Hi Rainer and Gary, thank you both very much for the detailed explanation! I was not aware that the $current tag also provides access to ALL observations of the current record, regardless if they are archived or not.
Is the $current tag the only tag that provides this access? I assume the $latest tag also does? The $span tag would not be able to get values from those fields, since it's an aggregate, right? Just asking because I have added a check for displaying the battery states, like eg. #if $getattr($span($day_delta=1, boundary='midnight'), 'wh31_ch1_batt').has_data which does not really make sense after understanding the internals, it should test against $current. *[...] weewx includes values from the database and the current values of all observations in the current values table, also from those which have not been archived but are still available in memory from what has been provided from the driver [...]* Where is this data actually stored if not in the database? Is there any way to test this out, besides actually using the said driver? Sorry for a load of questions, please point me to the right documentation if I missed something in the guides. Thanks in advance and thanks again for enlighten me about this :) gjr80 schrieb am Dienstag, 27. Juni 2023 um 18:21:54 UTC+2: > David, > > Some answers/comments below. > > On Tuesday, 27 June 2023 at 01:16:51 UTC+1 david....@gmail.com wrote: > > > Signal level observations: All *_sig observations like, wh31_ch1_sig, > wh31_ch2_sig, wh32_sig. I don't understand these: What is the signal > level here? Values seem to be `0` or `4` in that LOOP packet (looks like > battery state fields?). > > > Ecowitt gateway signal levels are a pseudo-signal levels at best; the > number represents the number of the last four data packets from the sensor > that were successfully received/decoded. So most of the time, if the > sensors have a reliable connection to the gateway device, you will see a 4, > on startup you will see 0 and it will ramp up to 4 if all sensors connect > successfully and reliably. The number bears no reference to the sensor > signal level received by the gateway device or emitted by the sensor. > > > So the problem with all these observations is basically (as far as I > understand, please correct me if I am wrong): WeeWX does not know about > them and does not save them to the database (but you will need this data to > show plots of the battery voltages for the last week for example). There > should be two ways to overcome this: > > 1. Add the fields provided by the GW1000 driver to the database, see > http://weewx.com/docs/latest/customizing.htm#Modifying_an_existing_database > 2. Map the GW1000 fields to WeeWX schema fields (see > https://github.com/weewx/weewx/blob/master/bin/schemas/wview_extended.py#L16) > I assume that was somehow done for a short period of time because e.g. > rxCheckPercent or consBaterryVoltage are showing/having data for a few > days!?) > > @Gary I don't quite understand what you have written about that: > > *It is not necessary to do so if only displaying current values (ie values > from the current archive record)* > > > A quick and simplified WeeWX data flow 101. A WeeWX driver gathers data > from a station/sensors and emits loop packets on a regular and frequent > basis. WeeWX accumulates these loop packets and at the end of an archive > period WeeWX synthesises an archive record from the accumulated loop > packets, this record is known as the current archive record. WeeWX saves > the current archive record to database, but only those fields that are > common to the WeeWX database schema and the current archive record. WeeWX > then generates reports. Note, there are usually a number of additional > WeeWX services that 'do things' (eg quality control, calculate derived > values etc) to the loop packets and archive records before they are > accumulated/saved to database. > > When WeeWX generates reports all fields in the current archive record are > available for use in WeeWX generated reports via the $current tag, > irrespective of whether the field was saved to database or not. So if you > wish to include only the current value of a field in a WeeWX report there > is no need to save that field to the database, but if you wish to display > any sort of historical data (eg an aggregate in a report or plot historical > values) for a field you need to save the field to database. For example, > generally folks want to display max/min values of outside temperature or > plot outside temperature over some period so outTemp is usually saved to > database. However, you may only wish to display the current signal level > value for a given sensor using a $current tag so you may chose not to > save the sensor signal level to database. > > So in terms of WeeWX 'knowing about a field' there are two things to > consider. (1) does the WeeWX schema need to include this field, if it does > this can be achieved by mapping to an already existing database field or > adding a new field to the database schema (or a combination of both) and > (2) do any enabled reports need to know about the field, this may entail a > simple config change in a skin config file or modification/creation of a > template. > > > How would you show fields like wh41_ch1_batt from the current archive > record when the data is not saved? Am I missing something? > > > As outlined above, in such a case you can display the current > wh41_ch1_batt value but will not be able to display any historical values > or aggregates nor will you be able to plot wh41_ch1_batt. If you wish to > display any historical values or aggregates or plot wh41_ch1_batt you > need to add the field wh41_ch1_batt to the database or map field > wh41_ch1_batt to an existing, unused database field. > > -- 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 weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/abf92ed8-282f-45f3-b367-c9ee084eee74n%40googlegroups.com.
