This post is about graphing the data
One of the things I identified early on in my design, was that I didn't want to be constrained to 'fixed' graphs.
Since my application was to allow non intrusive monitoring of the well-being of an individual/house, I needed to be able to mix and match what was on the screen, and zoom in if required.
The fixed graphs within OpenHAB were not going to be suitable for this.
I looked at exporting the data, but this posed its own problems.
- How often (Hourly, daily or several times per day, what times, etc)
- Where do I send it that maintains its security.
- What do I export.
As I pondered these I came across an add-on to OpenHAB called HABmin.
It compliments and adds some other features, but best of all it includes graphing using Highcharts which I'd spotted earlier.
I've already shown a few graphs, but having the ability to zoom at will is a real benefit for my application.
Hot Water graph showing the various rises
You simply click and slide the mouse across the area you want to zoom into and it refreshes.
You can continue zooming as far as you want, it doesn't seem to matter, as long as the data is there.
You can add other data sources and it will automatically adjust the range to suit (hence why I had to reduce the illumination graphs).
Once you update, you may need to zoom in again, but that's minor compared to the flexibility you get.
Once you have selected the sources for the graph, you can save and customise it.
In this one, I specified the colours, and the Max and Min setting, so it always stayed the same.
You can also specify the length of time (in this case 1 Hour), and once saved it simply pulls that data and assembles it for you.
The data is able to be zoomed, or shifted in time, while the colour and range you saved stays.... neat feature.
Once I have a more complete set of data (ie hasn't been changed, stopped and generally fiddled with), I can save a few graphs that will show the results consistently.
This one hasn't really ticked anything off my list, but it may help someone else at some point in time.
It has highlighted that the Hot Water temperature sketch needs adjusting.
Currently it will send if the temperature varies by 0.1 deg, and for this purpose that is too fine.
I really need to apply some logarithmic scaling, or incorporate time into the decision to send or not to send.
At the moment the RF isn't causing any issues, but it is consuming lots of RPi time.