LEDMatrix.h

00001 #include "mbed.h"
00002 #include "Matrix.h"
00003 
00004 template <int WIDTH, int HEIGHT> class LEDMatrix : public Matrix<bool> {
00005   private:
00006     //Array of row pins
00007     DigitalOut* _rows;
00008     
00009     //Pointers to column control pins
00010     DigitalOut* _nextCol;
00011     DigitalOut* _firstCol;
00012     int _usPerColumn;
00013     
00014   public:
00015     LEDMatrix(DigitalOut rows[HEIGHT], DigitalOut* nextCol, DigitalOut* firstCol, int usPerFrame) : Matrix<bool>(WIDTH, HEIGHT), _rows(rows), _nextCol(nextCol), _firstCol(firstCol) { 
00016         clear();
00017         _usPerColumn = usPerFrame / WIDTH;
00018     }
00019     
00020     void redraw() {
00021         //Pulse firstCol
00022         *_firstCol = 1;
00023         wait_us(10);
00024         *_firstCol = 0;
00025         
00026         //Account for reverse column ordering
00027         for (int col = WIDTH - 1; col >= 0; col--) {
00028             //Pulse nextCol
00029             *_nextCol = 1;
00030             wait_us(10);
00031             *_nextCol = 0;
00032             
00033             //Output a column of data to the row pins.
00034             for(int row = 0; row < HEIGHT; row++) {
00035                 _rows[row] = (*this)(col, row);
00036             }
00037             
00038             //Wait
00039             wait_us(_usPerColumn);
00040             
00041             //Clear the column, ready for the next iteration
00042             for(int i = 0; i < HEIGHT; i++) {
00043                 _rows[i] = false;
00044             }
00045         }
00046     }
00047 };