Collect data from the CAN bus using the Elster protocol

• Requirements
• Installation
  • Cron Job
  • Database (optional)
  • Grafana (optional)
• Config
  • CAN bus
    • Example
    • Description
  • Data
    • Example
    • Description
  • Datasinks
    • Configuration File
    • Storing Data to MySQL
    • Sending Data to an HTTP Endpoint
    • Output to the Console
• Resources
• License

• Python 3.9
• MySQL (optional)
• Grafana (optional)
• Raspberry Pi + CANable (or similar devices)

• Download the latest version

  wget https://github.com/fknipp/canpicker/archive/refs/heads/main.zip

• Unzip the package

  unzip canpicker-main.zip

• Change the directory

  cd canpicker-main

• Install the dependencies

  pipenv install

To collect the data every x minutes, it's necessary to create a cron job. This is an example to query the data every two minutes:

*/2 * * * * /home/pi/canpicker-main/bin/canpicker

Execute the seed file via MySQL command line or copy the query into your MySQL shell.

With Grafana you can create your own dashboard with widgets or use the existing template.

The configuration for the CAN bus and for the data to be queried is located in config.yml. The database configuration is located in .env.

File: config.yml

can:
  interface: can0
  sender: 680

• interface: CAN bus interface
  • can0
• sender: Sender ID
  • 680

File: config.yml

See http://juerg5524.ch/data/ElsterTable.inc for the indexes.

data:
  - name: AUSSENTEMPERATUR
    index: 180.000c
    format: dec_val
  - name: QUELLENTEMPERATUR
    index: 180.01d4
    format: dec_val
  - name: FEHLER
    index: 180.0001

• name: Name for the data point
  • AUSSENTEMPERATUR
• index: Receiver and Register separated by a dot
  • 180.000c
• format (optional):
  • dec_val
  • mil_val
  • little_endian

File: .env

Rename the .env.example file to .env and adapt it for your needs. Otherwise create it with the content for your usecase.

Tha values are stored in the table sepicker. See the seed file for the data definition.

DB_DATABASE=heat-pump
DB_HOST=127.0.0.1
DB_USER=root
DB_PASSWORD=

The data is sent as GET request to a configurable URL.

The URL template allows the substitutions:

• $timestamp for the timestamp in the ISO format
• $name for the name as configured in config.yml
• $value for the value retrieved on the CAN bus

HTTP_URL_TEMPLATE=http://loxone.local/dev/sps/io/$name/$value
HTTP_USERNAME=
HTTP_PASSWORD=

This is helpful for debugging.

CONSOLE_OUT=1

• http://juerg5524.ch/list_data.php
• https://github.com/andig/goelster
• https://github.com/Andy2003/heat-pump-api
• https://github.com/danielbayerlein/sepicker
• Integration with Loxone: https://github.com/fknipp/python-can-loxone-heating-integration

© 2020-present Daniel Bayerlein
© 2023-present Franz Knipp

See LICENSE for details.