 second data logging which gives six times the logging frequency as the stored data in the console. This should give six times the chance of seeing any spikes, thereby reducing the time it takes to see the effects of any "fixes".

Today I noticed a spike in the temp graph (1153hrs) and subsequent record highs recorded. These highs are not reflected in the monthly log file.

Shutting down cumulus and restarting fixed the graph but I need to edit the relevant files to remove these entries (Will wait until after tomorrows 9am rollover before I do this). Graph below. Now the only thing I can put this down to is that at about that time I plugged my iPhone into the station notebook's usb to charge it and maybe at the time cumulus was reading the station console.

Any thoughts?