/***************************************************************************************/
/* Analog.c    Example of PIC16F8xx Analog to Digital Converter                        */
/*                                                                                     */
/* By: J.Winpenny                                                                      */
/*-------------------------------------------------------------------------------------*/
/*   Date:      |      Revision History                                                */
/*-------------------------------------------------------------------------------------*/
/*  07/02/2000  |  Initial coding.                                                     */
/*              |                                                                      */
/*              |                                                                      */
/*              |                                                                      */
/*              |                                                                      */
/*              |                                                                      */
/*              |                                                                      */
/*              |                                                                      */
/*-------------------------------------------------------------------------------------*/
/*                                                                                     */
/*  Simple Test of A/D single channel Input.                                           */
/*  Reads the A/D converter and displays the result.                                   */
/*                                                                                     */
/*                                                                                     */
/*                                                                                     */
/*                                                                                     */
/*                                                                                     */
/***************************************************************************************/

#include <LCD.h>   // Definitions of lcd.c 



#pragma CLOCK_FREQ 3579545  // Processor clock frequency in Hz.
                            // Default value for PIC is 4000000 (4MHz)
                            // and for SX 50000000 (50MHz).


// PORT Configuration
#define PortAConfig 0x00
#define PortBConfig 0xf0
#define PortCConfig 0x98 /* SCL & SDA as Inputs */
#define PortDConfig 0x00
#define PortEConfig 0x00


// USART Register bits
#define CSCR 7
#define TX9  6
#define TXEN 5
#define SYNC 4
#define BRGH 2
#define TRMT 1
#define TX9D 0
#define SPEN 7
#define RX9  6
#define SREN 5
#define CREN 4
#define ADDEN 3
#define FERR 2
#define OERR 1
#define RX9D 0

#define TRMT_MASK 2

// Masks for PIR1
#define PSPIF_MASK 0x80
#define ADIF_MASK  0x40
#define RCIF_MASK  0x20
#define TXIF_MASK  0x10


// Registers for I2C
char SSPSTAT@0x94;  // Bank 1
char SSPCON@0x14;   // Bank 0
char SSPCON2@0x91;  // Bank 1
char SSPBUF@0x13;   // I2C Buffer
char SSPADD@0x93;   // I2C Slave Address register

// Bits of SSPSTAT
#define SMP 7
#define CKE 6
#define D_A 5
#define P   4
#define S   3
#define R_W 2
#define R_W_MASK 0x04
#define UA  1
#define BF  0

// Bits of SSPCON2

#define GCEN    7
#define ACKSTAT 6
#define ACKDT   5
#define ACKEN   4
#define RCEN    3
#define PEN     2
#define RSEN    1
#define SEN     0


// Bits of PIR1
#define PSPIF  7
#define ADIF   6
#define RCIF   5
#define TXIF   4
#define SSPIF  3
#define SSPIF_MASK 0x08
#define CCP1IF 2
#define TMR2IF 1
#define TMR1IF 0

// Bits of SSPCON

#define WCOL  7
#define SSPOV 6
#define SSPEN 5
#define CKP   4
#define SSPM3 3
#define SSPM2 2
#define SSPM1 1
#define SSPM0 0

// Bits of ADCON0
#define GO_DONE 2
#define GO_DONE_MASK 0x04

// Bits of PIE1
#define ADIE 6


// Port addresses
char PORTC@0x07;
char PORTD@0x08;
char PORTE@0x09;

// USART Registers
char TXREG@0x19;
char RCREG@0x1a;
char TXSTA@0x98;
char RCSTA@0x18;
char SPBRG@0x99;

// Extra Ports on PIC16F877
char TRISC@0x87;
char TRISD@0x88;
char TRISE@0x89;

char PIE1@0x8c;
char PIE2@0x8d;

char PIR1@0x0c;
char PIR2@0x0d;
char PCON@0x8e;

// ADC registers;
char ADCON0@0x1f;
char ADCON1@0x9f;
char ADRESH@0x1e;
char ADRESL@0x9e;


void Setup(void);
void UpdateAnalog(void);
void ShowAsHex( char bcd );


char ADH; // Storage of A/D converter result ( high byte )
char ADL; // Storage of A/D converter result (  low byte )


const char *Message1 = "Analog Display";

void interrupt(void)
{

   if ( PIR1 & ADIF_MASK  )         // If the A/D interrupted
      {
         UpdateAnalog();            // Update the A/D value for display
         clear_wdt();
         clear_bit( PIR1, ADIF );   // Clear the interrupt flag
      }

// Return from Interrupt
}


void main( void)
{


   Setup(); // Setup the Ports etc.

   /*****************************/
   /* Display a startup message */
   /*****************************/   
   
   WriteLCDString( Message1 );

   /*********************************/
   /* Constantly display A/D result */
   /*********************************/   
   
         while(1)
         {
   
   
           LCD_Line_2();
           WriteLCDString("A/D = ");
          
           /**********************/
           /* Start converting.  */
           /**********************/
           
           clear_bit( PIR1, ADIF );
           set_bit( ADCON0, GO_DONE );
 

           /**********************/
           /* Display result     */
           /**********************/
           
           ShowAsHex( ADH );
           ShowAsHex( ADL );   
           
           
           delay_ms(5);
   
         }



}



/*****************************************************/
/* setup PIC16F877 options,ports,interrupts          */
/*****************************************************/
void Setup(void)
{

  set_bit( INTCON, GIE );            // Enable Global Interrupts
  set_bit( INTCON, PEIE );                                             // Enable all Peripheral Interrupts

  set_bit( PIE1, ADIE );             // Enable A/D interrupt

  OPTION_REG = 0x0E;                 // Set Option register
                                     // Prescaler = WDT
                                     // 0x0C = WDT rate := 1:16
                                     // 0x0E = WDT rate := 1:64

  TRISD = PortDConfig;

//  ADCON1 = 0x7f;                   // Disable ADC
    ADCON1 = 0x82;                   // Enable ADC

  //PCON = 0x03;                     // Reset Power up status flags

  TRISA = PortAConfig;
  TRISB = PortBConfig;
  TRISC = PortCConfig;
  TRISE = PortEConfig;

                                     // Select an A/D input channel 
  ADCON0 = 0x41;                     // A/D converter enabled
                                     // Upper 2 bits affect conversion speed. 

  PIR1 = 0;

  clear_wdt();

  LCD_Setup();                       // Setup the LCD 


}


/***************************/
/* ADIF Interrupt routine  */
/***************************/
void UpdateAnalog(void)
{
 
 /* Other processing here */
 
   ADH = ADRESH; 
   ADL = ADRESL;

}

/******************************************/
/* Convert the char to HEX and display    */
/******************************************/
void ShowAsHex( char bcd )
{
 
char n;
 
  n = bcd;
  n >>= 4;   // Do high nibble first
  n &= 0x0f; // Mask upper bits  

  if ( n < 10 ) LCD_Write_4_Bit( n + '0' );
  else LCD_Write_4_Bit( ( n-10 ) + 'A' );
  
  bcd &= 0x0f; // Mask upper bits for low nibble
  
  if ( bcd < 10 ) LCD_Write_4_Bit( bcd +'0' );
  else LCD_Write_4_Bit( ( bcd-10 ) + 'A' );

}


/*********************************************/
/* Include code for the lcd interface        */
/*********************************************/
#include <Lcd.c>