Eric Wieser / LEDMatrix

A library to manipulate 2D arrays, and output them to an LED Dot Matrix Display. The display must be wired up using a shift register combined with a nor latch.

LEDMatrix.h

Committer:
EricWieser
Date:
2012-02-13
Revision:
0:1deae5ffe9ed
Child:
1:44819562ea31

File content as of revision 0:1deae5ffe9ed:

#include "mbed.h"
#include "Locations.h"
#include "Matrix.h"

template <int WIDTH, int HEIGHT> class LEDMatrix : public Matrix<bool> {
  private:
    DigitalOut*  _rows;
    DigitalOut* _colClk;
    DigitalOut* _colReset;
    int _usPerColumn;
    
    //Column control
    void firstColumn() {
        *_colReset = 1;
        wait_us(10);
        *_colReset = 0;
    }
    void nextColumn() {
        *_colClk = 1;
        wait_us(10);
        *_colClk = 0;
    }
    void showColumn(int c) {
        bool* col = column(WIDTH - 1 - c);
        for(int i = 0; i < HEIGHT; i++) {
            _rows[i] = col[HEIGHT - 1 - i];
        }
        delete [] col;
    }
    void hideColumn(int c) {
        for(int i = 0; i < HEIGHT; i++) {
            _rows[i] = false;
        }
    }
  public:
    LEDMatrix(DigitalOut rows[HEIGHT], DigitalOut* colClk, DigitalOut* colReset, int usPerFrame) : 
      Matrix<bool>(WIDTH, HEIGHT), _rows(rows), _colClk(colClk), _colReset(colReset) { 
        clear();
        firstColumn();
        _usPerColumn = usPerFrame / WIDTH;
    }
    
    void redraw() {
        firstColumn();
        for (int col = 0; col < WIDTH; col++) {
            nextColumn();
            showColumn(col);
            wait_us(_usPerColumn);
            hideColumn(col);
        }
    }
};