mock_can_data.py

""" Script to mock CAN data """
# This script automatically generates and sends CAN messages based off of the DBC file
# Ensure that you have can and cantools installed, which can be accomplished by running
# pip install -r requirements.txt
# Alternatively, you could also just run
# pip install can && pip install cantools

# If you are running this script with virtual CAN ensure that it is set up first
# You can run the below commands
# sudo modprobe vcan
# sudo ip link add dev vcan0 type vcan
# sudo ip link set up vcan0

import time
import random
import sys
import cantools
import can

# A negative value for NUM_MESSAGES will cause the script to send CAN messages forever
NUM_MESSAGES = -1
SLEEP_TIME_S = 1
CAN_MESSAGES = []

try:
    DB = cantools.database.load_file('system_can.dbc')
# pylint: disable=broad-except
except BaseException:
    print("ERROR: Must generate DBC file first")
    print("Run make codegen && make codegen_dbc")
    sys.exit(1)

# This can be edited depending on the CAN interface
CAN_BUS = can.interface.Bus('vcan0', bustype='socketcan')


def main():
    """ Main function """

    get_messages()
    iterate_message_and_signal()


def get_messages():
    """ Gets messages """

    for msg in DB.messages:
        CAN_MESSAGES.append(msg)


def iterate_message_and_signal():
    """ Iterates through messages and signals """

    num_messages_sent = 0
    while NUM_MESSAGES < 0 or NUM_MESSAGES > num_messages_sent:
        try:
            send_message()
            num_messages_sent += 1
            time.sleep(SLEEP_TIME_S)
        except KeyboardInterrupt:
            break
    print("\n" + str(num_messages_sent) + " CAN messages have been sent")


def send_message():
    """ Sends messages """

    msg = random.choice(CAN_MESSAGES)
    data = {}
    for signal in msg.signals:
        data[signal.name] = random.randint(0, pow(2, signal.length) - 1)
    new_data = msg.encode(data)
    message = can.Message(arbitration_id=msg.frame_id, data=new_data)
    CAN_BUS.send(message)


if __name__ == "__main__":
    main()