02 HARDWARE - patience4711/ESP8266_read_p1meter GitHub Wiki

The hardware is very simple. just an esp8266 like wemos, nodemcu, etc, a 6-core wire with an RJ-11 jacket an a 10k resistor. If you want to make it nice you can use a piece of stripboard and a 4 core screw terminal. The wiring is explained in the picture below. We can pull up the rx port with a pin of the ESP. This triggers the output of a telegram by the meter, and also pulles-up the open collector rx-pin of the meter. This works oke, maybe it helps to prevent the contineous serial transmission of the meter (costs energy).

Since my meter is too far away from my router (no wifi connection) i had to use a 15m long 4 core telephone cable to position the ESP closer to the router. This works oke.

This wiring is suitable for a meter with a so called open collector output. This requires that the rx-pin is pulled up.

p1WIRING another suggestion using a long cable between. p1WIRING

After soldering on a little piece of stripboard.