Boiler Logger for Remeha Tzerra

Features

This logger is meant to read data from a Remeha Boiler and distribute it to different backends. Currently it only supports reading from a Remeha Tzerra and writing to a MQTT broker, a CSV file, and/or MySQL/MariaDB. It should be easy to add support for other Remeha Boilers.

There is an additional Python Script (plotlytest.py) which can read the csv file written by the logger and render some nice diagrams. As the name suggests it uses Plotly to do interactive diagrams and dash to distribute it with a simple webservice.

Installing

You need Python 3 installed. There is a setup.py provided, which you could call directly or even better use "pip" to install:

For the latest released version:

pip install remeha-tz

or for the latest version on github:

pip install git+https://github.com/TheRikke/remeha_tz.git@master

If you want to log to a mysql/mariadb, please copy config/remeha.conf to ~/remeha.conf, ~/.remeha.conf or /etc/remeha/remeha.conf and change the database parameter in there.

If you don't need the plotly diagrams, You can remove the 'dash' and 'plotly' dependencies from setup.py.

Config

The tool reads the config from '/etc/remeha/remeha.conf', ~/.remeha.conf or a config specified in the environment variable REMEHA_CONF. For an example see config/remeha.conf

{
  "database_logger": {
    "enabled": false,
    "host": "testserver.local",
    "user_name": "database_user",
    "password": "secret_passwort"
  },
  "mqtt_logger": {
    "enabled": true,
    "host": "localhost",
    "port": 1883,
    "tls_enabled": false,
    "comment-topic": "specify the topic every value will be published to.",
    "topic": "boiler/",
    "log_values": ["outside_temp", "flow_temp", "return_temp", "calorifier_temp", "airflow_actual"],
    "log_values_with_timestamp": [ "status", "substatus", "locking", "blocking", "airflow_actual"],
    "Comment-Log_values_with_duration": "Log how long a specific value has been active. Useful to log something like 'How long did the boiler burn to heat the domestic hot water supply'",
    "log_values_with_duration": [
      {
        "value_name": "status",
        "expected_value": "burning_dhw"
      }
    ],
    "scale_to_percent": [
      {
        "value_name": "airflow_actual",
        "lower_limit": 0,
        "upper_limit": 2900
      }
    ]
  }
}

Usage

remeha.py -d /dev/ttyUSB0 --output test.csv

This will start logging to the local mqtt broker with the topic 'boiler/' and the specified csv file. See --help for more options and config/remeha.conf for the values logged per default.

Other useful information

The csv file contains the raw frame received from the boiler and not the decoded values. This is done because I'm not sure about the meaning of some values. By saving the raw frame we don't lose any data and are able to decode them later. Also it makes supporting other boiler types more easy.

To convert the csv with raw values to csv with readable values use the convert script:

remeha_convert.py --input-file test.csv > converted.csv

Hardware

Most Remeha boiler use a simple serial connection with 5V TTL. If you have a Raspberry Pi, Arduino or similar, it can most likely be directly connected to the boiler. To connect it to 3.3V like a PC you need a TTL converter or a TTL-USB converter. The remeha tzerra uses a RJ10 aka. 4P4C connector. I've used an old phone cord to connect my Raspberry Pi clone to the boiler.

https://en.wikipedia.org/wiki/Modular_connector#4P4C

Connect the number pins of the 4P4C connector to the following pins of your board or TTL-USB converter:

• pin 1 - GND
• pin 2 - TX
• pin 3 - RX
• pin 4 - VCC 5 (I did not connect this one. Just for reference.)