ESP8266 P1 to WiFi

Simple Arduino Sketch that can be used to stream P1 data (Dutch Smart Meter Requirements/DSMR) over WiFi using an ESP8266. Can be used to integrate a smart meter into Home Assistant without having to run a cable from your server to your smart meter.

⚠️ Works only with DSMR 5.0 smart meters, which supply 5V at 250 mA! The DSMR 4.0 specification requires the P1 port to supply 5V at 100 mA, which is insufficient. Your smart meter's DSMR version should be printed on the smart meter itself.

Requirements

Everything I've used is listed below, including a link to the product page at the store I bought them at.

Flashing the Firmware

Install the Arduino IDE with the ESP8266 Arduino Core (see documentation)
Clone this repository and open it in the Arduino IDE
Adjust the settings in the Sketch to your needs
You should at least adjust the SSID and PASSWORD settings so the ESP can connect to your network
⚠️ The ESP8266 can only connect to 2.4GHz networks
Use the USB Serial Port Adapter to flash the firmware (see Flashing Schema)
⚠️ Make sure you only supply 3.3V to your ESP8266
Connect all components (see Runtime Schema)
Plug it into your smart meter
Enable the DSMR integration in Home Assistant (see Home Assistant Configuration)

Flashing Schema

From	To
USB Serial Port Adapter VCC	ESP8266 3V3, ESP8266 EN
USB Serial Port Adapter GND	ESP8266 GND, ESP8266 IO0
USB Serial Port Adapter TX	ESP8266 RXD
USB Serial Port Adapter RX	ESP8266 TXD

Runtime Schema

From	To
P1 pin 1 (5V)	Voltage Regulator VIn, P1 pin 2 (RTS)
P1 pin 6 (GND)	Voltage Regulator GND, ESP8266 GND
P1 pin 5 (TX)	ESP8266 RX
Voltage Regulator VOut	ESP8266 3V3, ESP8266 EN

Home Assistant Configuration

Example configuration for the DSMR Slimme Meter integration below:

sensor:
  - platform: dsmr
    port: 1337
    host: 192.168.1.130
    dsmr_version: 5

Troubleshooting

The ESP8266's IO2 pin can be connected to your USB Serial Port Adapter's RX pin for debugging purposes.

Example Debug Output

* VERSION         2021.01.23+1
Network Settings:
* HOSTNAME        p1
* SSID            SomeSSID
* PASSWORD        REDACTED
* MAX_CLIENTS     4
* PORT            1337
Serial Settings:
* DEBUG_BAUD_RATE 9600
* P1_BAUD_RATE    115200
* P1_MODE         28
* P1_INVERT       1
General Settings:
BUFFER_SIZE       128
Starting WiFi connection
Waiting for WiFi connection...
Waiting for WiFi connection...
Waiting for WiFi connection...
Waiting for WiFi connection...
WiFi connected at 192.168.1.130
Starting server
Starting OTA server
Client 192.168.1.163 accepted

LouisMT/ESP8266-P1-to-WiFi