Hacker News new | ask | show | jobs
by mjochim 166 days ago
Electric meters often blink a signal LED for every X kWh, so other devices can read the signal. I'm not sure if this is used for bidirectional communications, though.
2 comments
bigfatkitten 166 days ago
No, but they also have a separate infrared interface for this.

https://en.wikipedia.org/wiki/IEC_62056

link
NegativeLatency 166 days ago
Smart meters have a whole protocol
link