character sent to serial port not read by arduino

Question

I am sending a character from visual studio C# to the serial port and I want arduino to read the character and do some work. But, its not reading it correctly. I have tested the arduino program using the serial monitor and it is working perfectly.Here's my C# code.

private void startBit_Click(object sender, EventArgs e)
    {
        char start = '!';
        byte[] buffer = new byte[] { Convert.ToByte(start) };
        timerRealTimeData.Enabled = true;
        serialPort1.PortName = "COM29";
        serialPort1.BaudRate = 9600;
        serialPort1.DtrEnable = true;
        serialPort1.Open();
        serialPort1.Write(buffer, 0, 1);
        if (serialPort1.IsOpen)
        {

            Start.Enabled = false;
            Stop.Enabled = true;

        }
    }

Here's the arduino code for reading the serial port

char incomingByte;
void setup()
{
  Serial.begin(9600);
  pinMode(13,OUTPUT);

}
 void loop()
 {

 if(Serial.available() > 0) {

  incomingByte = Serial.read();
  if(incomingByte=='!')
      {
        digitalWrite(13,HIGH);
        delay(2000);
        digitalWrite(13,LOW);

      }
  }

}

I am stuck on this for a long time.Any help is appreciated

Be more specific with your problem description. "It doesn't work" or, in this case, "it's not reading it correctly" tells us pretty much nothing about your issue other than the fact that it just doesn't work. Which we assume is the case because of the post's existence in the first place. — tnw
Becouse you are new here, do not forget to mark as accepted the answer that satisfy your question. We have thousands of unanswerd questions only because people forget to to it. — FeliceM

FeliceM FeliceM · Accepted Answer · 2013-05-17T18:55:13

Try to read the equivalent Ascii (33) using an int instead of a char. Also change the line

if(Serial.available() > 0)

To

if(Serial.available())

Some reference for you. Here

character sent to serial port not read by arduino

2 Answers