An ESP32 CanBus shield - made for hoval homevent, but for all canbus applications

Functionalities :

• Compatible with 1000 or 900 mil width ESP devkit
• Full headers for extending or debug
• The card use a ESP32-WROOM-32D as logics and wifi connection. (You can get a 32U if you want an external antenna)
• The software runs under esphome to be easy to customize and linked with https://www.home-assistant.io
• Power is taken from CanBus 12V and converted to 3.3v with AMS1117-3.3V (not needed but recommended, if cutting the "3v3V cutout", you can use external power supply)
• SN65HVD230 3.3-V CAN Bus Transceivers

Fabrication :

• PCB can be ordered with chips assembled at JLPCB for 50$ for 5 boards.
• ESP32-WROOM-32D costs approx 3.8$
• Box is 3D printed or fit in a 86x86 electrical box

Firmware

web interface at http://canbus.local/

Features

• Powered by ESPHome
• Webserver enabled at canbus.local
• Automatically recognized by Home Assistant

Installation

Requirements

Make sure you have Python and ESPHome installed.
To install ESPHome you can follow the manual installation guide or use Docker.

You can validate your installation by running

> esphome version
Version: 2023.11.6

Firmware configuration

Enter your Wifi SSID and password in secrets.yaml.
Then open config.yaml and make the following changes:

1. Set can_tx_pin and can_rx_pin
2. Update the device list. You can find the list of your hoval devices in your room control unit under maintenance. (e.g. HV(8) is written as TT_HV_addr: "8")
3. Select your desired presets. All presets are located at esphome/src/preset.
   e.g. to select the HV preset in French:

packages:
  # ...
  hv_sensors: !include src/preset/HV/sensors_fr.yaml
  hv_inputs: !include src/preset/HV/inputs_fr.yaml

If you want to create your own preset or need other datapoints have a look at esphome/hoval_data_processing

Flash the firmware

Connect your ESP32 via USB to your computer. (Only required for the first time, subsequent installations can be done over WiFi)
Then run esphome run config.yaml

Licence:

• Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC-BY-NC-SA)
• No commercial use