This is my working configuration to poll a http://www.chinaenergymeter.com/1-1-15-dds238-2-zn-s-single-phase-din-rail-type-watt-hour-meter.html (I have the 65A hard wired variant - I've seen postings that the CT clamp version may not be as responsive
I'm using a wemos D1 mini (ESP8266) with a RS485 toTTL module (that's OK at 3.3v). This seems fine using software serial on D1/D2 at a polling rate of every 5s
- If the wemos stays connected to home assistant but CAN'T talk to the meter, HA will re-use the last value rather than marking it offline/NaN/unavailable