> > In essence MQTTPublish would be creating its own ‘archive record’.
I'm struggling to figure out the benefit of this, would this be to reduce the publishing rate? or? On Thu, 9 Jul 2026 at 05:48, [email protected] <[email protected]> wrote: > Interesting ideas. Time to move this somewhere else. I haven’t got far on > any of this, but I think being able to publish on an interval bigger than > the loop interval, but smaller than the archive interval might be the most > interesting/useful to start with. > Leveraging WeeWX accumulators it shouldn’t be too difficult. In essence > MQTTPublish would be creating its own ‘archive record’. > If anyone wants to follow along, I’ve opened > https://github.com/weewx-mqtt/publish/issues/28 > rich > > On Wednesday, 8 July 2026 at 10:10:07 UTC-4 Greg Troxel wrote: > >> John Smith <[email protected]> writes: >> >> >> But, I do see a potential need to not publish as frequently for some >> MQTT >> >> clients >> > >> > Wouldn't that just be a case of checking what's being published has >> > changed? >> >> Perhaps, but it gets complicated. >> >> For me, with weewx to MQTT to Home Assistant (HA), there is a flow where >> each mqtt publish results in a state update in HA which results in a >> database record. Recording temperature every 15s, or whatever some >> rapid LOOP does, is excessive. I have settled on every minute for a lot >> of (non-weewx) temperature sensors (e.g. an Si7021 and an ESP8266 with >> esphome), as a compromise between often enough and filling up the >> database and making all operations slower. Probably 2 minutes would be >> better. >> >> I also have an ancient UPS (it was shiny in 1995 :-) that is polled >> every second or so over serial by ups-nut, and I wrote python to send >> MQTT from that. For many things, I want a value every minute or so, to >> watch trends in line voltage, power usage, temperature. But, I want >> immediate alerting on things like input voltage going to zero, and >> battery voltage dropping sharply. >> >> I wrote code to assess updates (vs the last transmitted values), and to >> trigger a transmission if it had been long enough (60s), or if any >> variable was different enough than the last report. The code is easy to >> write and the art is picking "different enough". Surely my thresholds >> are tuned to my UPS. >> >> I am sending a json dictionary with everything, rather than individual >> topics. That's better for MQTT, and it means all values are updated at >> once, but it does mean line voltage fluctuations result in updates of >> values that aren't changing. >> >> It would be nice to have MQTTPublish/etc. be able to do this, so that >> there are more rapid updates during heavy rain (every rain click feels >> like news), rapid temperature drops, gusts, while not sending updates >> all the time. >> >> It would also be nice to have "send MQTT every archive interval (5 >> minutes) and every minute there isn't an archive transmission based on >> LOOP, even if LOOP is more frequent, so I could keep my archive interval >> at 5m and have 1m updates. >> >> Of coures, one can also make a good case that sending over MQTT is cheap >> and that the receiver should have the filtering. One might be sending >> MQTT and using it in Belchertown, where a viewer wants updates, and in >> HA, where you want a reduced update frequency when that doesn't result >> in substantially wrong data*. But whether it's cheap depends on the >> network path, and it could be some not-fiber-optics, ham radio, LoRa, >> etc. >> >> *By not substantially wrong data, I mean that if you do linear >> interpolation between two recorded points, the data points you didn't >> record will be close to that interpolated line. >> >> -- > 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 visit > https://groups.google.com/d/msgid/weewx-user/2b3fed33-5043-426e-9ac0-6740f6ed71c4n%40googlegroups.com > <https://groups.google.com/d/msgid/weewx-user/2b3fed33-5043-426e-9ac0-6740f6ed71c4n%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 visit https://groups.google.com/d/msgid/weewx-user/CAGTinV6-xEZ-YTGpeWTw%3DrZnoPYntHXXq_vEbmBTDnhtm7f%2BpQ%40mail.gmail.com.
