• peripheral: Hardware identifier (e.g., CAN1, CAN2, CAN3).
• accept_all_messages: Boolean. If true, disables hardware filter optimization (promiscuous mode).
• is_extended_id: Boolean. Set at the bus level. Mixed-ID buses are not supported; all messages on a bus will share this framing.
• host_fault_library: Boolean. If true, indicates this bus is the primary uplink for fault communication (usually VCAN).

Node Attributes

• node_name: Name of the node. Must be unique.
• faults: (Optional) Array of fault definitions specific to this node.

CAN Message Attributes (TX)

• msg_name: Unique identifier.
• msg_desc: Short description of message purpose.
• msg_priority: [0-5]. See priority convention below.
• msg_period: Transmission frequency in ms.
• msg_id_override: Optional. Manual ID (supports hex 0x...). Overrides automatic linking. Must respect the bus framing limits.

RX Message Attributes

• msg_name: Name of the message to receive (must exist on the bus).
• callback: Boolean. If true, generates a weak-linked callback function in the driver.
• irq: Boolean. If true, processes the message in the RX interrupt context.

Signal Attributes

• sig_name: Signal name. Must be unique within the message.
• sig_desc: (Optional) Short description of signal purpose.
• type: C-type (uint8_t...double) or a custom type defined in common_types.json.
• length: (Optional for standard types) Bit-length. Required for custom packing or sub-byte types.
• unit: (Optional) Physical unit label for DBC generation (e.g., V, Amps, C).
• scale: Multiplier for physical value conversion. Default 1.0.
• min_val: (Optional) Minimum theoretical value.
• max_val: (Optional) Maximum theoretical value.
• choices: (Optional) List of strings for enum-like labels in DBC.

Remarks

Scaling Constants: The library generates static constexpr float constants for every signal with a scale != 1.0. format: PACK_COEFF_<MSG>_<SIG> and UNPACK_COEFF_<MSG>_<SIG>. Use these to avoid magic numbers in your application code.

Message Priority

Lower = higher priority. Range: [0-5]. PER vehicle convention:

1. event based, safety-critical
   • fault events, charge commands
2. periodic safety-critical vehicle operation
   • Motor commands, fault sync, charging
3. periodic torque path relevant
   • throttle, torque vectoring commands, steering angle
4. non torque path vehicle operation
   • cooling commands, daq log enable
5. Low frequency (<5HZ) periodic telemetry
   • battery voltage
6. High frequency (>5HZ) "best effort" telemetry
   • IMU raw data, shock pots, battery current

Fault Configuration

Node-specific faults are defined directly in the node JSON under the "faults" key. The library automatically generates bitfield-sync and event messages for fault communication based on these definitions.

Node Level

• generate_fault_messages: Boolean. If true, generates LCD string arrays for the node (usually only true for nodes with displays like the Dashboard).

Fault Attributes

• fault_name: Unique name within the node.
• min: Minimum healthy value. Triggers fault if value < min.
• max: Maximum healthy value. Triggers fault if value >= max.
• priority: Impact of the fault (warning, error, fatal).
• time_to_latch: Time in ms the condition must persist before the fault is latched.
• time_to_unlatch: Time in ms the condition must be healthy before the fault is cleared.
• lcd_message: String text for display on the dashboard or log.