teleinfo2mqtt-rs

Convert TeleInfo frames from a Linky meter's serial port to Home Assistant-compatible MQTT messages.

Overview

sequenceDiagram
    participant tic as Linky TIC
    participant pitinfo as PITInfo
    participant rpiz as Raspberry Pi Zero
    box green This project
    participant t2m as teleinfo2mqtt-rs
    end
    participant mqtt as MQTT Broker
    participant ha as Home Assistant
    tic->>pitinfo: IEC 62056-21 serial
    pitinfo->>rpiz: GPIO serial
    rpiz->>t2m: Linux serial port
    t2m->>mqtt: mqtt
    mqtt->>ha: mqtt integration

Reasoning

This is a rewrite of the fmartinou/teleinfo2mqtt that is written in Javascript.

This was only done for learning purposes, as the original project is working perfectly fine.

The only advantage of this project is that it is written in Rust, which means a single binary to deploy and very low resource usage, which is perfect for a low-power device like a Raspberry Pi Zero 2 W, which is what I use.

It uses less than 1% of CPU and 2-3 MB of RAM on my Raspberry Pi:

pi@raspberrypiz ~> ps -p $(pgrep teleinfo2mqtt-r) -o %cpu,%mem,rss
%CPU %MEM   RSS
 0.5  0.5  2560

Caveats

• Only supports "historical" Linky mode, not "standard" mode, because my Linky is in historical mode.
• MQTT discovery for Home Assistant is not implemented

Usage

The following environment variables are required:

• MQTT_HOST: the MQTT broker to connect to, e.g. 192.168.1.42
• MQTT_USERNAME: the MQTT broker username
• MQTT_PASSWORD: the MQTT broker password

The following environment variables are optional:

• SERIAL_PORT: the serial port to read from, defaults to /dev/ttyS0
• MQTT_PORT: the MQTT broker port to connect to, defaults to 1883

The binary can then be run with:

./teleinfo2mqtt-rs

My setup

My setup is as follows:

• Linky meter manufactured by Itron, historical mode
• PiTInfo shield to get the serial data from the TIC module through the GPIO pins
• Raspberry Pi Zero 2 W to run the binary
• Mosquitto as the MQTT broker to receive the MQTT messages, running as an addon in Home Assistant
• Home Assistant to integrate the MQTT messages

Home Assistant integration

Development

The usual Rust commands apply:

cargo build
cargo run

Architecture

The project is architected around Streams from futures.

---
title: Data flow
---
graph TD
    subgraph Main flow
        buffer[Serial buffer] -->|Reader| A
        A[SerialPort ASCII] -->|Stream| B[Teleinfo raw frame]
        B -->|Stream| C[TeleinfoFrame struct]
        C -->|Stream| task
        subgraph task[Tokio async task]
            D[MQTT publisher] -->|MQTT| E[MQTT broker]
        end
    end

    subgraph Tokio async task
    Z[MQTT even loop] -->Z
    end

Cross-compilation

Unfortunately, I couldn't get cross-compilation to work from macOS aarch64-apple-darwin to aarch64-unknown-linux-gnu because of the libudev-dev dependency on Linux.

A VS Code Dev Container is provided to have a working rust-analyzer and clippy in VSCode on macOS and to be able to compile the project on Linux.

TeleInfo specs

PDF from Enedis can be found under docs/Enedis-NOI-CPT_54E.pdf.

The important stuff is for historical mode is:

Physical layer

• The baud rate is 1200 bauds
• 7 data bits are used to represent each ASCII character

The teleinfo data can be read from the serial port using picocom:

sudo picocom -b 1200 -d 7 /dev/ttyS0

Data link layer

The TIC sends frames continuously. Each frame is separated by a delay of 16.7 ms < t < 33.4 ms.

• Each frame is composed of multiple data sets
• Each data set is composed of a label, a value and a checksum
• Each frame starts with "Start TeXt" STX (0x02) and ends with "End TeXt" ETX (0x03)

STX<data set><data set>...<data set>ETX

A data set is composed of:

\n<Label>\t<Value>\t<Checksum>\r

The checksum is (S1 & 0x3F) + 0x20, considering S1 the sum of the ASCII values from the label (included) to the checksum (excluded)

A full frame on my Linky meter looks like this:

0x02
ADCO 012345678912 B
OPTARIF BASE 0
ISOUSC 30 9
BASE 002815235 %
PTEC TH.. $
IINST 001 X
IMAX 090 H
PAPP 00260 )
HHPHC A ,
MOTDETAT 000000 B0x03

Application layer

In the code, the frame is represented as:

pub struct TeleinfoFrame {
    pub adco: String,     // Adresse du compteur
    pub optarif: String,  // Option tarifaire
    pub isousc: String,   // Intensité souscrite, en A
    pub base: String,     // Index option base, en Wh
    pub ptec: String,     // Période tarifaire en cours
    pub iinst: String,    // Intensité instantanée, en A
    pub imax: String,     // Intensité maximale appelée, en A
    pub papp: String,     // Puissance apparente, en VA (arrondie à la dizaine la plus proche)
    pub hhphc: String,    // Horaire Heures Pleines Heures Creuses
    pub motdetat: String, // Mot d'état du compteur
}