py-hpsu-monitor

A bridge between the Rotex HPSU CAN bus and MQTT-based monitoring systems.

Table of Contents

• Background
• Install
• Usage
• Contributing
• License

Background

This is intended to be deployed on a device that has a physical CAN connection to a Rotex HPSU heating system. It polls a configurable set of registers via the Elster-Kromschröder protocol and forwards the received values via MQTT. It has only been tested with the following models:

• Rotex HPSU compact 508

Please contribute experiences with this or other models in an issue.

Install

The application may be deployed from source or as a container. In both cases, make a copy of the default-config.toml file, change the settings to suit your deployment scenario, and specify the custom configuration file when starting the program.

From source

To deploy from source use poetry to install or build a wheel.

The program itself can started by specifying the run command. The recommended usage is via the systemd unit file described below. Usually only the --config-file option will have to be sepecified for it to use the correct mqtt settings:

Usage: py-hpsu-monitor run [OPTIONS]

Options:
  --can-interface TEXT            CAN bus interface to monitor  [default:
                                  can0]
  --config-file FILE
  --register-definition-file FILE
                                  [default: /home/py-hpsu-
                                  monitor/.local/lib/python3.9/site-packages/p
                                  y_hpsu_monitor/elster_protocol/register_defi
                                  nitions.toml]
  --log-frames
  --log-registers
  --help                          Show this message and exit.

The commandline arguments and configuration file allows for parameterization of various aspects:

• the CAN connection
• the MQTT connection
• the Elster protocol registers to poll

As a container

The included Dockerfile contains build instructions for an image based on Alpine Linux. The recommended way to build and deploy it is podman:

$ podman build --rm -t py-hpsu-monitor:latest .

With systemd and CAN interface can0

If your OS uses [systemd] as the supervisor you can use the included systemd unit to let it supervise the container for you:

• Copy etc/py-hpsu-monitor.service to ~/.config/systemd/user/py-hpsu-monitor.service and potentially adjust the path to the configuration file.

• Copy etc/socketcan@.service to /etc/systemd/system/socketcan@.service.

• Enable both units:

  sudo systemctl enable --now socketcan@can0.service
  systemctl --user enable --now py-hpsu-monitor.service
  

Without systemd

To manually start the container without any supervision, make sure the socketcan interface is up and run sometime like:

$ podman run \
  --detach \
  --cgroups=no-conmon \
  --network=host \
  --volume $(pwd)/my-config.toml:/home/py-hpsu-monitor/config.toml:ro \
  localhost/py-hpsu-monitor:latest --config-file config.toml

Contributing

I welcome requests, bug reports and PRs.

Small note: If editing the Readme, please conform to the standard-readme specification.

License

MIT