Sébastien Bouillon <sebastien.bouil...@gmail.com> writes: > This is an important criterion that I hadn't thought of taking into > account. Meteostick does not fit this criterion > > I ask myself 2 questions : > - When the raspberry is turned off and on, does the data-logger > automatically return any missing data? I read that it was interesting to > put an RTC module on the raspberry. Is it to avoid problem in this type of > situation?
When you have a Davis in-console logger, and you turn off the weewx computer, and wait a few hours: The logger continues to record archive records (typically the interval is set to 5 minutes). When the weewx computer starts, it obtains from the datalogger the archive records that are in the datalogger and not in the weewx database, and puts them in the database. It is true that a computer running with the wrong time and running the weewx code to extract archive records causes a lot of trouble. So the real requirement is that the computer have the right time before it runs weewx. On normal computers, there is a "RTC" which is a clock with a battery and it is read at boot, so the time is close. On a RPI, or similar low-end single-board devices, these are often not present. Depending on OS and configuration, time at boot can be in 1970, around the time the computer was last shut down, or probably something else. The two approaches discussed on the list are: Get a RTC device for the RPI. They don't cost much, and then the time is correct (close enough) at boot. This is the standard approach and the most frequent recommmendation. Set up NTP, and write a script that makes sure that the computer is synchronized before starting weewx. (This is what I'm doing.) (It's not clear to me that the lack of clock has to be a problem, as the archive records have timestamps, but that's a separate discussion that needs a patch to make it work anyway, not ungrounded discussion.) > - Is it necessary to regularly update the Davis data-logger firmware: > https://support.davisinstruments.com/article/o3dfmlmgsp-weather-link-ip-data-logger-firmware-1-1 > > -5-windows I have never updated firmware on my serial logger. The logger is plugged into the console and has a serial attached to my weewx computer. Therefore my logger does not talk to the Internet at all (which I think is a feature!). The Weatherlink IP is a more complicated device that talks to the internet, so there being firmware updates makes sense. It seems there is now "Weatherlink Live": https://github.com/weewx/weewx/issues/412 and I am unclear if one can use it without the cloud (meaning if you firewall it from Davis's systems, will it still work locally). -- 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/rmilfl8jted.fsf%40s1.lexort.com.
