This Loop2 packet disc has, I believed solved my issue. I was using the loop1 packet, even though my console and it's firmware version does support it.
I had been using a VERY old version of weewx up until a couple of months ago when I upgraded and put it on a raspberry pi. So far so good, setting it to use the loop_request = 2 seems to be working Thanks! Now I can deal with fine tuning my altitude and calibration. This thread has been a big help! On Tuesday, January 12, 2021 at 3:56:48 PM UTC-8 gjr80 wrote: > Just to clarify, the LOOP2 packet actually includes all three pressures. > So if using loop_request = 2 you will get all three pressures from the > console in both loop packets and archive records. Nothing will be > calculated. The combined hardware/software archive record issue occurs when > using loop_request = 3 and the stream of loop packets emitted by the driver > then consists of an alternating mix of barometer only packets and > barometer, pressure and altimeter packets. > > Gary > > On Wednesday, 13 January 2021 at 07:55:18 UTC+10 galfert wrote: > >> For anyone confused or not able to follow along....here is the premise of >> what Gary and I are discussing. >> >> Davis LOOP1 data in terms of barometric pressure only sends corrected sea >> level pressure. >> Davis LOOP2 data in terms of barometric pressure only sends station >> pressure (atmospheric pressure). >> >> CWOP requires Altimeter pressure which needs to be calculated. The best >> way to calculate Altimeter is to have station pressure (atmospheric) that >> you only get from LOOP2. If LOOP2 is not available (not turn on or using >> old firmware) then the station will only send sea level pressure to WeeWX. >> This will then require WeeWX to back track and try and figure out what >> station pressure is ...and then use that value to then calculate Altimeter >> and that is not very accurate of a process. You can't send LOOP1 sea level >> to CWOP...not the same. >> >> >> On Tuesday, January 12, 2021 at 4:49:05 PM UTC-5 galfert wrote: >> >>> Well then this seems to be a big limitation for any Davis station that >>> is not using a WLL! Seems like the WLL is a better solution than other >>> loggers and then ending up with a mess of combined calculated and received >>> values for barometric pressure. Unless it is possible to set things so that >>> Altimeter is only calculated during LOOP2 reads, and to only accept sea >>> level during LOOP1. I'm not sure if that makes sense or if it is even >>> possible, nor what ramifications messing with all this entails nor what the >>> other undesired results may be. >>> >>> Bottom line....seems like WLL is a better way to get complete live data >>> from the station. >>> >>> On Tuesday, January 12, 2021 at 4:36:03 PM UTC-5 gjr80 wrote: >>> >>>> I have no WLL experience so short answer is I don’t know. >>>> >>>> But the loop_request setting is a vantage driver setting, as far as I >>>> know you need to use a different driver for WLL. Also, there are a number >>>> of WLL drivers; looking at one just now I see it appears to emit pressure >>>> and altimeter, though as I said I don’t know enough about WLL to draw any >>>> conclusions. >>>> >>>> Gary >>>> On Wednesday, 13 January 2021 at 07:22:28 UTC+10 galfert wrote: >>>> >>>>> Gary, >>>>> That is very interesting and possibly important information. Is what >>>>> you mention dependent on the type of logger used? Meaning is the data >>>>> switching (LOOP1 / LOOP2) still an issue with the WLL? >>>>> >>>>> >>>>> On Tuesday, January 12, 2021 at 4:14:00 PM UTC-5 gjr80 wrote: >>>>> >>>>>> Assuming can be a dangerous business! If you have not specified >>>>>> anything for loop_request then you will be using LOOP1 only (the >>>>>> default), >>>>>> whether that is the ‘best available format’ depends on your >>>>>> circumstances I >>>>>> guess. Should you happen to specify loop_request = 3 in order to get the >>>>>> best of both worlds (by alternating between LOOP1 and LOOP2 packets) be >>>>>> aware that this can cause WeeWX loop packets to alternate between >>>>>> hardware >>>>>> provided and software calculated values for station pressure and >>>>>> altimeter >>>>>> (and archive records will then have a blend of both). If you do use >>>>>> loop_request I suggest you carefully read the loop_request stanza >>>>>> <http://weewx.com/docs/usersguide.htm#%5BVantage%5D> in the User’s >>>>>> Guide. >>>>>> >>>>>> Gary >>>>>> >>>>>> >>>>>> On Wednesday, 13 January 2021 at 06:12:20 UTC+10 [email protected] wrote: >>>>>> >>>>>>> >>>>>>> > If you don't have the latest firmware then you may not have Loop2 >>>>>>> data. Not >>>>>>> > having Loop2 data will inhibit greater Altimeter calculation by >>>>>>> WeeWX >>>>>>> > because station pressure will be missing and it will have to work >>>>>>> backwards >>>>>>> > and that is less accurate. Better to send the software station >>>>>>> pressure >>>>>>> > which is done by having Loop2 data. >>>>>>> >>>>>>> According to the Davis site the latest firmward for the Vantage Pro2 >>>>>>> is >>>>>>> 3.15 and wee_device reports my console is at 3.15. I have not >>>>>>> specified >>>>>>> which LOOP data WeeWX is to use as I assume it is coded to use the >>>>>>> best >>>>>>> available format. >>>>>>> >>>>>> -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/97e5eca0-28cf-4dc5-b389-042bd3b242c0n%40googlegroups.com.
