/************************************************************************/
/*                                                                      */
/*			7 Segment Driver MAX7219			*/
/*			Common Anode Display				*/
/*                                                                      */
/*              Author: Peter Dannegger                                 */
/*                      danni@specs.de                                  */
/*                                                                      */
/************************************************************************/

#include "main.h"
#include "max7219.h"

u8 brightness = 5;

u8 code digits[] = { DIGITS };

u8 displaymem[8] = { CHAR_SPACE,	// 8 digits, msb first
		     CHAR_SPACE,
		     CHAR_SPACE,
		     CHAR_SPACE,
		     CHAR_SPACE,
		     CHAR_SPACE,
		     CHAR_SPACE,
		     CHAR_SPACE };

u8 code charset[] = {		// Definition Character Set
	_A+_B+_C+_D+_E+_F   ,		// CHAR_0
	   _B+_C	    ,		// CHAR_1
	_A+_B+   _D+_E+   _G,		// CHAR_2
	_A+_B+_C+_D+      _G,		// CHAR_3
	   _B+_C+      _F+_G,		// CHAR_4
	_A+   _C+_D+   _F+_G,		// CHAR_5
	_A+   _C+_D+_E+_F+_G,		// CHAR_6
	_A+_B+_C            ,		// CHAR_7
	_A+_B+_C+_D+_E+_F+_G,		// CHAR_8
	_A+_B+_C+_D   +_F+_G,		// CHAR_9
	_A+_B+_C+   _E+_F+_G,		// CHAR_A
	      _C+_D+_E+_F+_G,		// CHAR_b
		 _D+_E+   _G,		// CHAR_c	;'c'
	   _B+_C+_D+_E+   _G,		// CHAR_d
	_A+      _D+_E+_F+_G,		// CHAR_E
	_A+         _E+_F+_G,		// CHAR_F
	0                   ,		// 16 = SPACE
			  _G,		// 17 = MINUS
	_A+_B+         _F+_G,		// 18 = GRAD
	_A+      _D+_E+_F   ,		// 19 = CHAR_C2	;'C'
		    _E+   _G,		// 20 = CHAR_r
	      _C+_D+_E+   _G,		// 21 = CHAR_o
	   _B+_C+   _E+_F+_G,		// 22 = H
		 _D+_E+_F   ,		// 23 = L
		 _D	    ,		// 24 = _
	_A		    ,		// 25 = upper "-"
	_A+_B+      _E+_F+_G,		// CHAR_P
	   _B+_C+_D+_E+_F   ,		// CHAR_U
	_A+_B+_C+   _E+_F   		// CHAR_M
	};


void display_write( u16 dc )
{
  u8 i;

  MAX7219_DDR |= 1<<MAX7219_DO;
  MAX7219_DDR |= 1<<MAX7219_SCK;
  MAX7219_DDR |= 1<<MAX7219_STB;
  MAX7219_PORT &= ~(1<<MAX7219_STB);

  for( i = 12; i; i-- ){
    MAX7219_PORT &= ~(1<<MAX7219_SCK);
    MAX7219_PORT |= 1<<MAX7219_DO;
    if( (dc & 0x0800) == 0 )
      MAX7219_PORT &= ~(1<<MAX7219_DO);
    dc <<= 1;
    MAX7219_PORT |= 1<<MAX7219_SCK;
  }

  MAX7219_PORT |= 1<<MAX7219_STB;
}


void display_out( void )
{
  u8 * dptr;
  u8 i, j, byte;

  display_write( 0xC01 );

  dptr = displaymem;
  for( i = 8; i; i-- ){
    j = LPM(charset + (*dptr & 0x3F));		// convert to 7-segment
    if( *dptr & 0x80 )
      j |= _DP;					// set decimal point
    *dptr++ = j;
  }

  for( i = 8; i; i-- ){				// for all segments
    dptr = displaymem;
    byte = 0;
    for( j = 8; j; j-- ){			// collect all digits
      if( *dptr & 1 )
        byte |= LPM(digits+j-1);		// digit order mask
      *dptr >>= 1;				// next segment
      dptr++;
    }
    display_write( byte + i * 256);		// output same segments
  }
}


void display_clear( void )
{
  u8 i;

  for( i = 8; i; i--)
    displaymem[i-1] = CHAR_SPACE;
}


void display_init( void )
{
  display_write( 0xF00 );		// Testmode off
  display_write( 0x900 );		// Decode off
  display_write( 0xB07 );		// 8 Digits
  display_write( 0xC01 );		// Display on
  display_write( 0xA00 | brightness );	// Brightness
}


void display_off( void )
{
  display_write( 0xC00 );
}