Serialport: Need help please

[M Kibria]

Hi,

I am reading the output of a microcontroller through the serial port to show a value on a textbox and to draw a meter accordingly. I have written the datarecieved function which works OK as it follows.

void sp_datarecieved(object sender, SerialDataReceivedEventArgs e)
        {
          data = sp.ReadLine(); 
          temp = Convert.ToDouble(data);
          if (data != null)
            {
                for (int i = 0; i < 5000; i++)
                {
                    CrossThreadOperation.Invoke(txtTemp, delegate { txtTemp.Text = Convert.ToString(data.Trim()); });
                }
                }
                    }
 
 
 

For the graphics I have written the following.

private void temp_sen_Paint(object sender, PaintEventArgs e)
        {
            angle = 6.0 * temp;
            radian = (Math.PI * angle/ 180);
            x = Convert.ToInt32(192 - 162* Math.Cos(radian));
            y = Convert.ToInt32(202 - 162*Math.Sin(radian));
            Image img = Image.FromFile("C:\\mohammad\\p\\tem_sen\\temp_sen_serial\\drawing\\meter.JPG");
            e.Graphics.DrawImage(img, 0, 0);
            e.Graphics.DrawLine(mypen, x, y, 192, 202);
        }
 

The problem is when I check the value in 'angle = 6.0 * temp;' using a break point I can see 'temp' = 23 for example but I get 0.0 in 'angle' and that why the fraphics doesn't work as I want it to work.

I don't know what the problem is.

I would really be glad if someone can help me here.

Thanks in advance.

[Alex Bug]

You can try blocking object (lock object temp)... See here http://msdn.microsoft.com/en-us/library/c5kehkcz.aspx