Recording OBD Scanner USB Data with Visual Studio 2017

Introduction to OBD-II Data Logging

For automotive enthusiasts, mechanics, and engineers, accessing and interpreting vehicle data is crucial. On-Board Diagnostics II (OBD-II) systems provide a wealth of information about a vehicle’s performance and health. Recording this data can be invaluable for diagnostics, performance tuning, and research. This article will guide you through the process of Recording Obd Scanner Usb Data With Visual Studio 2017, empowering you to leverage this powerful development environment for automotive data acquisition.

Understanding OBD-II and Data Acquisition

OBD-II is a standardized system that allows you to access data from your vehicle’s Engine Control Unit (ECU) and other modules. This data includes parameters like engine speed (RPM), coolant temperature, throttle position, and much more. To access this data, you need:

An OBD-II Scanner: This hardware device plugs into your vehicle’s OBD-II port, typically located under the dashboard. Scanners come in various forms, including USB-based scanners, Bluetooth scanners, and Wi-Fi scanners. For this guide, we’ll focus on USB OBD scanners.
Visual Studio 2017: Microsoft’s Integrated Development Environment (IDE) provides the tools and libraries necessary to interact with USB devices and process data.
OBD-II Communication Protocol Knowledge: Understanding protocols like CAN (Controller Area Network) or ISO 15765 is helpful for advanced data interpretation, though libraries can abstract much of this complexity.

Setting Up Your Environment

Before you begin recording OBD scanner USB data with Visual Studio 2017, ensure your environment is correctly configured:

Install Visual Studio 2017: If you haven’t already, download and install Visual Studio 2017 Community Edition (or a Professional/Enterprise version). Ensure you include the necessary workloads for C++ or C# development, depending on your preferred programming language.
Install USB Driver for your OBD Scanner: Your OBD scanner should come with a USB driver. Install this driver on your computer to allow communication between your PC and the scanner. Refer to your scanner’s documentation for driver installation instructions.
Identify your OBD Scanner’s COM Port (Windows):
- Connect your USB OBD scanner to your computer and vehicle.
- Open Device Manager in Windows (search for “Device Manager” in the Start Menu).
- Look for “Ports (COM & LPT)”. Your OBD scanner should appear as a COM port (e.g., “USB Serial Port (COM3)”). Note down the COM port number, as you’ll need it later.

Developing your OBD-II Data Recording Application in Visual Studio 2017

Now, let’s create a simple application in Visual Studio 2017 to record OBD scanner USB data. We’ll outline the steps for both C# and C++.

Option 1: C# Application

C# offers a straightforward approach for serial port communication, making it suitable for recording OBD scanner data.

Create a New C# Console Application:
- Open Visual Studio 2017.
- Go to File > New > Project.
- Select “Console App (.NET Framework)” under Visual C#.
- Name your project (e.g., “OBDDataLogger”) and click “OK”.
Add SerialPort Class:
- In your Program.cs file, include the System.IO.Ports namespace:
```
using System.IO.Ports;
using System;
```

Implement Data Recording Logic:

Modify your Main method to initialize the SerialPort object and handle data reception. Replace "COM3" with the actual COM port number of your OBD scanner.

class Program
{
    static void Main(string[] args)
    {
        SerialPort port = new SerialPort("COM3", 9600); // Adjust baud rate if needed

        try
        {
            port.Open();
            Console.WriteLine("Serial port opened. Listening for OBD-II data...");

            port.DataReceived += new SerialDataReceivedEventHandler(Port_DataReceived);

            Console.WriteLine("Press any key to stop recording...");
            Console.ReadKey();

            port.Close();
            Console.WriteLine("Serial port closed. Recording stopped.");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error: {ex.Message}");
        }
    }

    private static void Port_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        SerialPort port = (SerialPort)sender;
        string data = port.ReadExisting();
        Console.Write(data); // You can process and save the data here instead of just printing
    }
}

Explanation:
- SerialPort port = new SerialPort("COM3", 9600);: Creates a SerialPort object, specifying the COM port and baud rate. You may need to adjust the baud rate (9600 is a common starting point for OBD-II). Consult your scanner documentation if necessary.
- port.Open();: Opens the serial port for communication.
- port.DataReceived += new SerialDataReceivedEventHandler(Port_DataReceived);: Attaches an event handler (Port_DataReceived) to the DataReceived event. This event is triggered whenever data is received on the serial port.
- Port_DataReceived method: Reads the incoming data using port.ReadExisting() and currently prints it to the console. Crucially, you should modify this method to process and save the OBD-II data to a file or database for later analysis.

Run your application: Press Ctrl + F5 to run your application without debugging. Start your vehicle’s engine. You should see raw OBD-II data streaming in the console window.

Option 2: C++ Application

C++ provides more low-level control and is often preferred for performance-critical applications.

Create a New C++ Empty Project:
- Open Visual Studio 2017.
- Go to File > New > Project.
- Select “Empty Project” under Visual C++.
- Name your project (e.g., “OBDDataLoggerCPP”) and click “OK”.
Add a C++ Source File:
- In Solution Explorer, right-click on “Source Files” > Add > New Item.
- Select “C++ File (.cpp)”.
- Name it (e.g., main.cpp) and click “Add”.

Include Necessary Headers and Implement Serial Port Communication:

#include <iostream>
#include <Windows.h>
#include <string>

using namespace std;

int main() {
    HANDLE hSerial;
    string comPort = "\\.\COM3"; // Replace COM3 with your actual COM port

    hSerial = CreateFileA(comPort.c_str(),
        GENERIC_READ | GENERIC_WRITE,
        0,
        0,
        OPEN_EXISTING,
        0,
        NULL);

    if (hSerial == INVALID_HANDLE_VALUE) {
        cerr << "Error opening serial port: " << GetLastError() << endl;
        return 1;
    }

    DCB dcbSerialParams = { 0 };
    dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
    if (!GetCommState(hSerial, &dcbSerialParams)) {
        cerr << "Error getting serial port state: " << GetLastError() << endl;
        CloseHandle(hSerial);
        return 1;
    }

    dcbSerialParams.BaudRate = CBR_9600; // Set baud rate (adjust if needed)
    dcbSerialParams.ByteSize = 8;
    dcbSerialParams.StopBits = ONESTOPBIT;
    dcbSerialParams.Parity = NOPARITY;
    if (!SetCommState(hSerial, &dcbSerialParams)) {
        cerr << "Error setting serial port state: " << GetLastError() << endl;
        CloseHandle(hSerial);
        return 1;
    }

    COMMTIMEOUTS timeouts = { 0 };
    timeouts.ReadIntervalTimeout = 50;
    timeouts.ReadTotalTimeoutConstant = 50;
    timeouts.ReadTotalTimeoutMultiplier = 10;
    timeouts.WriteTotalTimeoutConstant = 50;
    timeouts.WriteTotalTimeoutMultiplier = 10;
    if (!SetCommTimeouts(hSerial, &timeouts)) {
        cerr << "Error setting timeouts: " << GetLastError() << endl;
        CloseHandle(hSerial);
        return 1;
    }

    char buffer[256];
    DWORD bytesRead;

    cout << "Serial port opened. Listening for OBD-II data..." << endl;
    cout << "Press any key to stop recording..." << endl;

    while (!_kbhit()) { // Loop until a key is pressed
        if (ReadFile(hSerial, buffer, sizeof(buffer) - 1, &bytesRead, NULL)) {
            if (bytesRead > 0) {
                buffer[bytesRead] = ''; // Null-terminate the buffer
                cout << buffer; // Process and save data here instead of printing
            }
        }
        else {
            cerr << "Error reading from serial port: " << GetLastError() << endl;
            break;
        }
    }

    CloseHandle(hSerial);
    cout << "nSerial port closed. Recording stopped." << endl;
    return 0;
}

Explanation:
- Includes <Windows.h> for Windows serial port API.
- CreateFileA opens the serial port.
- DCB structure configures serial port parameters (baud rate, data bits, etc.).
- ReadFile reads data from the serial port into the buffer.
- Similar to the C# example, you need to modify the data processing part (currently cout << buffer;) to save the data.

Run your application: Press Ctrl + F5 to run your C++ application.

Processing and Saving OBD-II Data

The console output in the examples above shows raw data. To make this data useful, you need to:

Understand OBD-II PIDs (Parameter IDs): OBD-II data is organized using PIDs. Each PID represents a specific parameter (e.g., PID 010C for engine RPM). You’ll need to consult OBD-II PID documentation to interpret the raw data bytes.
Implement Data Parsing: Write code to parse the raw data stream based on the OBD-II protocol and PIDs you are interested in.
Save Data: Modify the Port_DataReceived (C#) or the data processing loop (C++) to save the parsed data to a file (e.g., CSV, text file) or a database. You can use file I/O operations in both C# and C++ for saving data.

Conclusion

Recording OBD scanner USB data with Visual Studio 2017 provides a flexible and powerful way to access and analyze vehicle information. By following the steps outlined in this guide and expanding upon the basic examples, you can create sophisticated OBD-II data logging applications tailored to your specific needs. Remember to consult OBD-II documentation and your scanner’s manual for detailed information about supported PIDs and communication protocols to maximize the effectiveness of your data recording efforts. This capability opens up numerous possibilities for automotive diagnostics, performance analysis, and custom vehicle applications.