adc.c

PIc24 Real time clock with alarm and 10sec interruptions

/*
 * ADC.c
 */
#include <p24fj128ga010.h>

// initialize the ADC for single conversion, select Analog input pins
void initADC( int amask) 
{
    AD1PCFG = amask;    // select analog input pins
    AD1CON1 = 0x00E0;   // auto convert after end of sampling 
//    AD1CON1 = 0x0004;   // auto sample after conversion
    AD1CSSL = 0;        // no scanning required 
    AD1CON3 = 0x1F02;   // max sample time = 31Tad, Tad = 3 x Tcy >75ns
    AD1CON2 = 0;        // use MUXA, AVss and AVdd are used as Vref+/-
    AD1CON1bits.ADON = 1; // turn on the ADC
} //initADC


int readADC( int ch)
{
    AD1CHS  = ch;               // select analog input channel
    AD1CON1bits.SAMP = 1;       // start sampling, automatic conversion will follow
    while (!AD1CON1bits.DONE);  // wait to complete the conversion
    return ADC1BUF0;            // read the conversion result
} // readADC