void setupADC() {
    AD1PCFG = 0xFFFE; // bit 1 is zero, so AN1 is input
    AD1CHS = 1; // connect bit 0 as input
    AD1CON3bits.ADCS = 0b10; // ADC clock period is Tad = 2 * (ADCS+1) * Tpb
    AD1CON1bits.ADON = 1; // turn on A/D converter
    AD1CON1bits.SSRC = 0b111;
}

int readADC() {
    int i;
    int avg = 0;
    for (i = 0; i < 5; i++) {
        AD1CON1bits.SAMP = 1;
        while (!AD1CON1bits.DONE);
        avg += ADC1BUF0;
    }
    return avg / 5;
}

void makeSinWave() {	// to use this function, the waveform array should be a global variable, and should have a length of 1000
    int i;
    float freq = 2; //frequency in Hz of the sin wave created
    for (i = 0; i < 1000; i++) {
        waveform[i] = 1023 * (.25 * sinf(2.0 * M_PI * i * freq / 1000) + 0.5);
    }
}