would be great, if home asssistant will support sml protocol in the future. currently it is only supporting dutch dsmr protocoll.
home assistant dsmr sensor:
openhab supports both protocolls:
- https://github.com/openhab/openhab1-addons/wiki/dsmr-binding
- https://github.com/openhab/openhab1-addons/wiki/IEC-62056---21-Meter-Binding
als an alternative you could use volkszaehler (https://www.volkszaehler.org/) - it comes with own database and some basic chartings. I Integrated it into my homeassistant reading the json from an url: