P10 DMD Scrolling Message (While loop break)

[palavras010]

Hi everyone !!
I have stucked in a code of DMD master Library trying to control some Scrolling Message on my P10 96x32 Led Display. What i have already done is by pressing a button in my visual basic app sending some strings to the arduino and the scrolling message scrolls on my display. What i m trying to figure out is how to break this while loop on the code. Let me explain. Lets say i will press the button 5 times. What is gonna happen is seeing my message scrolls the display 5 times (Thats ok). Looks like arduino stores these orders somewhere.

What i want to do is break this 5 times loop by sending another order from my visual basic app. For example when another button pressed the loop should stop. Is there any way to make that happen ? Here are my codes

Arduino code :

Code: Select all

case 'S' : //SCROLING TEXT
    
    Timer1.initialize(1000 );           //period in microseconds to call ScanDMD. Anything longer than 5000 (5ms) and you can see flicker.
    Timer1.attachInterrupt( ScanDMD ); 
    dmd.clearScreen( true );
    dmd.selectFont(Arial_Black_16_ISO_8859_1);
    memset(stringb, 0, sizeof(stringb)); // set string contents to zero
    Serial.setTimeout(50); // second input timeout
    i = Serial.readBytesUntil('\n', stringb, sizeof(stringb)-1);
    dmd.drawMarquee(stringb,strlen(stringb),(32*DISPLAYS_ACROSS)-1,0);
    long start=millis();
    long timer=start;
    boolean ret=false;
    while(!ret) {
       if ((timer+30) < millis()) {
       ret=dmd.stepMarquee(-1,0);
       timer=millis();
       }
     }

Visual Basic Code :

Code: Select all

 Private Sub Button23_Click(sender As Object, e As EventArgs) Handles Button23.Click
        SerialPort1.WriteLine("S" & RichTextBox1.Text)
           End Sub

RichTextBox contains the strings i send to the arduino