Socket Stage (CAN)

This stage allows you to receive CAN packets from a CANbus via the Linux SocketCAN interface. Packets will be grouped together into CanPacketGroup messages before publishing.

Grouping is intended as a mechanism to batch messages on high-rate sensors, reducing performance overhead of publishing and logging individual CAN packets. If your data rates are low, just leave the group_size parameter set to one (or zero for the default).

Configuration

Basic configuration is in the SocketCanStageConfig:

device_name - Device name to connect to (ie, vcan0)
group_size - The number of packets to bundle before publishing a group.
thread_priority - Priority to set the for the reading thread.
data_receive_timeout_ms - Reconnects if data hasn’t been received in this interval.

Interacting

All packet groups are published under packet_group in the stage’s namespace.

The stage listens for data to publish on the egress_packets channel. Anything received will be written over the CANbus when connected (or dropped otherwise). Packets are written 1:1.

Notice

CAN-FD is not currently supported by this interface.

Metrics

The stage periodically (at 1Hz) emits a SocketStats structure containing rate and size information. This is published under the socket_stats channel within the stage’s namespace.