$latest is the last archive record in the database. So, $latest.windSpeed is the last wind speed in the database, whether null or not.
Unfortunately, there is no tag meaning "last non-null" value. You'd have to write a search list extension. But, I find the semantics of what you're trying to accomplish a little hazy. If you're satisfied with 15-minute old data, why not just sample every 15 minutes? To answer your other question: the presence of null values will not affect averages. -tk On Mon, Feb 10, 2020 at 9:01 AM wysiwyg <[email protected]> wrote: > Hi There! > > I am working on my wind sensor currently, so far I have tuned my data to > be emitted the following way (My weewx record interval is 5min): > > *When there is some wind:* > Every five 5min, sensor will emit average windspeed/dir over last 5 > minutes and max windgust/gustdir observed on a 10sec interval during the > last 5 minutes. > I tuned this way because I want to make sure weewx will record any extreme > windgust I measure. > If I send more than 1 sample of windgust in 5min period, weewx will > average them to build its database record. (as far as I understood) > > *When there's no wind:* my sensor will emit a zero speed value every > 15min to save battery, so it will miss ~2 database record over 3. I guess > it's not a big deal as there's no wind. > While writing this, I wonder if those missing "0" speed samples can affect > some calculations, like average wind ? > > > > Anyway: due to those timings, It happens that I have no wind data on > current database record: meaning $current.windSpeed will sporadically give > N/A value (more often when there's no wind). > I was expecting $latest.windSpeed to give me the last value recorded (in > my situation 5-15min ago). > But apparently, it's not working this way ? > Is there a workaround possible ? > > Best regards, > Frederic > > > > > > > -- > 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/f5ac6ea6-caff-48e6-86de-1aa039f00541%40googlegroups.com > <https://groups.google.com/d/msgid/weewx-user/f5ac6ea6-caff-48e6-86de-1aa039f00541%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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/CAPq0zEB6Cs%3DT1zNW_EwSTZqn1gmR-AuDFQO6EkX-7d0d5yBjcw%40mail.gmail.com.
