As mentioned previously, I’ve built a home temperature monitoring system on top of the beer fridge controller that Doug and I built over Christmas. I later added a hygrometer and whole of house power measurement using a Current Cost. There is also a simple server which provides a UI for the system, which previously used PNG graphs generated from Google’s Chart Server API.
I was checking out Jon’s car hacking the other day, and was impressed by his flash graphs. However, as best as I could tell he’s using a commercial flash charting tool, whereas I wanted something open source. I dug around and found Open Flash Charts which was exactly what I wanted.
So, first off here is an example of a flash chart. This one is power usage at my house from Friday, compared with Wednesday:
Then all you need to do on the HTML side is include a div with the right id where you want the graph to go. For this post, that looks like this:
Then you just need to write the JSON which represents the graphs content. That’s well documented on the Open Flash Charts site, but you can find the JSON for my graph at http://www.stillhq.com/json/2010.04.23;2010.04.21/Watts if you want to see it.