Controller Area Network (CAN)

The can node-type allows the exchange of signals via a CAN bus.

Prerequisites

This node-type does not have any special library dependencies. It is always available.

Implementation

The source code of the node-type is available here: https://github.com/VILLASframework/node/blob/master/lib/nodes/can.cpp

Configuration

interface_name	string Name of the Socket CAN interface
	object (Input configuration (received by VILLASnode))
	object (Output configuration (sent out by VILLASnode))
vectorize	integer Default: 1 This setting allows to send multiple samples in a single message to the destination nodes. The value of this setting determines how many samples will be combined into one packet.
	Array of Hook Object (object) or Hook Name (string) (hook_list)
builtin	boolean (Builtin hook functions) Default: true By default, each node and paths has a couple of default hooks attached to them. With this setting the attachment of built-in hooks can be disabled.

{

• "interface_name": "string",
• "in": {

  • "signals": [

    • {

      • "can_id": 0,
      • "can_size": 8,
      • "can_offset": 0,
      • "name": "Bus123_U",
      • "unit": "V",
      • "type": "integer",
      • "init": 0,
      • "enabled": true

      }

    ],
  • "vectorize": 1,
  • "hooks": [

    • "print",
    • {

      • "type": "limit_rate",
      • "rate": 1000

      }

    ]

  },
• "out": {

  • "signals": [

    • {

      • "can_id": 0,
      • "can_size": 8,
      • "can_offset": 0,
      • "name": "Bus123_U",
      • "unit": "V",
      • "type": "integer",
      • "init": 0,
      • "enabled": true

      }

    ],
  • "vectorize": 0,
  • "hooks": [

    • "print",
    • {

      • "type": "limit_rate",
      • "rate": 1000

      }

    ]

  },
• "vectorize": 1,
• "hooks": [

  • "print",
  • {

    • "type": "limit_rate",
    • "rate": 1000

    }

  ],
• "builtin": true

}

Example

node/etc/examples/nodes/can.conf

nodes = {
    can_node1 = {
        type = "can"
        interface_name = "vcan0"
        sample_rate = 500000

        in = {
            signals = (
                {
                    name = "sigin1"
                    unit = "Volts"
                    type = "float"
                    enabled = true
                    can_id = 66
                    can_size = 4
                    can_offset = 0
                },
                {
                    name = "sigin2"
                    unit = "Volts"
                    type = "float"
                    enabled = true
                    can_id = 66
                    can_size = 4
                    can_offset = 4
                },
                {
                    name = "sigin3"
                    unit = "Volts"
                    type = "float"
                    enabled = true
                    can_id = 67
                    can_size = 8
                    can_offset = 0
                }
            )
        }

        out = {
            signals = (
                {
                    type = "float"
                    can_id = 66
                    can_size = 4
                    can_offset = 0
                },
                {
                    type = "float"
                    can_id = 66
                    can_size = 4
                    can_offset = 4
                },
                {
                    type = "float"
                    can_id = 67
                    can_size = 8
                    can_offset = 0
                }
            )
        }
    }
}