Unlock the Power of OBD2: The Best Car Diagnostics and Fuel Tracker with WiCAN & Home Assistant

For car enthusiasts and tech-savvy homeowners, integrating vehicle diagnostics into a smart home system offers unparalleled insights into car health and performance. Discover how WiCAN, combined with the versatility of Home Assistant, becomes the best OBD2 car diagnostics and fuel tracker solution, empowering you with real-time data and automation capabilities right at your fingertips.

Setting up WiCAN for OBD2 Diagnostics and Fuel Tracking in Home Assistant

Transform your Home Assistant into a powerful car monitoring dashboard by leveraging WiCAN’s ability to bridge your car’s CAN bus to your smart home ecosystem. This guide will walk you through the essential steps to get your system up and running.

Prerequisites

Before diving in, ensure you have the following set up within your Home Assistant environment:

1. Mosquitto Broker Add-on: MQTT (Message Queuing Telemetry Transport) is the communication protocol WiCAN uses to send data to Home Assistant. Install the Mosquitto Broker add-on from the Home Assistant add-on store. This acts as the central hub for message exchange.
2. Dedicated Home Assistant User Account for WiCAN: For security and organization, create a new, dedicated user account within Home Assistant specifically for WiCAN. Note down the username and password, as these credentials will be needed to configure WiCAN’s MQTT settings.
3. Node-RED Add-on: Node-RED is a flow-based programming tool that simplifies the creation of automations based on the data received from WiCAN. Install the Node-RED add-on from the Home Assistant add-on store.

WiCAN Configuration

Now, let’s configure WiCAN to connect to your home network and Home Assistant:

1. Connect to WiCAN Access Point: Power up your WiCAN device. It will broadcast a Wi-Fi network, typically named WiCAN_xxxxxxxxxxxx. Connect your computer or smartphone to this Wi-Fi network.
2. Access WiCAN Web Interface: Open a web browser and navigate to http://192.168.80.1/. This will open the WiCAN web configuration interface.
3. Set Mode to Ap+Station: In the WiCAN configuration, set the “Mode” to “Ap+Station”. This allows WiCAN to act as both an access point (for initial configuration) and a station (to connect to your home Wi-Fi).
4. Configure Wi-Fi Connection: Enter your home Wi-Fi network’s SSID (network name) and password in the provided fields. This will allow WiCAN to join your local network.
5. Enable and Configure MQTT: Enable the MQTT protocol within the WiCAN web interface. Enter the Home Assistant user credentials you created earlier (step 2 under Prerequisites). WiCAN will use these credentials to authenticate with the Mosquitto broker in Home Assistant.

Node-RED Flow Import and Configuration

To streamline the process of interpreting and utilizing the CAN bus data, import the example Node-RED flow provided by WiCAN:

1. Download Example Flow: Download the wican_example_flow.json file from the WiCAN GitHub repository or the developer’s provided link. Make sure to replace device_id within the JSON file with your specific WiCAN device ID.
2. Import Flow into Node-RED: Open the Node-RED add-on in Home Assistant. Import the edited wican_example_flow.json file into Node-RED.
3. Configure MQTT Broker in Node-RED: Double-click on the “subsection Node” within the imported flow. Edit the server settings to include the IP address of your MQTT broker (typically your Home Assistant IP address) and the Home Assistant user credentials you set up for WiCAN.
4. Deploy the Flow: Click the “Deploy” button in Node-RED to activate the flow. This will enable Node-RED to listen for and process messages from WiCAN.

WiCAN setup with Home Assistant for car diagnostics and fuel tracking

Creating MQTT Sensors in Home Assistant

Now, define sensors in Home Assistant to display the specific OBD2 data you want to monitor, such as fuel level and temperature:

1. Edit configuration.yaml: Access your Home Assistant configuration files and open configuration.yaml for editing.
2. Add MQTT Sensor Definitions: Add the following lines to your configuration.yaml file, modifying state_topic and value_template to match the specific CAN bus messages you want to track. Example configurations for ambient temperature and fuel level are provided below. Adapt these examples for other parameters based on your car’s CAN bus data.

mqtt:
  sensor:
    - name: "Ambient Temperature"
      state_topic: "CAR1/Amb_Temp"
      unit_of_measurement: "°C"
      value_template: "{{ value_json.amb_temp }}"
    - name: "Fuel Level"
      state_topic: "CAR1/Fuel_Level"
      unit_of_measurement: "%"
      value_template: "{{ value_json.fuel_level }}"

Final Steps

Complete the setup with these final actions:

1. Restart Home Assistant: Restart your Home Assistant instance to apply the changes made to configuration.yaml.
2. Add Entities to Dashboard: After Home Assistant restarts, go to your desired dashboard and add new “Entity” cards. Select the MQTT sensors you defined (e.g., “Ambient Temperature,” “Fuel Level”) to display them on your dashboard.

By following these steps, you’ve successfully integrated WiCAN with Home Assistant, creating a powerful and personalized best OBD2 car diagnostics and fuel tracker system. Monitor your car’s vital signs, track fuel consumption, and even create automations based on vehicle data, all within your smart home environment.