Over the long weekend I think I will set up power monitoring of my smart meter to track power usage over the day.
What I will probably do is just use the 1000 imp / kWh light with a phototransistor to measure power usage using an esp-01 sending back via mqtt to openhab.
Before I do that though, has anyone successfully interfaced with the optical serial port on the meter? Mine is a EDMI MK7C meter that supposedly supports through the Optical port: FLAG (IEC 62056-21) or
ANSI Type 2 (ANSI C12.18) as well as the option for passive RS-232. I've had a quick look at https://tasmota.github.io/docs/Smart-Meter-Interface/ but, I'm not sure about using that. Also - sending data to it might show up on a report somewhere (local communication initiated), so, I'm less keen on actively communicating with it.
Looking at the optical port though my phones camera I can see the led flickering, so, I think it's currently sending something (passive 232?). Has anyone here looked into this?