#include <reg51.h>
#include "io.h"

/*==========================================================================
 *                                  delay()
 *--------------------------------------------------------------------------
 * Delay function.
 *========================================================================*/
void delay(){
  int i, j;        
  /*++++++*/
  for(i=0; i<500; i++)
    for(j=0; j<10; j++)                        
      i = i + 0;
  return;
}
/*==========================================================================
 *                           hello()
 *--------------------------------------------------------------------------
 * Just to say hello...
 *========================================================================*/
void
hello( void )
{
  unsigned char loops;
  unsigned char counter;
  /*++++++++++++++++++*/
  /* Just to show we're alive */
#if 0
  for( counter = 0; counter < 0xff ; counter++){
    P2 = 0xff ^ counter;
    delay();
  }
#else
  for( loops = 3; loops ; loops--){
    for( counter = 1; counter; counter <<= 1){
      P2 = 0xff ^ counter;
      delay();
    }
  }
#endif
  return;
}
/*==========================================================================
 *                                  main()
 *--------------------------------------------------------------------------
 * Delay function.
 *========================================================================*/
sbit READ = P3^2; /* Define these according to how you have connected the */
sbit WRITE = P3^3;/* RD, WR, and INTR pins                                */ 
sbit INTR = P3^4;
sbit BEEP5 = P3^5;
sbit BEEP6 = P3^6;
sbit BEEP7 = P3^7;
	
void main( void ) {
  unsigned char adVal;	
  unsigned char counter1, counter2;
  unsigned minmaxVal = 0xff;
  unsigned maxVal;
  unsigned uptime = 0, downtime = 0, olddowntime = 0, direction = 0;
  unsigned i;
  /*+++++++++++++++*/
  BEEP5 = 0;
  BEEP6 = 0;
  BEEP7 = 0;

  hello();

  READ = 1;
  WRITE = 1;
  INTR = 1;

  for( counter1 = 0; ; counter1++){
    for( counter2 = 0; ; counter2++){
      /*================================================
       * We determine the current signal state here.
       *==============================================*/
      /* Make a low-to-high transition on the WR input */
      WRITE=0;
      WRITE=1;
      /* wait until the INTR signal makes  */
      /* high-to-low transition indicating */
      /* completion of conversion          */
      while( INTR == 1);

      /*  Read the voltage value from the port */              
      READ = 0;
      adVal = P1;
      READ = 1;

      /*================================================
       * We process the current signal state here.
       *==============================================*/
      /* Seek the local maximum */
      if( adVal > maxVal)
        maxVal = adVal;

      /* Determine what to do with the peak local reading: */ 
      if( ! counter1 && ! counter2){
        if( maxVal < minmaxVal) /* Currently not used. */
          minmaxVal = maxVal;

        /* Display current local max */
        P2 = 0xFF ^ maxVal;

       /* We do our sound level duration counting here */
       if( maxVal >= 0x40 ){
         if( direction == 0){ /* Switched intensity states? */
           direction = 1;
           uptime = 1;
         }
         else
           ++uptime;
       }
       else{
         if( direction == 1){ /* Switched intensity states? */
           direction = 0;
           olddowntime = downtime;
           downtime = 1;
         }
         else
           ++downtime;
       }
 
       /* Do we have a irritating "dog"? */
       if(  direction == 0
         && olddowntime > 20
         && downtime == 3  /* Only fire at this point */
         && uptime > 2
         && uptime < 10
       ){
         BEEP5 = 1;
         BEEP6 = 1;
         BEEP7 = 1;
         for( i = 0; i < 20; i++){ /* Bad dog! */
           delay();
         }
         BEEP5 = 0;
         BEEP6 = 0;
         BEEP7 = 0;
       }

        /* We count on the roll over to "reset". */
        maxVal = 0;
      }
    }
  }
}