Metering Musings

I've been intermittently trying to get our smart metering datafeed out to to a server for better logging, but I don't want to run a 300W PC to tell me my baseload in the house is 300+N W. There are several clamp meter / arduino designs thanks to the folks like OpenEnergyMonitor and Nanode, but things should be easier as there's a nice serial out already documented by ERDF (there's also the upcoming 'linky' interface but we're still on old-school)

How much does all this malarkey cost -- off the shelf there are USB opto interfaces, but they're about €50 each (erk) I originally purchased an arduino datalogger shield (€40 + an arduino) hoping to use it with a nanode, but I  didn't get ethernet sending working (even after the slight hardware mod) - possibly due to known issues with stash depletion

So - where do we go (cheaply) from here? a R-Pi gives me cheap hardware with more stable ethernet but I'd have to interface in the opto tty interface (gpio? usb?) as there's no onboard serial. Plan B is to use my bifferboard and use the console interface: small, yep. Low power, yep. Decent ethernet and OS (openwrt) - yes.

So, time to order some parts and get down to prototyping...

Aaaand we're back

Yay. I now have shiny broadband again thanks to <a href="http://www.k-net.fr/">k-net</a>. One difference between now and last time is that I also have an ipv6 prefix off them, so my home machines are accessible withoit needing port forwarding. Well, would be if I could get the RA working better on the router.

I have a linksys E3000, but that doesn't sipport ipv6 by default, so instead I have one of the TomatoUSB variants installed that does. I'd rather not use stateless config, but pre-assign IP addresses in advance so I can keep say kids machienes in a separate subnet. Overall - seems to work faiely well and the 'sam knows' box seems to have noticed too: