#include<C51RB2.h>
#include<stdio.h>
#include<string.h>
#include <stdlib.h>

#define	XTAL		11.0592e6 //11Mhz Quarz

#define	xRC5_IN		P0
#define	xRC5		7			// IR input low active

#define RC5TIME 	1.778e-3		// 1.778msec
#define PULSE_MIN	(unsigned char)(XTAL / 512 * RC5TIME * 0.4 + 0.5)
#define PULSE_1_2	(unsigned char)(XTAL / 512 * RC5TIME * 0.8 + 0.5)
#define PULSE_MAX	(unsigned char)(XTAL / 512 * RC5TIME * 1.2 + 0.5)



unsigned char	rc5_bit;				// bit value
unsigned char	rc5_time;				// count bit time
unsigned int	rc5_tmp;				// shift bits in
unsigned int	rc5_data;				// store result
unsigned int left;
unsigned int left2;


 void uart_init(void)
 {
 // Baudrate = 19200
 SCON = 0x50;  // 8 Bit UART 
 REN = 1; //Recieve Interrupt Enable
 IEN0 =0x10; //enable Uart interrupt
 TH1=0xFD;       
 PCON |=0x80;
 TMOD |=0x21;  // use timer 1 as baudrate generator
 TCON |=0x40;   
 ES=0;    // UART Interrupt deaktivieren
 EA= 1;    // Interrupts generell aktivieren
 TI = 0;
 }
 
  void init_timer0(void)
 {

 //Interrupt alle 0,18ms
 TMOD = 0x2; //8bit 
 //TCON = 0x16;
 TH0 = 0xA6; //Timer 0 High Byte setzen
 TL0 = 0xA6; //Timer 0 Low Byte setzen
 ET0 = 1; //Timer 0 Interrupt aktivieren
 TR0 = 1; //Timer 0 am Anfang aktivieren
 
 }

void IR_Timer(void) interrupt 1 using 1
{

unsigned tmp = rc5_data;



  if( ++rc5_time > PULSE_MAX ){			// count pulse time
    if( !(tmp & 0x4000) && tmp & 0x2000 )	// only if 14 bits received
      rc5_data = tmp;
    tmp = 0;
  }
  
  left = xRC5;
  if( (rc5_bit ^ xRC5_IN) & 1<<left ){		// change detect
    rc5_bit = ~rc5_bit;				// 0x00 -> 0xFF -> 0x00

    if( rc5_time < PULSE_MIN )			// to short
      tmp = 0;

    if( !tmp || rc5_time > PULSE_1_2 ){		// start or long pulse time
      if( !(tmp & 0x4000) )			// not to many bits
        tmp <<= 1;				// shift
      left2 = xRC5;
      if( !(rc5_bit & 1<<left2) )		// inverted bit
        tmp |= 1;				// insert new bit
      rc5_time = 0;				// count next pulse time
    }
  }
  
  
  TF0 = 0; //Interrupt Flag loeschen
  
}

void putchar_new (char c)  
{
  TI = 0;                 // TI Flag löschen
  SBUF = c;               // Ausgabe an UART
  while (TI == 0);       // Transmitter ready/busy ?
  
}

void puts_new( char *s )
{
  while( *s )
    putchar_new( *s++ );
    
}

void main(void)

{
 
  unsigned int i;
  char s[30];
 
 
 init_timer0();
 uart_init();
 
 puts_new("Dekodierung des RC5 Codes");
 
 for(;;)
 {
   EA = 0; //entspricht cli(); 
   i = rc5_data;
   rc5_data = 0;
   EA = 1; //entspricht sei(); 
   if(i)
   {
     puts_new("Test");
     putchar_new(( i >> 11 & 1) + '0');	// Toggle Bit
     putchar_new(' ');
     sprintf(s,"%d",i >> 6 & 0x1F); //entspricht itoa( i >> 6 & 0x1F, s, 10);
     puts_new( s );
     putchar_new(' ');
     sprintf(s,"%d",(i & 0x3F) | (~i >> 7 & 0x40)); //entspricht itoa((i & 0x3F) | (~i >> 7 & 0x40), s, 10); // Key Code
     puts_new( s );
     puts_new( "\n\r" );
   }
  }
  
}