Well, I think my MQTT enabled smart meter is rather smart too, but this one is smart also, but in somewhat different way…
A few weeks ago my ‘good old‘ Domotica buddy Pieter Knuvers started asking questions about my new smart meter, its P1 port and if I could build something for him to get the P1 datagrams into his system. (B)Wired, preferably via Ethernet. OK, that means that Pieter needed something completely different than what I made for myself – no Simplecortex needed, no MQTT publishing and stuff like that. A simple TTL to Ethernet server would do.
And then I remembered a wiki page where I’d seen just that. I looked it up and indeed this was all Pieter needed; so I bought the EZL70A, an enclosure and started building.
The EZL70A module is the biggest part and all that was needed was an additional signal inverter. For that I used a 7404 hex inverter, the same I used for my own smart meter, so I already knew that it would work. A few wires for power, signals and the hardest part was done.
I put some heat shrink around it and was ready to put all the components inside the enclosure.
And this is what it looked like after the first evening. Soldering a few wires, cutting some holes in the enclosure and Pieter’s smart meter would be Ethernet enabled, exactly what he wanted to have. As you can see the EZL70A, together with the signal inverter, fits nicely into a small enclosure of 100 x 50 x 25 mm.
As power cable we decided to use a USB cable; that seemed like a good idea since it’s not that strange anymore to find a USB socket in the meter cabinet – it’s the most common place to also find a NAS, router or Internet modem. And all of those devices have USB these days 🙂
After a brief test with my own smart meter I sent the P1 to Ethernet converter to Pieter. He had already finished the code for his own homebrew Domotica system to parse the P1 datagrams with the help of a logfile of my own smart meter.
So now all we had to do was waiting for the smart meter to be installed in his house. And last thursday it was; and Pieter connected the converter, changed the IP address and his smart meter was connected!
The accessibility of the P1 datagrams, the ease of building, the relatively low costs – it made us wonder why this wouldn’t work just as well for others as it did for Pieter… if we could just add some extra functionality to this (built-in web-page with charts etcetera) …
So we’ve both started doing some research… stay tuned!