We may need Tom, mwall or Gary to offer their insight on the weewx internal code question.
I'm using the Meteostick driver as well however my hardware is a Moteino (Arduino) with Meteostick emulated code <https://github.com/mcrossley/VPTools> on it. So my hardware is not an exact like-for-like with your setup, however my driver is the same. I don't seem to be having the issues you are reporting. My values all seem to be within their respective boundaries? See my attachment which is in inHg and mbar for comparison. I think your question is valid - if this was a problem with weewx it would be a much bigger problem. Which goes back to seeing how you can troubleshoot your Meteostick directly. Every 30 seconds it outputs a "B packet" which <https://www.smartbedded.com/files/manual-en.pdf> contains the pressure of your station. We could modify your driver to log this to a text file so you can do a manual check of those values over the course of a few days? Not sure how else to troubleshoot this. On Thursday, August 8, 2019 at 4:33:04 PM UTC-4, Brezentrager wrote: > > Yes, that's also my understanding. > The "pressure" line in my screenshot should be the original pressure > reading of the stick, isn't it? > > My problem is that I don't know enough about what "magic" weewx applies > when calculating the barometer values out of pressure. > When looking at the code of weewx (see below) I can see that the weewx > calculation has quite an effect on the barometer value. > A temp-difference of 10C results in approx 2.5mbar difference in > 'barometer pressure'. > > [image: Bildschirmfoto 2019-08-08 um 22.16.05.png] > > > My values therefore seem to be "correctly calculated". > Still, I'm surprised to see this up and down. But when looking at the > code, this obviously has to be that way. Whenever the temperature changes, > the barometer value will also change considerably. > > All other Weewx users should see the same pattern in their barometer data. > Is that the case? > > Manfred > > > > Am Donnerstag, 8. August 2019 21:49:43 UTC+2 schrieb Pat: >> >> My initial question was to try and isolate the readings (to see where the >> problem is)... Does the Meteostick have a way to see its values without >> weewx? (web ui? serial port?) Trying to see if the stick is the problem or >> if it's weewx. >> >> The driver looks like it expects "pressure" from the Meteostick, and >> submits that to the loop >> <https://github.com/matthewwall/weewx-meteostick/blob/master/bin/user/meteostick.py#L643>. >> >> As I understand it StdWxCalculate >> <https://github.com/weewx/weewx/blob/master/bin/weewx/wxservices.py#L19>will >> calculate the barometer >> <https://github.com/weewx/weewx/blob/master/bin/weewx/wxservices.py#L237-L240> >> >> based on the pressure value in the LOOP. >> >> >> On Thursday, August 8, 2019 at 3:38:53 PM UTC-4, Brezentrager wrote: >>> >>> Yes, the pressure values come from the Meteostick. I'm less concerned >>> about the actual level of the barometer values - that's something I can >>> calibrate. >>> I'm more concerned about the ups and downs that heavily correlate with >>> my temperature and humidity values. >>> >>> Am Donnerstag, 8. August 2019 21:35:27 UTC+2 schrieb Pat: >>>> >>>> Actually this is probably a bad comparison since I think the Meteostick >>>> comes with it's own barometer on the stick itself - so the values won't be >>>> identical. >>>> >>>> >>>> On Thursday, August 8, 2019 at 3:25:37 PM UTC-4, Brezentrager wrote: >>>>> >>>>> The values on the console are generally lower. Currently - Console: >>>>> 1015.1 // WeeWX: 1017.9 >>>>> The difference gets bigger in the morning and smaller in the >>>>> afternoon/evening. >>>>> >>>>> >>>>> Am Donnerstag, 8. August 2019 21:19:42 UTC+2 schrieb Pat: >>>>>> >>>>>> Just curious how these values compare against your station's console? >>>>>> >>>>>> >>>>>> On Thursday, August 8, 2019 at 2:46:23 PM UTC-4, Brezentrager wrote: >>>>>>> >>>>>>> Hi, >>>>>>> AWEKAS doesn't accept my barometer figures since they differ too >>>>>>> much from comparable stations in the region. >>>>>>> >>>>>>> When looking at the issue in more detail I found a suspicious >>>>>>> pattern for my barometer data - see screenshot of last week's pressure. >>>>>>> >>>>>>> [image: Bildschirmfoto 2019-08-08 um 20.04.33.png] >>>>>>> There's quite a big variation between the barometer figures in the >>>>>>> morning (high) and in the afternoon (low). The variation is as big as 5 >>>>>>> mbar - every day. >>>>>>> When comparing this to a station in the neighborhood, those >>>>>>> variations are absolutely unusual. >>>>>>> >>>>>>> When comparing the values to stations in the region, the lower >>>>>>> afternoon values seem to be more comparable (=correct). >>>>>>> >>>>>>> I know that the barometer values have some temperature correction >>>>>>> applied to it. But why is the effect so huge? >>>>>>> The pressure and altimeter values look much more reasonable. >>>>>>> >>>>>>> Did I set up my system in the wrong way? >>>>>>> >>>>>>> As background: >>>>>>> The Meteostick is connected to a RPi (running the latest version of >>>>>>> weewx and Matthew Wall's meteostimk driver). >>>>>>> >>>>>>> Hints and tips appreciated! >>>>>>> >>>>>>> Best, >>>>>>> Manfred >>>>>>> >>>>>> -- You received this message because you are subscribed to the Google Groups "weewx-user" group. 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