/* Arlotto 2005 : fonctions ds1621 */
#include <pic.h>
#include <stdio.h>
#include <string.h>
#include "biosdem.h"

#define DS1621_W 0x92
#define DS1621_R 0x93
#define ACCESS_CONFIG 0xAC 
#define READ_TEMP 0xAA
#define START_CONVERT 0xEE
void i2c_init(void)  {
    char x ;
    TRISC3 = 1 ; //SDA et SCL en entrée
    TRISC4 = 1 ;
    SSPSTAT = 0x80 ; // Pas de controle de slew rate, niveaux i2c
    SSPCON = 0x28 ; // enable i2c 7bits master mode
    SSPADD =  9 ; // fclock = 100khz = Fosc/(4(SSPADD+1)
    x = SSPBUF ; // vide le buffer et raz flags
   }
   
void init_ds1621(void)
{
 	SEN = 1;					
	while(SEN);					
   	SSPIF = 0;
    
	SSPBUF = DS1621_W ;
	while(!SSPIF);	
	  
	SSPIF = 0;					
    SSPBUF = ACCESS_CONFIG ;
	while(!SSPIF);
				
	SSPIF = 0;								
    SSPBUF = 0x08;   // 1SHOT = 0 ;      
	while(!SSPIF);		  // Attention POL et 1SHOT non volatile	

	SSPIF = 0;	
    PEN = 1;					
	while(PEN);							
    DelayMs(10);         // attend fin écriture EEPROM

    SEN = 1;					
	while(SEN);					
   	SSPIF = 0;
    
	SSPBUF = DS1621_W ;
	while(!SSPIF);	
	  
	SSPIF = 0;					
    SSPBUF = START_CONVERT ;
	while(!SSPIF);
    PEN = 1;					
	while(PEN);	
  
  		
}
unsigned char read_config(void)
{
    unsigned char config ;
  	SEN = 1;					
	while(SEN);	
				
   	SSPIF = 0;
	SSPBUF = DS1621_W ;
	while(!SSPIF);	
	  
	SSPIF = 0;					
    SSPBUF = ACCESS_CONFIG ;
	while(!SSPIF); 

    RSEN = 1;				
	while(RSEN);
    
   	SSPIF = 0;
	SSPBUF = DS1621_R ;
	while(!SSPIF);	

     RCEN = 1;					
	while(!STAT_BF);			
	config = SSPBUF;
    
     ACKDT=1;		     	
	ACKEN = 1;					
	while(ACKEN);
	 
	PEN = 1;					
	while(PEN);	

    return config ;
}

int read_temp(void)
{ 
    char th,tb;

    SEN = 1;					
	while(SEN);
					
   	SSPIF = 0;
	SSPBUF = DS1621_W ;
	while(!SSPIF);	
		  
	SSPIF = 0;					
    SSPBUF = READ_TEMP ;
	while(!SSPIF);
 
    RSEN = 1;				
	while(RSEN);
    
   	SSPIF = 0;
	SSPBUF = DS1621_R ;
	while(!SSPIF);	

    RCEN = 1;					
	while(!STAT_BF);			
	th = SSPBUF;


    ACKDT=0;		     	
	ACKEN = 1;					
	while(ACKEN);

    RCEN = 1;					
	while(!STAT_BF);			
	tb = SSPBUF;

    ACKDT=1;		     	
	ACKEN = 1;					
	while(ACKEN);	 
	PEN = 1;					
	while(PEN);	
    return (th<<8)+tb;		
}