#include	<pic.h>
#include  <conio.h>
#include  <stdio.h>

#include "i2cmsu.h"


#define DATA_EEMEM_PROTECT_DISABLE 0x0100
#define XT_OSC 0x0001
#define DISABLE_DEBUG 0x0800

#define CP0		0x1010
#define CP1		0x2020

/* CP0,CP1  code protect off*/
/* other bits zero which means WDT disabled
  Low Voltage prm disabled, brownout disabled
  power up timer enabled */

__CONFIG((CP1 | CP0) | DATA_EEMEM_PROTECT_DISABLE  | XT_OSC | DISABLE_DEBUG);



#define bitset(var,bitno) ((var) |= (1 << (bitno)))
#define bitclr(var,bitno) ((var) &= ~(1 << (bitno)))
#define bittst(var,bitno) (var & (1 << (bitno)))

/* read value from ADC, output to serial port via printf */
/* also output to DAC on I2C Bus */

#define DAC 0x58        /* I2C DAC 01011000 */

/* the outer legs of the 10K pot should be hooked up between +5 and 0 */
/* the middle leg (wiper) connected to AN0 */


/* return 8 bit char from Recieve port */
char getch ()
{
  unsigned char c;

  /* while (!RCIF) */
  while (!bittst(PIR1,5));  /* check RCIF bit */
	 
  c = RCREG;
  return(c);
}

/* send 8 bit char to Recieve port */
void putch (c)
  char c;

{
  /* wait until transmit reg empty */
  /* while (!TXIF) */
  while (!bittst(PIR1,4));  /* check RCIF bit */
  TXREG = c;
}

     
void pcrlf ()
{
  putch(0x0a);
  putch(0x0d);
}

int update_dac(unsigned char val) {

  i2c_WriteTo(DAC);
  i2c_PutByte(0x00);
  i2c_PutByte(val);
  i2c_Stop();
}


main(void)
{
  int adc_value;
  char dac_value;
  char inchar;



  /* set baud rate */

  
  /* setup Async communication */
  bitclr(TXSTA, 6); /* 8-bit transmit */
  bitset(TXSTA, 5); /* transmit enable*/
  bitclr(TXSTA, 4); /* async mode */
  bitset(TXSTA, 2); /* high speed mode */

  SPBRG = 95;  /* 9600 in high baud rate mode, crystal = 14.7456 Mhz */

  bitset(TRISC, 7); /* serial port enable */
  bitset(TRISC, 6); /* serial port enable */
  bitset(RCSTA, 7); /* serial port enable */
  bitclr(RCSTA, 6); /* 8-bit reception */
  /* set baud rate */

  bitset(RCSTA, 4); /* enable recieve */
  

  /* A/D Setup */
  TRISA = 0xFF;		/* all bits input */
  ADCON1 = 0x8E;         /* A0 analog input, others digital,right justification of result */
  ADCON0 = 0x80;  /* sampling freq = Fsoc/32, channel 0 */
  bitset(ADCON0,0); /* turn on ADC*/

  printf("ADC is configured!!!");
  pcrlf();
  /* enable I2C */
  
  SSPCON = 0x28;  //Master mode

  SSPADD = 8;  // about 400Khz  for 14.7456 Mhz, verified to work

  //bitset(SSPSTAT,7); //disable slew rate control for 100 Khz
  bitset(SSPCON,5);  //SSPEN = 1;
  bitset(SSPCON,4);  //CKP = 1;
  bitset(TRISC,3);
  bitset(TRISC,4);  // SDA, SCL pins are inputs

  printf("Hit any key to start ");
  pcrlf();
  inchar=getch();

  for(;;) {

    bitset(ADCON0, 2); /* start conversion */
    while (bittst(ADCON0,2));  /* wait for end of conversion */

    /* read result */
    adc_value = 0;
    adc_value = adc_value | (ADRESH << 8);
    adc_value = adc_value | (ADRESL);
    printf("%x",adc_value);
    pcrlf();
    dac_value = ((adc_value >> 2)) & 0x00ff;
    /* now write to DAC */
   update_dac(dac_value);
    
  }

}





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