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Thread: reading stream of bytes from serial port

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    Default reading stream of bytes from serial port

    Hello.
    I'm currently working on a project where I have to connect a camera to microcontroller and send a picture to PC.
    The interfacing part is done but now I'm struggling with capturing the data on the PC side. Microcontroller sends a complete bmp file to PC in chunks: firstly header then info header and then data. And this is my problem I don't know how to capture all that and save it into bmp.

    I appreciate any help
    Regards
    Kris


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    Default Re: reading stream of bytes from serial port

    Can you just append each data chunk onto the end of an array or file?

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    Default Re: reading stream of bytes from serial port

    Hi
    Thank for the reply.

    I am using java.comms package to communicate with microcontroller.
    Yes my problem is with protocol.
    I can read a single byte and send a byte but i have problems with reading loads of byte being sent at once. The data that are sent from microcontroller are image data that come from camera i connected to microcontroller so there is loads of data.

    while(true){
                System.out.println("Enter command");
                while(in.hasNextInt()){
                    i = in.nextInt();
                    byte b = (byte)i;
                    a.UARTputc(b);          //send command
     
                    byte s = a.UARTgetb();  //check if something came back
                    System.out.println(s);    //for debug
                    if(s == 119){           //start of picture ascci for 'w'
                        do{
                            temp = a.UARTgetb();
                            pic[count] = temp;
                            count++;
                            System.out.println(count); //for debug
                        }while(temp != 10);//ascii for '\n'

    this part i have now does not even get into the do-while loop

    This is for reading the port:
            case SerialPortEvent.DATA_AVAILABLE:
                readBuffer = new byte[8];
     
                    try {
                    while (inputStream.available() > 0) {
                        int numBytes = inputStream.read(readBuffer);
                    }
                    int byteCount = 0;
                    for (int i = 0; i < currentWrite.length; i++) {
                        if (currentWrite[i] == readBuffer[i]) {
                            byteCount++;
                        }
                    }
                    if (byteCount != currentWrite.length) {
                        dataIn = true;
                    }
                } catch (IOException e) {System.out.println(e);}
                break;
            }

    public void UARTputc(byte b) throws Exception{
            byte[] data = {b};
     
            sPort.write(data);
            utils.pause(100);
        }
     
        public byte UARTgetb(){
            byte t=0;
            byte b[] = sPort.read();
            t = b[0];
     
            return t;
        }

    Any advice is appreciated

    Regards

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