Standardized framework for CAN communication and system-wide fault management within PER vehicles.

canpiler/: Jinja2-based Python module for parsing configurations and generating code
configs/: "Source of Truth" definitions for nodes, buses, and system-wide faults.
generated/: Auto-generated C files and headers for CAN nodes.
dbc/: CAN database (DBC) files for external analysis tools.
schema/: JSON schemas for validating configuration files.

Core Files:

can_common.h / .c: Shared hardware abstraction and logic.
faults_common.h / .c: System-wide fault management.
can_library.cmake: CMake integration and node library generation.

Usage

Define your CAN network and global faults in common/can_library/configs/ using the provided JSON schemas.
1. Use FDCAN peripherals on G4 and CAN peripherals on F4/F7.
Add to COMMON_LIBRARIES of your target: can_node_<node_name>.
Define your RX interrupt handlers to call CAN_handle_irq(CAN_TypeDef *bus, uint8_t fifo)

Note: Weird quirk: we run the CANpiler twice. Once during CMake configuration time and one during build time. This avoids any possibility of building with stale generated files.

Fault System

The faults_common module implements the FIDR (Fault Isolation, Detection, and Recovery) system. It manages the lifecycle of system-wide faults using a robust Finite State Machine (FSM) to prevent flickering and ensure deterministic fault handling.

Fault FSM Diagram

Usage:

update_fault(fault_index, value): Called by the owner node to feed sensor/status data into the FSM.
fault_library_periodic(): Tally active faults and broadcast a tx_fault_sync message.
is_latched(fault_index): Check if a specific fault is active.

Note: Each node is assigned a specific range of faults (MY_FAULT_START to MY_FAULT_END). Only the "owner" node can update the state of these faults, ensuring a single source of truth.