can-j1939-ttpsc 1.0.4

Fork of SAE J1939 stack implementation, originally created by Juergen Heilgemeir

Overview

This is a fork of the https://github.com/juergenH87/python-can-j1939 project, it essentially adds the possibility to get the origin of the message. For more information please check the readme file in the author’s project.

Installation

Install can-j1939 with pip:

$ pip install can-j1939-ttpsc

or do the trick with:

$ git clone https://github.com/ttpscmolinaf/python-can-j1939
$ cd j1939
$ pip install .

Upgrade

Upgrade an already installed can-j1939 package:

$ pip install --upgrade can-j1939

Quick start

To simply receive all passing (public) messages on the bus you can subscribe to the ECU object.

import logging
import time
import can
import j1939

logging.getLogger('j1939').setLevel(logging.DEBUG)
logging.getLogger('can').setLevel(logging.DEBUG)

def on_message(priority, pgn, sa, timestamp, data):
    """Receive incoming messages from the bus

    :param int priority:
        Priority of the message
    :param int pgn:
        Parameter Group Number of the message
    :param int sa:
        Source Address of the message
    :param int timestamp:
        Timestamp of the message
    :param bytearray data:
        Data of the PDU
    """
    print("PGN {} length {}".format(pgn, len(data)))

def main():
    print("Initializing")

    # create the ElectronicControlUnit (one ECU can hold multiple ControllerApplications)
    ecu = j1939.ElectronicControlUnit()

    # Connect to the CAN bus
    # Arguments are passed to python-can's can.interface.Bus() constructor
    # (see https://python-can.readthedocs.io/en/stable/bus.html).
    # ecu.connect(bustype='socketcan', channel='can0')
    # ecu.connect(bustype='kvaser', channel=0, bitrate=250000)
    ecu.connect(bustype='pcan', channel='PCAN_USBBUS1', bitrate=250000)
    # ecu.connect(bustype='ixxat', channel=0, bitrate=250000)
    # ecu.connect(bustype='vector', app_name='CANalyzer', channel=0, bitrate=250000)
    # ecu.connect(bustype='nican', channel='CAN0', bitrate=250000)

    # subscribe to all (global) messages on the bus
    ecu.subscribe(on_message)

    time.sleep(120)

    print("Deinitializing")
    ecu.disconnect()

if __name__ == '__main__':
    main()

A more sophisticated example in which the CA class was overloaded to include its own functionality:

import logging
import time
import can
import j1939

logging.getLogger('j1939').setLevel(logging.DEBUG)
logging.getLogger('can').setLevel(logging.DEBUG)

# compose the name descriptor for the new ca
name = j1939.Name(
    arbitrary_address_capable=0,
    industry_group=j1939.Name.IndustryGroup.Industrial,
    vehicle_system_instance=1,
    vehicle_system=1,
    function=1,
    function_instance=1,
    ecu_instance=1,
    manufacturer_code=666,
    identity_number=1234567
    )

# create the ControllerApplications
ca = j1939.ControllerApplication(name, 128)


def ca_receive(priority, pgn, source, timestamp, data):
    """Feed incoming message to this CA.
    (OVERLOADED function)
    :param int priority:
        Priority of the message
    :param int pgn:
        Parameter Group Number of the message
    :param intsa:
        Source Address of the message
    :param int timestamp:
        Timestamp of the message
    :param bytearray data:
        Data of the PDU
    """
    print("PGN {} length {}".format(pgn, len(data)))

def ca_timer_callback1(cookie):
    """Callback for sending messages

    This callback is registered at the ECU timer event mechanism to be
    executed every 500ms.

    :param cookie:
        A cookie registered at 'add_timer'. May be None.
    """
    # wait until we have our device_address
    if ca.state != j1939.ControllerApplication.State.NORMAL:
        # returning true keeps the timer event active
        return True

    # create data with 8 bytes
    data = [j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8] * 8

    # sending normal broadcast message
    ca.send_pgn(0, 0xFD, 0xED, 6, data)

    # sending normal peer-to-peer message, destintion address is 0x04
    ca.send_pgn(0, 0xE0, 0x04, 6, data)

    # returning true keeps the timer event active
    return True


def ca_timer_callback2(cookie):
    """Callback for sending messages

    This callback is registered at the ECU timer event mechanism to be
    executed every 500ms.

    :param cookie:
        A cookie registered at 'add_timer'. May be None.
    """
    # wait until we have our device_address
    if ca.state != j1939.ControllerApplication.State.NORMAL:
        # returning true keeps the timer event active
        return True

    # create data with 100 bytes
    data = [j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8] * 100

    # sending multipacket message with TP-BAM
    ca.send_pgn(0, 0xFE, 0xF6, 6, data)

    # sending multipacket message with TP-CMDT, destination address is 0x05
    ca.send_pgn(0, 0xD0, 0x05, 6, data)

    # returning true keeps the timer event active
    return True

def main():
    print("Initializing")

    # create the ElectronicControlUnit (one ECU can hold multiple ControllerApplications)
    ecu = j1939.ElectronicControlUnit()

    # Connect to the CAN bus
    # Arguments are passed to python-can's can.interface.Bus() constructor
    # (see https://python-can.readthedocs.io/en/stable/bus.html).
    # ecu.connect(bustype='socketcan', channel='can0')
    # ecu.connect(bustype='kvaser', channel=0, bitrate=250000)
    ecu.connect(bustype='pcan', channel='PCAN_USBBUS1', bitrate=250000)
    # ecu.connect(bustype='ixxat', channel=0, bitrate=250000)
    # ecu.connect(bustype='vector', app_name='CANalyzer', channel=0, bitrate=250000)
    # ecu.connect(bustype='nican', channel='CAN0', bitrate=250000)
    # ecu.connect('testchannel_1', bustype='virtual')

    # add CA to the ECU
    ecu.add_ca(controller_application=ca)
    ca.subscribe(ca_receive)
    # callback every 0.5s
    ca.add_timer(0.500, ca_timer_callback1)
    # callback every 5s
    ca.add_timer(5, ca_timer_callback2)
    # by starting the CA it starts the address claiming procedure on the bus
    ca.start()

    time.sleep(120)

    print("Deinitializing")
    ca.stop()
    ecu.disconnect()

if __name__ == '__main__':
    main()

Credits

This implementation was taken from https://github.com/juergenH87/python-can-j1939, as we needed to get information of the bus for the message that was received by the library.

Thanks for your great work Juergen :)!