Reads serial data from smart meter, and post it to MQTT topic
Copied from https://github.com/neographikal/P1-Meter-ESP8266-MQTT
use https://github.com/knolleary/pubsubclient
adjust MQTT_MAX_PACKET_SIZE to 512 in pubsubclient.h
I changed the softserial to hardware serial
Connector pinout. I used pin 2,3 and 5. On a 4 pin connector this is 1,2 and 4 offcourse ;-)
This schema will get you started:
I did not use the connector on the right, this is used for a oled screen. I did plan to use the LED, but it isn't implemented in code right now.
Result in MQTT lens:
Jumer needs to be connected for meters with open collector (Landis + Gyr 350, Iskra) and for meter who don't have that, leave open (Kamstrup, Kaifa).
T1 - BC547 R1, R2 - 1K ohm R3 - 2.2K ohm R4 - 470 ohm