Reputation: 35
I have a form in which I am able to receive data and show it in a richtextbox, but what I need is to read the data that is coming continuously from serial port and decode accordingly.
For ex: I am receiving data in bytes in the format as 36 0 0 0 1 0 0...., 36
is used to indicate start of frame n rest are the data through which an event will be fired.
My code:
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
// get number off bytes in buffer
Bytenumber = serialPort1.BytesToRead;
// read one byte from buffer
ByteToRead = serialPort1.ReadByte();
this.Invoke(new EventHandler(DoUpdate));
}
Above code is used to receive data and fire an event. The code for the event is as follows:
int w=0;
public void DoUpdate(object sender, System.EventArgs e)
{
byte[] t = new byte[Bytenumber];
for(int g=0; g<Bytenumber;g++)
{
t[g] = Convert.ToByte(ByteToRead);
}
w++;
// richTextBox1.Text += ByteToRead;
if (ByteToRead == 36)
{
for (int r = 0; r <= 73; r++)
{
if (ByteToRead == 0x01)
{
timer1.Start();
w++;
}
}
}
}
In the data received event handler I am looking for 36
(i.e., start of frame) once I get that I am looking for 1s from the buffer. The problem is when I get 36
(i.e., start of frame) the same data is retained in the if loop and tries to compare with 1 which will not be true @ any case. All I need is to read the next bytes of data coming from the buffer once I get 36.
Upvotes: 0
Views: 1965
Reputation: 273766
I can spot a few problems. A little code-review:
Bytenumber = serialPort1.BytesToRead;
ByteNumber is the Bytes-to-Read at this moment. It is not thread-safe to keep this in a member field.
ByteToRead = serialPort1.ReadByte();
This only reads 1 Byte. And then, on another thread:
byte[] t = new byte[Bytenumber]; // ByteNumber may have changed already
for(int g=0; g<Bytenumber;g++)
{
t[g] = Convert.ToByte(ByteToRead); // store the _same_ byte in all elements
}
What you should do (not complete code):
private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
// get number off bytes in buffer
int n = serialPort1.BytesToRead;
byte[] buffer = new byte[n];
// read one byte from buffer
int bytesToProcess = serialPort1.Read(buffer, 0, n);
this.Invoke(UpdateMethod, buffer, bytesToProcess);
}
But do search the internet for working code. I just made this up.
Upvotes: 1