How to send serial data from Arduino to Visual Studio C# and vice versa

Projects Interfacing w/ Software on the Computer
1

I'm working on a project to read analog data from Arduino and then display it in Visual C# with zedgraph. I have a start button on my GUI that starts the reading of serial data from Arduino. I can do that with private void read_Tick method that open the arduino port, read serial data, display data on zedgraph, and then close the arduino for every 1 second. If you having a trouble understanding my words, here's the method:

private void read_Tick(object sender, EventArgs e)
{
    try
    {

        arduino.Open();

        LineItem kurvaKonsentrasi = zedGraphKonsentrasi.GraphPane.CurveList[0] as LineItem;


        IPointListEdit listKonsentrasi = kurvaKonsentrasi.Points as IPointListEdit;

        double time = (Environment.TickCount - timeStart) / 1000.0;

        float dataKonsentrasi = float.Parse(arduino.ReadLine(), CultureInfo.InvariantCulture.NumberFormat);
        listKonsentrasi.Add(time,Convert.ToDouble(dataKonsentrasi));

        arduino.Close();

        Scale xScale = zedGraphKonsentrasi.GraphPane.XAxis.Scale;
        if (time > xScale.Max - xScale.MajorStep)
        {
            xScale.Max = time + xScale.MajorStep;
            xScale.Min = xScale.Max - 30.0;
        }

        zedGraphKonsentrasi.AxisChange();

        zedGraphKonsentrasi.Invalidate();

    }
    catch (Exception fail)
    {
        if (arduino.IsOpen)
        {
            arduino.Close();
        }
    }

}

This method is called when I clicked start button. So, my problem is, I want to send string data "on" when I click start button. This string data is used for ordering Arduino to move the servo I attached with this code in void loop() before the analog readings.

if(Serial.available()>0){
    start = Serial.read();
      if(start == "on"){
        servoMotor.write(40);
  }
}

I know there's something wrong with what I'm doing because I cant start the servo. Can you give me advice what should I do to make the Visual C# send the command to arduino to start the servo once then arduino start the readings and then Visual C# read it?

*if you having a trouble understanding my code, I attached a full Arduino and C# code for GUI

concentration measurement.ino (6 KB)

2

bnrfly21:
with private void read_Tick method that open the arduino port, read serial data, display data on zedgraph, and then close the arduino for every 1 second.

I am not familiar with C# (I use Linux) but your program should open the serial port and keep it open until it is completely finished with the Arduino. Everytime the serial port is opened the Arduino will reset - which is unlikely to be what you want.

The examples in Serial Input Basics may be helpful. The technique in the 3rd example will be most reliable and could also be used in your c# code.

...R

3

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