#include <detpic32.h>

#define SAMPLES 16

int main() {
    TRISBbits.TRISB4 = 1;                   // RB4 digital output disconnected
    AD1PCFGbits.PCFG4 = 0;                  // RB4 configured as analog input (AN4)
    AD1CON1bits.SSRC = 7;                   // Conversion trigger selection bits: in this
                                            // mode an internal counter ends sampling and
                                            // starts conversion
    AD1CON1bits.CLRASAM = 1;                // Stop conversions when the 1st A/D converter
                                            // interrupt is generated. At the same time, hardware
                                            // clears the ASAM bit
    AD1CON3bits.SAMC = 16;                  // Sample time is 16 TAD (TAD = 100 ns)
    AD1CON2bits.SMPI = SAMPLES - 1;         // Interrupt is generated after 16 samples
    AD1CHSbits.CH0SA = 4;                   // Selects AN4 as input for the A/D converter
    AD1CON1bits.ON = 1;                     // Enable A/D converter

    while (1) {
        AD1CON1bits.ASAM = 1;               // Start conversion
        while (IFS1bits.AD1IF == 0);        // Wait while conversion not done
        int total = 0;
        int *p = (int *)(&ADC1BUF0);
        for (; p <= (int *)(&ADC1BUFF); p+=4)
            total += *p;
        int val_ad = total / SAMPLES;
        int v = (val_ad * 33 + 511) / 1023;
        printStr("VAL_AD value: ");
        printInt(val_ad, 10 | 4 << 16);     // Print ADC1BUF0 value
        printStr("  |  V value: ");
        printInt(v, 10 | 4 << 16);          // Print ADC1BUF0 value
        putChar('\r');
        IFS1bits.AD1IF = 0;                 // Reset AD1IF
    }

    return 0;
}