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J1939 and Car PC

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  • J1939 and Car PC

    Does anyone have any insight or if it is even possible to hook up an in-vehicle PC to a J1939 9-pin port and have that connection supply the vehicle data as well as the power to the in-car PC?


  • #2
    Yes. It is doable. But need a device in-between for signal relay.
    A good reference is Au Group Electronics J1939 Interpreter, which can relay bi-directional between the PC and J1939 bus.

    Au SAE J1939 Interpreter, a palm-size device with SAE J1939 CAN (Controller Area Network) bus Interface and RS232 Interface, is capable of interpreting most-frequently-used SAE J1939 engine signals to RS232 ASCII String (a popular Human readable text format).
    Device Overview:

    Device with cable connected:

    Typical network topology and J1939 message in text format (similar to AT command)

    Major hardware features of Au SAE J1939 Interpreter are listed below:
    • 600W TVS (Transient Voltage Suppressor) protection on CAN bus
    • Compact size: 3" L X 1-5/8"W X 3/4”H
    • Enclosure color: Black or PC white
    • Operating temperature: -40 ˚F to 185 ˚F (-40 ˚C to 85 ˚C)
    • Power supply: +9V~+14.2V DC, +12V nominal, 250mA max
    • 2 LED indicators: Power LED: for power indicator; Comm LED: for event indication
    • 1 push button: Not used in normal operation, used for bootloading only (for in-field firmware updates)
    • 1 DB9 Male "BUS" Interface
    • 1 RS232 Interface (default baud rate: 115.2K).

    For your quick reference, I have the engine Basic supported SAE J1939 parameters listed here:
    Au SAE J1939 Interpreter Engine Basic Edition supports all of the Value Package functions/parameters, plus 39 more SAE J1939 engine parameters (49 parameters in total):

    The first 10 parameter and and source address claim for J1939 network management are also supported by Value Package edition(s):
    • Engine Speed (RPM)
    • Electrical Potential (Voltage), Switched
    • Engine Turbocharger Boost Pressure
    • Engine % Load at Current Speed
    • Engine Fuel Rate
    • Engine Coolant Temperature
    • Engine Instant Fuel Economy
    • Engine Intake Manifold 1 Temperature
    • Engine Total Hours of Operation (also known as engine hour)
    • Engine Oil Pressure
    • Address Claiming
    • Address CANNOT Claim
    • Response for Address Claim Request
    • Address Conflict Response with Contention

    and 39 more parameters:

    • A/C High Pressure Fan Switch
    • Accelerator Pedal Position
    • Actual Engine - Percent Torque
    • Battery Potential (Voltage) Switched
    • Cruise Control Active
    • Engine Air Inlet Pressure
    • Engine Air Shutoff Command Status
    • Engine Alarm Acknowledge
    • Engine Alarm Output Command Status
    • Engine Clock
    • Engine Clock Setup
    • Engine Coolant Level
    • Engine Coolant Pressure
    • Engine EGR Mass Flow Rate
    • Engine Exhaust Gas Temperature
    • Engine Fuel Temperature
    • Engine Idle Shutdown has shutdown engine
    • Engine Inlet Air Mass Flow Rate
    • Engine Idle Shutdown (IS) Driver Alert Mode
    • Engine IS Timer Function
    • Engine IS Timer Override
    • Engine IS Timer State
    • Engine Oil Level
    • Engine Oil Temperature 1
    • Engine Over speed Test
    • EPS Approaching shutdown
    • Engine Protection System (EPS) Configuration
    • EPS Timer Override
    • EPS Timer State
    • EPS has Shutdown Engine
    • Engine Total Vehicle Distance
    • Engine Trip Distance
    • Engine Wait to Start Lamp
    • Nominal Friction - Percent Torque
    • Refrigerant High Pressure Switch
    • Refrigerant Low Pressure Switch
    • SAE J1939 Fuel Level
    • Water-in-Fuel indicator
    • Wheel Based Vehicle Speed (MPH)

    Other tech. features:
    • Source address field configurable
    • Engine Hour auto request and command request
    • Device ID, Firmware ID and Serial Number ID included
    • Engine Clock setup command, will setup engine clock via J1939 (require engine support engine clock setup on J1939).
    • Engine VIN auto request and command request