Pic16f188xx ADC with fvr

 #include <xc.h>

// Configuration bits

#pragma config FOSC = INTOSC // Internal Oscillator

#pragma config WDTE = OFF // Watchdog Timer Disable

#pragma config PWRTE = OFF // Power-up Timer Disable

#pragma config MCLRE = ON // MCLR Pin Function Select

#pragma config CP = OFF // Flash Program Memory Code Protection

#pragma config BOREN = ON // Brown-out Reset Enable

#pragma config CLKOUTEN = OFF // Clock Out Disable

#pragma config IESO = OFF // Internal/External Switchover

#pragma config FCMEN = OFF // Fail-Safe Clock Monitor Disable

// Define system frequency

#define _XTAL_FREQ 32000000 // 32 MHz internal oscillator

void setup(void) {

    // Initialize oscillator

    OSCCON1 = 0x60; // Set OSCCON1 - HFINTOSC with 1x divider

    OSCFRQ = 0x06; // Set OSCFRQ - 32MHz HFINTOSC

    // Initialize FVR to 2.048V for ADC

    FVRCON = 0b11000010; // FVREN enabled, ADC FVR Buffer Gain is 2x (2.048V)

    // Set RA0/AN0 as analog input

    TRISAbits.TRISA0 = 1; // Configure RA0 as input

    ANSELAbits.ANSELA0 = 1; // Enable analog functionality on RA0

    // ADC configuration

    ADCON0 = 0x01; // ADON enabled, channel AN0

    ADCON1 = 0b11010000; // ADFM right justified, ADPREF FVR, ADCS FOSC/64

    ADREF = 0b00110000; // ADNREF VSS, ADPREF FVR (2.048V)

}

uint16_t readADC(void) {

    __delay_us(5); // Acquisition time delay

    ADCON0bits.GO = 1; // Start ADC conversion

    while (ADCON0bits.GO); // Wait for conversion to complete

    return ((uint16_t)((ADRESH << 8) + ADRESL)); // Return right-justified 10-bit result

}

void main(void) {

    setup();

    

    while(1) {

        uint16_t adcResult = readADC(); // Read ADC value from AN0

        // Implement your application logic here

        __delay_ms(1000); // Example delay, modify as per application requirement

    }

}