kaifa-meter

Introduction

This is a Python package that reads and decodes serial data from the HAN port of a few Kaifa electricity meters. It may be used as a Python library or as a standalone CLI.

Serial data frame decoding is fairly naive and based on inspiration from roarfred and Per Erik Nordbø. It uses the Construct library to parse messages in a simple and straight-forward manner that is easily understood and maintainable.

The CLI writes decoded data to either:

• Terminal (pretty-printed)
• File (pretty-printed)
• PostgreSQL database

Feedback and improvement suggestions are welcome.

Tested and supported meters

• MA105H2E

Untested meters (but should work)

• MA304H3E
• MA304H4
• MA304T4
• MA304T4

Installation

This package requires Python 3.6+. It depends on several third party packages, so I recommend installing it in a virtualenv. It is packaged to be installed through pip from GitHub.

$ pip install git+https://github.com/endrebjorsvik/kaifa-meter.git

Usage

Connect the electricity meter to a computer using a M-Bus-to-USB converter. It shall appear as a serial port (e.g. /dev/ttyUSB0 or COM3). To print decoded data to your terminal, run

$ kaifa_meter serial /dev/ttyUSB0

To save decoded data to file, run

$ kaifa_meter serial /dev/ttyUSB0 -o /path/to/outfile.txt

It is also possible to dump all data to a PostgreSQL database. To test the database setup, run

$ kaifa_meter initdb --dbname=<name of database> --dbuser=<name of database user> --dbtable=<table to create in database>

You can then dump data directly to the database by

$ kaifa_meter serial /dev/ttyUSB0 --dbname=db --dbuser=user --dbtable=table

Tested platforms

• Linux

Hardware

The package is tested on a Kaifa MA105H2E meter that is connected to a computer through the following cabling:

• M-Bus-to-TTL/UART using TI TSS721A. Assembled PCBs are available from AliExpress.
• PL2303 TTL/UART-to-USB converter. Higher quality TTL converters from FTDI should also work.