Code is AS-IS without any warranty of any kind...
Hardware used :
- Nodemcu 1.0 (but any ESP8266 breakout with enough pins should do)
- Optocoupler SFH620A (but LTV-814 could be even better)
- 2N7000 or BS170
- 2 * 10k + 1 * 4.7 resistors
- Version "Historique" (i.e. compatible with older meters) only for the moment
- Version "Standard" (a.k.a new Linky version) to be written
The python OTA helper can be used to upgrade the software on the ESP8266
Corresponding blog entry: http://www.guillier.org/blog/2017/xxxxxxx