Speaker

/* *****************************************************************************
;                                                                             *
;    Filename:                     				                              *
;    Date:                                         	                          *
;    File Version: 001                                                        *
;                                                                             *
;    Author:   Jason Lopez                                                    *
;    Company:  AtomSoft                                                       *
;                                                                             *
;***************************************************************************** */

#include <p18f248.h>
#include <delays.h>

#define SPK LATB
#define DWN PORTCbits.RC3
#define UP PORTCbits.RC2
#pragma config WDT = OFF, LVP = OFF, OSC = HS,OSCS = OFF


/************************************
Prototypes
*************************************/
void main(void);
void CheckBtn(void);

unsigned char Speed = 2;
/************************************
Main - 20MHZ OSC
*************************************/
void main(void){
    
	ADCON1 = 0x0F;			//Digital Pins (we dont need ADC)

	TRISB = 0x00;	//All Outputs
	LATB = 0x00;		//All Low

    TRISC = 0b00001100;
    
	while(1){
        SPK = 0xff;
        Delay100TCYx(Speed);
        CheckBtn();

        SPK = 0;
        Delay100TCYx(Speed);
        CheckBtn();
	}
}
void CheckBtn(void)
{
    if(UP)
    {
        Delay10KTCYx(50);//100ms
        if(Speed < 255)
        {
            Speed++;
        }
    }
    if(DWN)
    {
        Delay10KTCYx(50);//100ms
        if(Speed > 0)
        {
            Speed--;
        }
    }


}

/********************************************************************
 *  NCO (numerically controlled oscillator) ouput range 1..5000 Hz  *
 *  use 8388608-Hz crystal and 4xPLL with speaker connected to RB2  *
 ********************************************************************/
#include <system.h>

unsigned long accum;            // 24-bit phase accumulator
unsigned long phase;            // 24-bit phase offset (tuning word)

//--< isr >----------------------------------------------------------

void interrupt()                // 200-cycles (41943.04-Hz)
{ pir1.TMR2IF = 0;              // clear TMR2 interrupt flag
  accum += phase;               // add phase offset to accum
  latb.2 = accum.23;            // square wave output
}

//--< main >---------------------------------------------------------

void main()
{
  trisb = 0;                    //
  latb = 0;                     //
//
// this is how you set tone output frequency
//
  phase = 25410<<2;             // phase offset for 254.10-Hz tone

  while(1)                      // loop forever
  {                             //
  }                             //
}