DMD.h

/*--------------------------------------------------------------------------------------

 DMD.h   - Function and support library for the Freetronics DMD, a 512 LED matrix display
           panel arranged in a 32 x 16 layout.

 Copyright (C) 2011 Marc Alexander (info <at> freetronics <dot> com)

 Note that the DMD library uses the SPI port for the fastest, low overhead writing to the
 display. Keep an eye on conflicts if there are any other devices running from the same
 SPI port, and that the chip select on those devices is correctly set to be inactive
 when the DMD is being written to.


LED Panel Layout in RAM
                            32 pixels (4 bytes)
        top left  ----------------------------------------
                  |                                      |
         Screen 1 |        512 pixels (64 bytes)         | 16 pixels
                  |                                      |
                  ---------------------------------------- bottom right

 ---
 
 This program is free software: you can redistribute it and/or modify it under the terms
 of the version 3 GNU General Public License as published by the Free Software Foundation.

 This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with this program.
 If not, see <http://www.gnu.org/licenses/>.

--------------------------------------------------------------------------------------*/
#ifndef DMD_H_
#define DMD_H_

//Arduino toolchain header, version dependent
#if defined(ARDUINO) && ARDUINO >= 100
	#include "Arduino.h"
#else
	#include "WProgram.h"
#endif

//SPI library must be included for the SPI scanning/connection method to the DMD
#include "pins_arduino.h"
#include <avr/pgmspace.h>
#include <SPI.h>

// ######################################################################################################################
// ######################################################################################################################
#warning CHANGE THESE TO SEMI-ADJUSTABLE PIN DEFS!
//Arduino pins used for the display connection
#define PIN_DMD_nOE       9    // D9 active low Output Enable, setting this low lights all the LEDs in the selected rows. Can pwm it at very high frequency for brightness control.
#define PIN_DMD_A         6    // D6
#define PIN_DMD_B         7    // D7
#define PIN_DMD_CLK       13   // D13_SCK  is SPI Clock if SPI is used
#define PIN_DMD_SCLK      8    // D8
#define PIN_DMD_R_DATA    11   // D11_MOSI is SPI Master Out if SPI is used
//Define this chip select pin that the Ethernet W5100 IC or other SPI device uses
//if it is in use during a DMD scan request then scanDisplayBySPI() will exit without conflict! (and skip that scan)
#define PIN_OTHER_SPI_nCS 10
// ######################################################################################################################
// ######################################################################################################################

//DMD I/O pin macros
#define LIGHT_DMD_ROW_01_05_09_13()       { digitalWrite( PIN_DMD_B,  LOW ); digitalWrite( PIN_DMD_A,  LOW ); }
#define LIGHT_DMD_ROW_02_06_10_14()       { digitalWrite( PIN_DMD_B,  LOW ); digitalWrite( PIN_DMD_A, HIGH ); }
#define LIGHT_DMD_ROW_03_07_11_15()       { digitalWrite( PIN_DMD_B, HIGH ); digitalWrite( PIN_DMD_A,  LOW ); }
#define LIGHT_DMD_ROW_04_08_12_16()       { digitalWrite( PIN_DMD_B, HIGH ); digitalWrite( PIN_DMD_A, HIGH ); }
#define LATCH_DMD_SHIFT_REG_TO_OUTPUT()   { digitalWrite( PIN_DMD_SCLK, HIGH ); digitalWrite( PIN_DMD_SCLK,  LOW ); }
#define OE_DMD_ROWS_OFF()                 { digitalWrite( PIN_DMD_nOE, LOW  ); }
#define OE_DMD_ROWS_ON()                  { digitalWrite( PIN_DMD_nOE, HIGH ); }

//Pixel/graphics writing modes (bGraphicsMode)
#define GRAPHICS_NORMAL    0
#define GRAPHICS_INVERSE   1
#define GRAPHICS_TOGGLE    2
#define GRAPHICS_OR        3
#define GRAPHICS_NOR       4

//drawTestPattern Patterns
#define PATTERN_ALT_0     0
#define PATTERN_ALT_1     1
#define PATTERN_STRIPE_0  2
#define PATTERN_STRIPE_1  3

//display screen (and subscreen) sizing
#define DMD_PIXELS_ACROSS         32      //pixels across x axis (base 2 size expected)
#define DMD_PIXELS_DOWN           16      //pixels down y axis
#define DMD_BITSPERPIXEL           1      //1 bit per pixel, use more bits to allow for pwm screen brightness control
#define DMD_RAM_SIZE_BYTES        ((DMD_PIXELS_ACROSS*DMD_BITSPERPIXEL/8)*DMD_PIXELS_DOWN)
                                  // (32x * 1 / 8) = 4 bytes, * 16y = 64 bytes per screen here.
//lookup table for DMD::writePixel to make the pixel indexing routine faster
static byte bPixelLookupTable[8] =
{
   0x80,   //0, bit 7
   0x40,   //1, bit 6
   0x20,   //2. bit 5
   0x10,   //3, bit 4
   0x08,   //4, bit 3
   0x04,   //5, bit 2
   0x02,   //6, bit 1
   0x01    //7, bit 0
};

// Font Indices
#define FONT_LENGTH             0
#define FONT_FIXED_WIDTH        2
#define FONT_HEIGHT             3
#define FONT_FIRST_CHAR         4
#define FONT_CHAR_COUNT         5
#define FONT_WIDTH_TABLE        6

typedef uint8_t (*FontCallback)(const uint8_t*);


//The main class of DMD library functions
class DMD
{
  public:
    //Instantiate the DMD
    DMD(byte panelsWide, byte panelsHigh);
	//virtual ~DMD();

  //Set or clear a pixel at the x and y location (0,0 is the top left corner)
  void writePixel( unsigned int bX, unsigned int bY, byte bGraphicsMode, byte bPixel );

  //Draw a string
  void drawString( int bX, int bY, const char* bChars, byte length, byte bGraphicsMode);

  //Select a text font
  void selectFont(const uint8_t* font);

  //Draw a single character
  int drawChar(const int bX, const int bY, const unsigned char letter, byte bGraphicsMode);

  //Find the width of a character
  int charWidth(const unsigned char letter);

  //Draw a scrolling string
  void drawMarquee( const char* bChars, byte length, int left, int top);

  //Move the maquee accross by amount
  boolean stepMarquee( int amountX, int amountY);

  //Clear the screen in DMD RAM
  void clearScreen( byte bNormal );

  //Draw or clear a line from x1,y1 to x2,y2
  void drawLine( int x1, int y1, int x2, int y2, byte bGraphicsMode );

  //Draw or clear a circle of radius r at x,y centre
  void drawCircle( int xCenter, int yCenter, int radius, byte bGraphicsMode );

  //Draw or clear a box(rectangle) with a single pixel border
  void drawBox( int x1, int y1, int x2, int y2, byte bGraphicsMode );

  //Draw or clear a filled box(rectangle) with a single pixel border
  void drawFilledBox( int x1, int y1, int x2, int y2, byte bGraphicsMode );

  //Draw the selected test pattern
  void drawTestPattern( byte bPattern );

  //Scan the dot matrix LED panel display, from the RAM mirror out to the display hardware.
  //Call 4 times to scan the whole display which is made up of 4 interleaved rows within the 16 total rows.
  //Insert the calls to this function into the main loop for the highest call rate, or from a timer interrupt
  void scanDisplayBySPI();


  private:
    void drawCircleSub( int cx, int cy, int x, int y, byte bGraphicsMode );

    //Mirror of DMD pixels in RAM, ready to be clocked out by the main loop or high speed timer calls
    byte *bDMDScreenRAM;

    //Marquee values
    char marqueeText[256];
    byte marqueeLength;
    int marqueeWidth;
    int marqueeHeight;
    int marqueeOffsetX;
    int marqueeOffsetY;

    //Pointer to current font
    const uint8_t* Font;

    //Display information
    byte DisplaysWide;
    byte DisplaysHigh;
    byte DisplaysTotal;
    int row1, row2, row3;

    //scanning pointer into bDMDScreenRAM, setup init @ 48 for the first valid scan
    volatile byte bDMDByte;

};

#endif /* DMD_H_ */