About

This project provides a simple library for reading data from a smart meter using its P1 port. It is written to be used with a P1 cable that transmits the P1 telegrams as a serial message over USB.

Those messages are then converted into a structured object and emitted as an event.

Getting started

Installation

Install the library using npm:

npm install p1-monitor

Now we can create a new P1Monitor instance by calling the factory function:

import { createP1Monitor } from 'p1-monitor';

const monitor = createP1Monitor({
    timezone: 'Europe/Amsterdam',
    path: '/dev/ttyUSB0',
    baudRate: 115200,
});

Before we start receiving events, we need to call the start method on the monitor:

monitor.start();

Configuration

The telegram parser can be configured to work with different kinds of smart meters. The default configuration adheres to the DSMR 5.0 specification, and can be changed by passing additional options to createP1Monitor().

Required options

type options = {
    /**
     *  The IANA timezone identifier, configured in your Smart Meter, that will
     *  be used when parsing the timestamps of the P1 messages.
     *
     *  Eg: "Europe/Amsterdam" or "America/New_York"
     */
    timezone: string;

    /**
     * The path to where the P1 cable is mounted.
     */
    port: string;

    /**
     * The baud rate to use when reading from the serial port. Most P1 cables
     * use 115200.
     */
    baudRate: number;
};

Additional options

type options = {
    /**
     * Whether to return a value with their unit, if specified.
     *
     * Defaults to: false.
     */
    withUnits?: boolean;

    /**
     * Whether the date values are returned as a Luxon DateTime,
     * or as the default JS Date object.
     *
     * Defaults to: false.
     */
    asLuxon?: boolean;

    /**
     * A timeout, in milliseconds, after which the last message is received, to
     * consider the serial port connection closed.
     *
     * Defaults to: 11 seconds.
     */
    timeout?: number;

    packet?: {
        /**
         * The character that denotes the start of the data in a P1 message.
         *
         * Defaults to: `/`
         */
        startChar?: string;
        /**
         * The character that denotes the end of the data in a P1 message.
         *
         * Defaults to: `!`
         */
        stopChar?: string;
    };
};

Usage

The P1Monitor will emit the following events:

• connected: Emitted when the first message is received by the P1 monitor.
• data: Emitted when a new message is received on the serial port.
• error: Emitted when an error occurs.
• close: Emitted when the serial port connection was closed.

Now, we can start listening to our monitor:

import { P1Packet } from './P1Packet';

monitor.on('data', (packet: P1Packet) => {
    console.log(packet);
});

The data event is emitted with a P1Packet object, which will look something like:

{
    "vendor_id": "Ene",
    "model_id": "XS210 ESMR 5.0",
    "version": "50",
    "transmitted_at": "2024-01-06T10:19:56.000Z",
    "electricity": {
        "equipment_id": "E1234567891234567",
        "tariff": 1,
        "received": {
            "tariff1": 2601.66, // kWh
            "tariff2": 2960.167, // KWh
            "active": 0.279 // kW
        },
        "delivered": {...},
        "active": {...},
        "failures": {...},
        "sags": {...},
        "swells": {...}
    },
    "gas": {
        "equipment_id": "G1234567891234567",
        "measured_at": "2024-01-06T10:15:00.000Z",
        "received": 5472.258 // m3
    }
}