Serialport with CANBUS (OBD) communication

See more:

C#

VB

I am trying to communicate with CANBUS using FTDI(Serial Port Converter) through OBD Connector. I need to just send OBD-PID commands through SerialPort.

https://i.stack.imgur.com/7NNok.png[^]

What I have tried:

I tried to use FTD2XX_NET Library, with following code :

UInt32 ftdiDeviceCount = 0;
    FTDI.FT_STATUS ftStatus = FTDI.FT_STATUS.FT_OK;

    // Create new instance of the FTDI device class
    FTDI myFtdiDevice = new FTDI();

    // Determine the number of FTDI devices connected to the machine
    ftStatus = myFtdiDevice.GetNumberOfDevices(ref ftdiDeviceCount);
    // Check status
    if (ftStatus == FTDI.FT_STATUS.FT_OK)
    {
        Console.WriteLine("Number of FTDI devices: " + ftdiDeviceCount.ToString());
        Console.WriteLine("");
    }
    else
    {
        // Wait for a key press
        Console.WriteLine("Failed to get number of devices (error " + ftStatus.ToString() + ")");
        Console.ReadKey();
        return;
    }

    // If no devices available, return
    if (ftdiDeviceCount == 0)
    {
        // Wait for a key press
        Console.WriteLine("Failed to get number of devices (error " + ftStatus.ToString() + ")");
   
        return;
    }

    // Allocate storage for device info list
    FTDI.FT_DEVICE_INFO_NODE[] ftdiDeviceList = new FTDI.FT_DEVICE_INFO_NODE[ftdiDeviceCount];

    // Populate our device list
    ftStatus = myFtdiDevice.GetDeviceList(ftdiDeviceList);

    if (ftStatus == FTDI.FT_STATUS.FT_OK)
    {
        for (UInt32 i = 0; i < ftdiDeviceCount; i++)
        {
            Console.WriteLine("Device Index: " + i.ToString());
            Console.WriteLine("Flags: " + String.Format("{0:x}", ftdiDeviceList[i].Flags));
            Console.WriteLine("Type: " + ftdiDeviceList[i].Type.ToString());
            Console.WriteLine("ID: " + String.Format("{0:x}", ftdiDeviceList[i].ID));
            Console.WriteLine("Location ID: " + String.Format("{0:x}", ftdiDeviceList[i].LocId));
            Console.WriteLine("Serial Number: " + ftdiDeviceList[i].SerialNumber.ToString());
            Console.WriteLine("Description: " + ftdiDeviceList[i].Description.ToString());
            Console.WriteLine("");
        }
    }


    // Open first device in our list by serial number
    ftStatus = myFtdiDevice.OpenBySerialNumber(ftdiDeviceList[0].SerialNumber);
    if (ftStatus != FTDI.FT_STATUS.FT_OK)
    {
        // Wait for a key press
        Console.WriteLine("Failed to open device (error " + ftStatus.ToString() + ")");
        Console.ReadKey();
        return;
    }



    // Perform loop back - make sure loop back connector is fitted to the device
    // Write string data to the device
    byte[] dataToWrite = new byte[] { 0x00, 0x00, 0x07, 0xdf, 0x09, 0x02 };
    UInt32 numBytesWritten = 0;
    // Note that the Write method is overloaded, so can write string or byte array data

    ftStatus = myFtdiDevice.Write(dataToWrite, dataToWrite.Length, ref numBytesWritten);
    if (ftStatus != FTDI.FT_STATUS.FT_OK)
    {
        // Wait for a key press
        Console.WriteLine("Failed to write to device (error " + ftStatus.ToString() + ")");
        Console.ReadKey();
        return;
    }


    // Check the amount of data available to read
    // In this case we know how much data we are expecting, 
    // so wait until we have all of the bytes we have sent.
    UInt32 numBytesAvailable = 0;
    UInt32 numBytesRead = 0;

    string readData = "";
    while (readData == "")
    {
        ftStatus = myFtdiDevice.Read(out readData, numBytesAvailable, ref numBytesRead);
    }
    if (ftStatus != FTDI.FT_STATUS.FT_OK)
    {
        // Wait for a key press
        Console.WriteLine("Failed to get number of bytes available to read (error " + ftStatus.ToString() + ")");
        Console.ReadKey();
        return;
    }


    // Close our device
    ftStatus = myFtdiDevice.Close();

    // Wait for a key press
    Console.WriteLine(readData + " Finished.");

This code suppsoes to send (

0x00, 0x00, 0x07, 0xdf, 0x09, 0x02 

) which returns VIN, but the connector does not seem to send and not getting any response from the OBD.

I am not sure what am I doing wrong, I would appreciate your help.

Thanks,