Messenger API

CanMessenger::Messenger is the high-level runtime API.

Constructor

CanMessenger::Messenger.new(
  interface_name:,
  logger: nil,
  endianness: :native,
  can_fd: false,
  adapter: CanMessenger::Adapter::Socketcan
)

Parameters:

• interface_name (required): CAN interface name such as can0 or vcan0.
• logger: Defaults to Logger.new($stdout) when omitted.
• endianness: :native, :little, or :big for CAN ID byte order.
• can_fd: Default CAN FD behavior.
• adapter: Adapter class or instance implementing the base adapter contract.

send_can_message

send_can_message(id:, data:, extended_id: false, can_fd: nil)

Behavior:

• Raises ArgumentError when required inputs are missing or invalid.
• Uses messenger-level can_fd when can_fd: is omitted.
• For non-argument runtime errors, logs and returns without raising.

send_dbc_message

send_dbc_message(message_name:, signals:, dbc:, extended_id: false, can_fd: nil)

Behavior:

• Requires a non-nil dbc instance.
• Calls dbc.encode_can(...) and then sends the encoded frame.
• Automatically sends DBC messages with the extended CAN flag when the DBC message ID includes the EFF bit.

start_listening

start_listening(filter: nil, can_fd: nil, dbc: nil) { |message| ... }

Behavior:

• Requires a block. If no block is provided, logs an error and returns.
• Validates filter: before opening the socket.
• Loops until stop_listening is called.
• Optional filter accepts:
  • Integer
  • Range<Integer>
  • Array<Integer>
• Unsupported filter values raise ArgumentError.
• Message payload shape from SocketCAN adapter:

{
  id: Integer,
  data: Array<Integer>,
  extended: true | false,
  decoded: { name: String, signals: Hash }, # only when dbc decode succeeds
  decode_error: { class: String, message: String } # only when dbc decode raises
}

When dbc: is provided, extended received frames are mapped back to the DBC message ID form before decode. If DBC decoding fails, the raw frame is still yielded with decode_error attached.

stop_listening

stop_listening

Sets the internal listening flag to false so the loop exits cleanly.