Yes, the names look similar but there is a big difference between two “historical-data” sets which are used in PWS_Dashboard.
The reason: We have two different needs for historical data.
We want to make graphs of our weather-data. Those graphs should show todays values, a month, a year a.s.o.
The data used by graphs can not be “realtime” as it is often calculated with a low frequency by the data-provider.
We want to have the high-lows of our weather-data but those should be as “real-time” as possible.
But not all weather-“programs” upload those values so we have to calculate the missing high-low values ourselves.
Obvious, or sadly, we can not use the same set of data for both usages.
Graphs data solution 1: Weather Underground
If you set to use the WU data for graphs AND your station XXXXXXXX uploads to WU, the scripts will use that WU data (if the api-key is valid).
The data is cached in pwsWD/chartswudata/ and pwsWD/wudata/
All graphs will be available from the first day the station started uploading to WU (start-date has to be set in settings)
As older data can have errors, one can update/ remove errors in the local WU-data master copy in pwsWD/wudata/
==> use this script pwsWD/_wu_upd.php?pw=12345
IMHO it is unwise not to use WU, and it is free. You store your weather-data, retrieve it anytime you want, you get a nice weather-forecast and you can use extra interesting scripts to browse and inspect your weather-data.
Graphs data solution 2: Generate your own data
For those who choose NOT to use WU-graphs data
=> your graphs-data will be generated with a “cron-job” running every 5 minutes
The generated data is cached in pwsWD/chartsmydata/
Data is saved every 5 minutes cron-run for “today-values” and every 00:00 run for month / year values.
It are simple .txt files. Editing/removing errors is done with a text-editor.
Missing High-Low values solution
A small files is created / maintained by a “cron-job” running every 5 minutes
It will compare current high-lows and if needed it will update the today/month/year high-lows with the latest values
The file is located in pwsWD/_my_settings/history.txt
The live-data script uses that file plus the latest-measurements to calculates “realtime” high-lows to displayed in the blocks on your dashboard.
One can generate a “start-history” using the stations WU-data: => pwsWD/PWS_hist_recreate.php?pw=12345
One can always update the history file if it has an error-value in it: => pwsWD/PWS_hist_update.php?pw=12345
The cron-job every 5 minutes
That cron-job has some more tasks: Improve response times by pre-loading external data-files such as forecast, AQ-data a.s.o.
And it also takes care of the loading / assembling graphs-data and high-low data.
Where to get a cron-job?
1. Provider-cron-server normally use an archaic interface xyz/abc/php7.7 /home/user/whatever/pwsWD/PWS_cron_stationcron.php
Most errors occur in setting the correct path and carefully check if the same PHP version is used as your website is using.
Nearly all external solutions are better than using the cron-server from spme providers, who sometimes even charge extra for that “feature”.
2. External cron-servers use the wget/browser format such as “yourwebsite.com/pwsWD/PWS_cron_stationcron.php”
Free external cron-jobs at:
https://www.cronjob.de/ in German
Free cronjobs - from minutely to once a year. - cron-job.org (Kostenlose Cronjobs - von minütlich bis einmal im Jahr. - cron-job.org in German)
Multiple others also when using Google-search
3. Weather-Program-cron
Multiple weather-programs (WD, Meteobridge) are able to schedule a 5 min http request => which is identical to running a cron.
Read-me https://pwsdashboard.com/documentation2012/11_cron.pdf