matrixDisplay.cpp

00001 #include "mbed.h"
00002 #include "matrixDisplay.h"
00003 #include "matrix.h"
00004 #include <string>
00005 
00006 matrixDisplay::matrixDisplay(   float scrollRate,   PinName clockPinIn,
00007                                 PinName dataPinIn,  PinName col1,
00008                                 PinName col2,       PinName col3,
00009                                 PinName col4,       PinName col5)
00010 {
00011     clockPin = new DigitalOut(clockPinIn);
00012     dataPin = new DigitalOut(dataPinIn);
00013     columnsBus = new BusOut(col1, col2, col3, col4, col5);
00014     column = 0;
00015     whereInMessage = 0;
00016     message = NULL;
00017     // clear the text array.
00018     for (int i =0 ; i < numOfChars; i++)
00019         text[i] = ' ';
00020     loadDisplay();
00021     colTick.attach_us(this, &matrixDisplay::colChange, 5000);
00022     scroll.attach(this, &matrixDisplay::scrollMessage, scrollRate);
00023 }
00024 
00025 matrixDisplay::~matrixDisplay()
00026 {
00027     stop();
00028 }
00029 
00030 // Stop displaying stuff.
00031 void matrixDisplay::stop()
00032 {
00033     colTick.detach();
00034     scroll.detach();
00035     columnsBus->write( 0);
00036 }
00037 
00038 // load a new message
00039 // keeps a pointer to it, so bad things could happen.
00040 void matrixDisplay::setMessage(char * newMessage)
00041 {
00042     for (int i =0 ; i < numOfChars; i++)
00043         text[i] = ' ';
00044     message = newMessage;
00045     whereInMessage = 0;
00046 }
00047 
00048 void matrixDisplay::outputCol(int colNum)  // colNum is 0-4
00049 {
00050     for (int i = 0; i< numOfLeds; i++)  // once for each bool in the "display" which has already been set up
00051     {
00052         clockPin->write(1);
00053         if (display[colNum][i])
00054             dataPin->write(1);
00055         else
00056             dataPin->write(0);
00057         clockPin->write(0);
00058     }
00059 }
00060 
00061 void matrixDisplay::colChange()
00062 {
00063     columnsBus->write( 0);
00064     column ++;
00065     if (column > 4)
00066         column = 0;
00067     outputCol(column);
00068     columnsBus->write (1 << column); // columns is a bit pattern
00069 }
00070 
00071 // turns the contents of "text" into the bit pattern in "display"
00072 void matrixDisplay::loadDisplay()
00073 {
00074     for (int i =0;i < numOfChars; i ++)   // for each char in text
00075     {
00076         char c = text[i];
00077         c -= 32;    // index an array starting at 0 for char ' ' (space)
00078         for (int led = 0; led < numOfRows; led++)   // for each led in the column, done this way round because that's the way it's stored in matrix.h
00079         {
00080             int bits = char_data[c][led];
00081             for (int col = 0; col < numOfColumns; col++)   // for each column
00082             {
00083                 display[col][led+i*numOfRows] = (bits & 1<< col);
00084             }    
00085         }        
00086     }
00087 }
00088 
00089 void matrixDisplay::scrollMessage()
00090 {
00091     if (message == NULL)    // It may not have been set yet.
00092         return;
00093     if (whereInMessage >= strlen(message))
00094         whereInMessage =0;
00095     for (int i=1;i<numOfChars;i++)
00096     {
00097         text[i-1] = text[i];
00098     }
00099     text[numOfChars-1] = message[whereInMessage];
00100     loadDisplay();
00101     whereInMessage ++;
00102 }