This project provides SolarNode plugin that can collect arbitrary data from CAN bus networks. This is an advanced plugin that requires specific low-level knowledge of the CAN network you want to collect data from. It also requires a plugin that provides a CAN Bus Connection component to use, for example the SolarNode CAN Bus Connection plugin.

The plugin can be installed via the Plugins page on your SolarNode. It appears under the Datum category as CAN Bus Datum Source.

Once installed, a new CAN Bus Device component will appear on the Settings page on your SolarNode. Click on the Manage button to configure components. You'll need to add one configuration for each datum stream (source ID) you want to collect data on.

To understand how to configure this plugin, it is helpful to consider how CAN bus messages are structured. Each message contains a unique address and some number of bytes as content. CAN does not specify the format of any message, so some mapping information must be provided to decode a message from a given address. A message then might contain several pieces of information bundled together. The goal of this plugin is to capture CAN bus messages, decode the messages into individual property values, and map those values into datum properties.

The configuration for a given CAN Bus Device in SolarNode is broken into these parts:

You can visualize this structure like a tree. For example, here's a single Device with 2 messages and 5 properties:

TR-BUS-TEST1-MOT-1      # Device - a source ID
├── 0x0C03A1A7          # Message - a CAN bus address
│   ├── speed           # Property - part 1 of message
│   └── torque          # Property - part 2 of message
└── 0x1818D0F3
    ├── current
    ├── soc
    └── voltage

With that configuration, SolarNode might capture a datum that looks like this:

{
  "sourceId" : "TR-BUS-TEST1-MOT-1",
  "speed" : 1115,
  "torque" : 29426,
  "current": 8.1,
  "soc": 0.868,
  "voltage": 669.2
}

This plugin does not request values from the configured CAN bus. Instead, it listens for CAN messages from the CAN addresses configured, and captures the property values whenever a message arrives. When it needs to generate a datum object, it copies the appropriate properties that have been most-recently captured to a new datum instance and returns that. Thus the values on a given datum could have been generated at any point before the datum is generated. For most cases the messages on a CAN bus are emitted quite frequently, and the end result is that the property values captured in a given datum are reasonably close to whatever those property values might have been at the time the datum is generated.

It is also possible for datum to be generated that do not contain values for all the properties configured to be captured by that datum, if no message has arrived for a particular property. Again, this is not much of an issue because CAN messages are typically generated very frequently.

This plugin also provides a CAN Bus Device Configurer component will appear on the main settings page. This component lets you upload a KCD XML configuration file to configure all CAN Bus Device components, without having to use the settings form.

Each device configuration contains the following overall settings:

Each message configuration contains the following overall settings:

Each property configuration contains the following overall settings:

Value labels allow you to configure descriptive labels with specific property values. When configured, SolarNode will generate an extra status datum property named like Property with Label appended. For example, here are two value labels configured for values 0 and 1 with labels Normal and Broken, respectively:

Assuming the associated Property setting is configured as state, then when the captured property value matches 1 a stateLabel property would also be populated with a value Broken:

{
  "state"      : 1,
  "stateLabel" : "Broken"
}

This plugin will publish metadata based on the configuration provided. This is to help with client applications that want to understand the units used by each property. An example of the metadata is:

Each property will have the following metadata elements published:

Each property configuration contains the following overall settings:

{
  "created": "2019-12-15 20:50:06.480Z",
  "updated": "2019-12-16 01:01:54.518Z",
  "nodeId": 123,
  "sourceId": "/TR/BUS/TEST1/BAT/1",
  "pm": {
    "soc": {
      "name": {
        "en": "Battery State of Charge"
      },
      "unit": "",
      "sourceUnit": "%"
    },
    "current": {
      "name": {
        "en": "Battery Current"
      },
      "unit": "A"
    },
    "voltage": {
      "name": {
        "en": "Battery Voltage"
      },
      "unit": "V"
    },
    "regenEnergy": {
      "name": {
        "en": "Battery Input Energy",
        "fr": "Énergie d'entrée de la batterie"
      },
      "unit": "W.h",
      "sourceUnit": "kW.h"
    },
    "outputEnergy": {
      "name": {
        "en": "Battery Output Energy",
        "fr": "Énergie de sortie de la batterie"
      },
      "unit": "W.h",
      "sourceUnit": "kW.h"
    },
    "minCellVoltage": {
      "unit": "V"
    },
    "posIsoResistance": {
      "unit": "Ω",
      "sourceUnit": "kOhm"
    }
  }
}

Since version 1.4 properties can be defined using expressions. Expressions allow you to configure datum properties that are dynamically calculated from other properties or raw Canbus signal values.

Each expression configuration contains the following settings:

The root object is a ExpressionRoot object, which has the following properties: