Package: j1939
A new implementation of the CAN SAE J1939 standard for Python.WARNING: Currently this project is in alpha-state! Some of the features are not completely working!If you experience a problem or think the stack would not behave properly, do
not hesitate to open a ticket or write an email.
Pullrequests are of course even more welcome!The project uses thepython-canpackage to support multiple hardware drivers.
At the time of writing the supported interfaces areCAN over SerialCAN over Serial / SLCANIXXAT Virtual CAN InterfaceKvaserâ€™s CANLIBNEOVI InterfaceNI-CANPCAN Basic APISocketcanUSB2CAN InterfaceVectorVirtualisCANOverviewAn SAE J1939 CAN Network consists of multiple Electronic Control Units (ECUs).
Each ECU can have one or more Controller Applications (CAs). Each CA has its
own (unique) Address on the bus. This address is either acquired within the
address claiming procedure or set to a fixed value. In the latter case, the CA
has to announce its address to the bus to check whether it is free.The CAN messages in a SAE J1939 network are called Protocol Data Units (PDUs).
This definition is not completely correct, but close enough to think of PDUs
as the CAN messages.Featuresone ElectronicControlUnit (ECU) can hold multiple ControllerApplications (CA)ECU (CA) Naming according SAE J1939/81(under construction) full featured address claiming procedure according SAE J1939/81full support of transport protocol according SAE J1939/21 for sending and receiveingMessage Packaging and Reassembly (up to 1785 bytes)Transfer Protocol Transfer Data (TP.TD)Transfer Protocol Communication Management (TP.CM)Multi-Packet BroadcastsBroadcast Announce Message (TP.BAM)(under construction) Requests (global and specific)(under construction) correct timeout and deadline handling(under construction) almost complete testcoverageInstallationAs soon the package is available in your distro, it’s as easy as:$ pip install j1939In the meanwhile you can either download the wheel-package and issue the command:$ pip install j1939-0.1.0.dev1-py2.py3-none-any.whlor do the trick with:$ git clone https://github.com/benkfra/j1939.git
$ cd j1939
$ pip install .If you want to be able to change the code while using it, clone it then install it indevelop mode:$ git clone https://github.com/benkfra/j1939.git
$ cd j1939
$ pip install -e .Quick startTo simply receive all passing (public) messages on the bus you can subscribe to the ECU object.importloggingimporttimeimportcanimportj1939logging.getLogger('j1939').setLevel(logging.DEBUG)logging.getLogger('can').setLevel(logging.DEBUG)defon_message(pgn,data):"""Receive incoming messages from the bus

    :param int pgn:
        Parameter Group Number of the message
    :param bytearray data:
        Data of the PDU
    """print("PGN{}length{}".format(pgn,len(data)))defmain():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 busecu.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:importloggingimporttimeimportcanimportj1939logging.getLogger('j1939').setLevel(logging.DEBUG)logging.getLogger('can').setLevel(logging.DEBUG)classOwnCaToProduceCyclicMessages(j1939.ControllerApplication):"""CA to produce messages

    This CA produces simulated sensor values and cyclically sends them to
    the bus with the PGN 0xFEF6 (Intake Exhaust Conditions 1).
    """def__init__(self,name,device_address_preferred=None):# old fashion calling convention for compatibility with Python2j1939.ControllerApplication.__init__(self,name,device_address_preferred)defstart(self):"""Starts the CA
        (OVERLOADED function)
        """# add our timer eventself._ecu.add_timer(0.500,self.timer_callback)# call the super class functionreturnj1939.ControllerApplication.start(self)defstop(self):"""Stops the CA
        (OVERLOADED function)
        """self._ecu.remove_timer(self.timer_callback)defon_message(self,pgn,data):"""Feed incoming message to this CA.
        (OVERLOADED function)
        :param int pgn:
            Parameter Group Number of the message
        :param bytearray data:
            Data of the PDU
        """print("PGN{}length{}".format(pgn,len(data)))deftimer_callback(self,cookie):"""Callback for sending the IEC1 message

        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_addressifself.state!=j1939.ControllerApplication.State.NORMAL:# returning true keeps the timer event activereturnTruepgn=j1939.ParameterGroupNumber(0,0xFE,0xF6)data=[j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8,# Particulate Trap Inlet Pressure (SPN 81)j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8,# Boost Pressure (SPN 102)j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8,# Intake Manifold 1 Temperature (SPN 105)j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8,# Air Inlet Pressure (SPN 106)j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8,# Air Filter 1 Differential Pressure (SPN 107)j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_16_ARR[0],# Exhaust Gas Temperature (SPN 173)j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_16_ARR[1],j1939.ControllerApplication.FieldValue.NOT_AVAILABLE_8,# Coolant Filter Differential Pressure (SPN 112)]# SPN 105, Range -40..+210# (Offset -40)receiverTemperature=30data[2]=receiverTemperature+40self.send_message(6,pgn.value,data)# returning true keeps the timer event activereturnTruedefmain():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')# compose the name descriptor for the new caname=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 derived CA with given NAME and ADDRESSca=OwnCaToProduceCyclicMessages(name,128)# add CA to the ECUecu.add_ca(controller_application=ca)# by starting the CA it starts the address claiming procedure on the busca.start()time.sleep(120)print("Deinitializing")ca.stop()ecu.disconnect()if__name__=='__main__':main()CreditsThis implementation was initially inspired by theCANopen project of Christian Sandberg.
Thanks for your great work!Most of the informations about SAE J1939 are taken from the papers and the book ofCopperhill technologiesand from my many years of experience in J1939 of course :-)