Pic12f675 code (XC8 compiler) for boost converter

Pic12f675 code (XC8 compiler) for boost converter

/*
 * File:   main.c
 * Author: root
 *
 * Created on February 8, 2023, 4:56 PM
 */


#pragma config FOSC = HS   // Oscillator Selection bits (INTOSC oscillator: I/O function on GP4/OSC2/CLKOUT pin, I/O function on GP5/OSC1/CLKIN)
#pragma config WDTE = OFF       // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF       // Power-Up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = OFF    // GP3/MCLR pin function select (GP3/MCLR pin function is digital I/O, MCLR internally tied to VDD)
#pragma config BOREN = OFF      // Brown-out Detect Enable bit (BOD disabled)
#pragma config CP = OFF         // Code Protection bit (Program Memory code protection is disabled)
#pragma config CPD = OFF        // Data Code Protection bit (Data memory code protection is disabled)

#include <xc.h>
#define _XTAL_FREQ 20000000

unsigned char PWM = 60;

void __interrupt() isr(void)
{
     if (INTCONbits.T0IF == 1)	{
       if (GP0 == 1) {
     	  TMR0 = PWM + 128;  // 0-127 -> TMR0  128 - 255
     	  GP0 = 0;       //  100 - duty cycle
     } 
     else {
     	  TMR0 = 255 - PWM;  // 0-127  -> TMR0  255 - 128    
     	  GP0 = 1;
     }
    INTCONbits.T0IF = 0;  // Clear Timer1 overflow      
	}    
}

void main(void) {
    TRISIO = 0b00001110; // all output except GP2, GP3, and GP4  (ADC)
    ANSEL =  0b01001110;  // 7=0, 6-4 =conversion clock 101 (4uS), 3-0 analog pins 4,2,1,0
    ADCON0 = 0b00001001;  // // 7=0 right justified, 6=vdd, 5-4 empty, 3-2 ANS2, GO/DONE = 0, ADON=1
    GPIO  =  0x00;
    CMCON =  0x07;  //comparators CM2:CM0 off
    VRCON = 0x00;   // Shut off the Voltage Reference
    OPTION_REG  =   0b11001000; // pre scaler assigned to WDT timer module 
    
        //  nGPPU = 1;      // internal pull ups disabled
        //  INTEDG = 0;     // falling edge trigger the interrupt__don't care
        //  T0CS = 0;       // timer transition on cycle clock
        //  T0SE = 0        // increment on low to high transistion of GP2
        //  PSA = 0         // prescaler is set to the WDT or TIMER0 module
        //  ps2:ps0 >  000 = 1:2  101=1:64
    INTCON  = 0b10100000;  // or 0b10100000;
        //GIE = 1   //enable global interrupts
        //PEIE = 1  //enable peripheral interrupts
        //T0IE = 1  //enable TMR0 interrupts
        //INTE = 0  //disables GP2 interrupt
        //GPIE = 0  //disables GPIO port change interrupt
        //T0IF = 0  //timer0 overflow flag
        //INTF = 0  //GP2 interrupt flag
        //GPIF = 0  //ext pin change interrupt
    T1CON   =   0x00; //clear the unused timer
    PIE1    =   0x00;   //nothing here is needed
    //  http://eng-serve.com/pic/pic_timer.html
    
  
    
    while(1) {
        
        __delay_ms(5);
        GO_nDONE = 1;
        while (GO_nDONE) {
            // wait ADC to complete
        }
        PWM = (ADRESH >> 1);   // 0-127  
        if (PWM < 5) PWM = 5;
       // else if (PWM > 73) PWM = 73;
        else if (PWM > 120) PWM = 120;
    }  // while
    return;
}