//******************************************************************************************
//  PIC12F1822 Sample Program
//   Project      :
//   Program Name :
//   Programer    :
//   Create date  :  
//   History      :
//   Laungage     :  XC8 C Laungage Version 2.31
//******************************************************************************************
//   Description
//******************************************************************************************
//
#include <xc.h>
//
#pragma config FOSC     = INTOSC
#pragma config WDTE     = OFF
#pragma config PWRTE    = OFF 
#pragma config MCLRE    = OFF
#pragma config CP       = OFF
#pragma config CPD      = OFF
#pragma config BOREN    = OFF 
#pragma config CLKOUTEN = OFF
#pragma config IESO     = OFF
#pragma config FCMEN    = OFF
//
#pragma config WRT    = OFF
#pragma config PLLEN  = OFF
#pragma config STVREN = OFF 
#pragma config BORV   = HI 
#pragma config LVP    = OFF 

void Wait_01nmS(unsigned int);
void Wait_01mS(void)         ;
void Init_adc(void)           ;
unsigned int Get_adc(void)    ;

void main()
{
    unsigned int lp = 0;
    unsigned int adc_data;
    unsigned int adc_data_L;
    unsigned int adc_data_H;
       
// *****************************
//   1.Initialized 
// *****************************
// (1)Define OSC (16MHz, IntOSC)
    OSCCON = 0b01111010;    // 16MHz,    IntOSC

// (2)Define ANSELA Register
    ANSELA |= 0b00000001;
    
// (3)Initialized A/D converter
    Init_adc();

// (4)Define I/O port
     PORTA  = 0b00000000;
     TRISA  = 0b11101011;

// *****************************
//   2.Program main
// *****************************           
    while(1){
        adc_data = Get_adc();
        adc_data_H = ( adc_data / 85 ) + 9;
        adc_data_L = 200 - adc_data_H;
        
        PORTAbits.RA2 = 1;
        Wait_01nmS(adc_data_H);  
        
        PORTAbits.RA2 = 0;
        Wait_01nmS(adc_data_L);  
    };

}

//******************************************************************************************
//   Function Name : Wait_001nmS
//   Title         : This function will wait n times of 1 mS
//   Input         : 
//   Output        :
//******************************************************************************************
void Wait_01nmS(unsigned int n)
{
    unsigned int lp;

    for(lp=0;lp<( n );lp++){
         Wait_01mS();
    } 
}

//******************************************************************************************
//   Function Name : Wait_01mS
//   Title         : This function will wait 0.1mS
//   Input         : 
//   Output        :
//******************************************************************************************
void Wait_01mS(void)
{
    unsigned int lp;
    
    for(lp=0;lp<23;lp++){    
        asm("nop");   
    }
    
}

//******************************************************************************************
//   Program       : Init_adc
//   Title         : 
//   Input         :
//   Output        :
//******************************************************************************************
void Init_adc(void)
{
// *******************************************************
// 1.Define ADCON0(A/D CONTROL REGISTER 0) Register  
//     ADCON0(7)  Unimplemented: Read as '0'
//     ADCON0(6-2) CHS<4:0>: Analog Channel Select bits
//         00000 = AN0
//         00001 = AN1
//         00010 = AN2
//         00011 = AN3
//         00100 = AN4(1)    PIC16F/LF1823 only. For PIC12F/LF1822 it is 'Reserved. No channel connected'
//         00101 = AN5(1)    PIC16F/LF1823 only. For PIC12F/LF1822 it is 'Reserved. No channel connected'
//         00110 = AN6(1)    PIC16F/LF1823 only. For PIC12F/LF1822 it is 'Reserved. No channel connected'
//         00111 = AN7(1)    PIC16F/LF1823 only. For PIC12F/LF1822 it is 'Reserved. No channel connected'
//         10001 = Reserved
//            .
//            .
//            .
//         11101 = Reserved
//         11110 = DAC
//         11111 = FVR
//     ADCON0(1) GO/DONE: A/D Conversion Status bit
//         1 = A/D conversion cycle in progress. Setting this bit starts an A/D conversion cycle.
//             This bit is automatically cleared by hardware when the A/D conversion has completed.
//         0 = A/D conversion completed/not in progress
//     ADCON0(0) ADON: ADC Enable bit
//         1 = ADC is enabled
//         0 = ADC is disabled and consumes no operating current
// ******************************************************* 

    ADCON0 = 0b00000001 ;

    // *******************************************************
// 2.Define ADCON1(A/D CONTROL REGISTER 1) Register  
//     ADCON1(7) ADFM: A/D Result Format Select bit
//         1 = Right justified. Six Most Significant bits of ADRESH are set to '0' when the conversion result is loaded.
//         0 = Left justified. Six Least Significant bits of ADRESL are set to '0' when the conversion result is loaded.
//     ADCON1(6-4)  ADCS<2:0>: A/D Conversion Clock Select bits
//         000 = FOSC/2
//         001 = FOSC/8
//         010 = FOSC/32
//         011 = FRC (clock supplied from a dedicated RC oscillator)
//         100 = FOSC/4
//         101 = FOSC/16
//         110 = FOSC/64
//         111 = FRC (clock supplied from a dedicated RC oscillator)
//     ADCON1(3-2) Unimplemented: Read as '0'
//     ADCON1(1-0) ADPREF<1:0>: A/D Positive Voltage Reference Configuration bits
//         00 = VREF+ is connected to AVDD
//         01 = Reserved
//         10 = VREF+ is connected to external VREF+
//         11 = VREF+ is connected to internal fixed voltage reference
// *******************************************************

    ADCON1 = 0b10010000;

}
//******************************************************************************************
//   Function Name : Get_adc
//   Title         : 
//   Input         : 
//   Output        : ADDAT_H,ADDAT_L
//;******************************************************************************************
unsigned int Get_adc(void)
{
    unsigned int adc_data= 0;
    
// *****************
//  1.Start A/D Converter
// *****************
//  (1)GO/DONE: A/D Conversion Status bit
//  BSF     ADCON0,GO_NOT_DONE
    ADCON0 |= 0b00000010;
    
// *****************
//  2.Get data 
// *****************
//  (1)Wait for the adc start flag
//  BTFSC   ADCON0,GO_NOT_DONE
//  GOTO    $-1
    while((ADCON0 & 0b00000010) != 0);
    
//  (2)Substitute the result
//  MOVF    ADRESH,W  
//  MOVWF   ADDAT_H 
//  MOVF    ADRESL,W  
//  MOVWF   ADDAT_L 
    adc_data = ( ADRESH << 8 ) + ADRESL ;

    return(adc_data);
}