C# USB CDC application help

[ranaya]

Hello every1.......

I'm using USB CDC class for the comunication between my lpc1769 device and the host. A C# form application is developed to handle host communication. So usb port / connection enumerate as a com port on host side. First I need to confidure my device. It's a data logger. From the host I send configuration details of the data logger channels to the device by sending few characters (if char1 = v, it says channel1 = voltage).

After the configuration is done record command will be sent and device starts to log data. Upto this point my application works fine. Now I need to transfer logged data to the host. So data should be trasmitted continously. For the above cases I use only 2 methods.

delegate void SetTextCallback(string text);

private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e){
            try{
                SetText(serialPort1.ReadExisting());      //delegate one
            }
            catch{
                btnClose_Click(this, null);
            }
        }


private void SetText(String text){
            inCom = text.ToCharArray(0, 1);
          
            if (inCom[0] == 'A'){                               //ready to configure

                if (txtDataReceived.InvokeRequired){
                    SetTextCallback d = new SetTextCallback(SetText);
                    Invoke(d, new object[] { text });
                }else{
                    txtDataReceived.Clear();
                    txtDataReceived.Text = "Configure...";
                }

            }else if (inCom[0] == 'B'){                        //load recorded data

                if (txtDataReceived.InvokeRequired){
                    SetTextCallback d = new SetTextCallback(SetText);
                    Invoke(d, new object[] { text });
                }else{
                    txtDataReceived.Clear();
                    txtDataReceived.Text = "Load...";
                }
          
            }else{
                
            }
  }

How to recieved continous data via the serial port ? any code examples ideas would be appreciated.

Thank you

 

[bigdogguru]

In what format is the data to be transmitted to the host, integer, float, text all of above?

Can you provide an example data stream?

BigDog

 

[ranaya]

hi.. thanx for the response...

device sends a byte array to the host. MCu code looks like :

res = f_read(&File, buffer, sizeof(buffer), &br);
USB_WriteEP(CDC_DEP_IN,(unsigned char *)&buffer[0],64);

Read a 64byte (buffer) from the sd card and write them to the endpoint. If I print the byte array read from sd card in lpcxpresso ide it displays

1.00
2.00
3.00........

Now I need to transfer them to the host. Send 1 data stream (64 byte array) and from the host it will be stored somewhere and continue next transmission.

 

[ranaya]

Hi...... I could solve the data receiving problem. Now my c# application can receive the data sent by the MCU. But there's another problem. Received data sequence is not correct. Expected sequence is 0.00, 1.00, 2.00....., 49.00, 0.00, 1.00........

Instead i received this :-
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.

14.00
15.00
16.00
17.00
18.00
19.00
20.00
21.00
22.00

1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00

.00
39.00
40.00
41.00
42.00
43.00
44.00
45.00
46.00
47
.00
15.00
16.00
17.00
18.00
19.00
20.00
21.00
22.00
23
0
27.00
28.00
29.00
30.00
31.00
32.00
33.00
34.00
35.0
7.00
28.00
29.00
30.00
31.00
32.00
33.00
34.00
35.00
3

So definitely the problem might be in my c# code. I reduce the data sending rate to the host inside the MCU. result's same. I use above c# event handling code. what could be the mistake ? i didn't use timeout parameters for the serial port in c#. pls can some1 explain me

Thanx