Running on Pi 3b, accessing DS18B20
First the goodness … wired up the sensor on breadboard, connected to powered down Pi, powered up and bingo - sensor detected and installed and visible on iPhone, iPad and web dashboard … excellent… BUT…
Presentation on iPad dashboard excellent! This was the first route by which I accessed the data (which I assume only exists in your servers and is accessed by the dashboard for presentation). It updates continuously and when I select the different intervals they all display. (NOTE - the “last day” display orders the data from most recent on left to oldest on right, which seems odd to me! All other charts are the other way around! )
Presentation on iPhone - “live” works fine, but all other choices of interval show “No data available for this period” - seems odd since I know it is there and can see it on my iPad!
Web dashboard - since I cant get it to show anything with Firefox I tried Msoft Edge. I have discovered that for “live” if you just wait it does appear in the end and settle to a reasonable graph scale. However, nothing displays for any of the other intervals, even though the data is there.!