help with reading from serial port

I'm newbie in programming. Want to send series of pulses (square waves) to PC and use C# to count the incoming pulses and display it like a running counter (real time). Frequency of pulses: 1-10Hz

however i cant figure out how to do this. Should i connect the pulses to CTS of serial port? (instead of sending the pulses via TX pin), and how about the logic level of Serial port? my pulses is 5V (hi), and 0V (low). Do i need MAX 232?

how to keep reading (listening) to the port while the application does something else?

please help. i need enlightenment from expert here :) some sample code will be much appreciated.

here is some sample code for connecting to a serial barcode scanner and "waiting" for it to scan a barcode and retrieving the data that was scanned. the second code sample is how to send data "commands" through the serial port to a connected device. the second code sample is sending a command to a serial scale and having it send back it's current weight.
__________________________________________________
public SerialPort sp;
private delegate void SetTextDeleg(string text);

sp = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
this.sp.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);

void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
       try
       {
           Thread.Sleep(500);
           string x = sp.ReadLine();
           this.BeginInvoke(new SetTextDeleg(si_DataReceived), new object[] { x });
        }
        catch
       { }
}

private void si_DataReceived(string data)
{
       string scannedData = data.Trim();
       // do work with data
}
_________________________________________

second example
_________________________________________

SerialPort sp = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
sp.Open();
sp.Write("P"); // This is a "PRINT" command for the scale which returns the weight

string inputChar = Convert.ToChar(sp.ReadChar()).ToString();
// this will read each character that is returned from the serial port.
_________________________________________________

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Ryan Alford18y ago
here is some sample code for connecting to a serial barcode scanner and "waiting" for it to scan a barcode and retrieving the data that was scanned. the second code sample is how to send data "commands" through the serial port to a connected device. the second code sample is sending a command to a serial scale and having it send back it's current weight.
__________________________________________________
public SerialPort sp;
private delegate void SetTextDeleg(string text);

sp = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
this.sp.DataReceived += new SerialDataReceivedEventHandler(sp_DataReceived);

void sp_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
       try
       {
           Thread.Sleep(500);
           string x = sp.ReadLine();
           this.BeginInvoke(new SetTextDeleg(si_DataReceived), new object[] { x });
        }
        catch
       { }
}

private void si_DataReceived(string data)
{
       string scannedData = data.Trim();
       // do work with data
}
_________________________________________

second example
_________________________________________

SerialPort sp = new SerialPort("COM1", 9600, Parity.None, 8, StopBits.One);
sp.Open();
sp.Write("P"); // This is a "PRINT" command for the scale which returns the weight

string inputChar = Convert.ToChar(sp.ReadChar()).ToString();
// this will read each character that is returned from the serial port.
_________________________________________________
0