can-isotp

import can import isotp import time import os # Configure CAN bus (uses 'virtual' bus by default for easy testing) # For a real setup, replace 'virtual' with your bus type (e.g., 'socketcan', 'peak') # and 'vcan0' with your channel. For Linux virtual CAN, ensure 'vcan0' is up: # Example: sudo modprobe vcan; sudo ip link add dev vcan0 type vcan; sudo ip link set up vcan0 bus_type = os.environ.get('CAN_BUSTYPE', 'virtual') can_channel = os.environ.get('CAN_CHANNEL', 'vcan0') # Attempt to open the specified CAN bus. Fallback to a mock bus for script execution. try: bus = can.Bus(channel=can_channel, bustype=bus_type) print(f"CAN bus opened successfully: {can_channel} ({bus_type})") except Exception as e: print(f"Could not open CAN bus '{can_channel}' with type '{bus_type}'. Error: {e}") print("Falling back to a mock virtual bus for demonstration purposes.") bus = can.interface.Bus(bustype='virtual', channel='vcan0', is_extended_id=False) # Define ISO-TP addressing parameters for a physical communication # rxid: The CAN ID this ISO-TP stack expects to receive (from ECU). # txid: The CAN ID this ISO-TP stack will send (to ECU). addr = isotp.Address( isotp.TargetAddressType.N_PHYSICAL, rxid=0x7E8, txid=0x7E0 ) # Create an ISO-TP stack using the high-level CanStack interface stack = isotp.stack.CanStack(bus=bus, address=addr) # Send an ISO-TP message (e.g., a diagnostic service request) payload_to_send = b'\x22\xF1\x90\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0A' print(f"Sending ISO-TP message ({len(payload_to_send)} bytes): {payload_to_send.hex()}") stack.send(payload_to_send, timeout=0.5) # Add a timeout for sending # Wait a short moment for bus activity / reply time.sleep(0.1) # Attempt to receive an ISO-TP message (e.g., an ECU response) print("Attempting to receive ISO-TP message (timeout=1.0s)...") received_data = stack.recv(timeout=1.0) # Blocking receive with a timeout if received_data is not None: print(f"Received ISO-TP message ({len(received_data)} bytes): {received_data.hex()}") else: print("No ISO-TP message received within the timeout.") # Clean up the CAN bus bus.shutdown() print("CAN bus shut down.")