How to monitor your Envoy router with MRTG
So I am into green, whole family is. This past summer, I decided to install solar panels. Got a 4.4KW system installed with Enphase microinverters.
Traditional solar panel system generate DC in the panels, and all of them goes to a battery bank, then a DC-AC converter for the house. It’s big, bulky and wasteful (converting DC-AC, etc). The Enphase microverters uses a DC-AC converter per panel. So no batteries needed, and losing one panel (whether shade, damage, whatever) is not going to stop power production.
Anyway, long story short, along with the microinverter come an Envoy, which is essentially a small embedded computer that talk with each inverter, query their status (power generation, heat, etc.), collects them and send them to a central place (Enphase’s server).
You have the option of subscribing to Enphase Enlighten program which allow you to login to a personalize website and view your power generation history with nice graphs, etc. The first few months are free after installation so you can play with it and see how it work.
I didn’t want to pay for something I can do myself. The microinverters talk with the Envoy over the power lines, so use their own protocol. But since I have access to the Envoy controller, I can query it for the data it collect from the inverters. There is a web interface on the unit that I can login to and see the data. But there is no programmatic way to get that data, e.g no snmp or API that I can use to ask the Envoy.
Hmmm, ok, I’ll screen scrape the web interface. So I wrote a little perl script to do just that, and that script output MRTG data for graphing locally.
Sorry, didn’t finish this yet. I’ll post my little perl script and the config I used for MRTG when I have chance.
I posted my MRTG config and perl script in the comment to this post. Too lazy to put it here….