adc.c

ICCAVR中所有的库函数源码

/*
**  Purpose:    ADC init & read routines without interrupt.
**
**  Version:    1.0.0, 7:th of October 1999
**
**  Author:     Lars Wictorsson
**              LAWICEL / SWEDEN
**              http://www.lawicel.com   [e-mail]
**
**  History:    1999-10-07  Created
*/

#include <io8535.h>

void InitADC( void)
{
    ADMUX = 0;          // Select channel 0
    ADCSR = 0xC0;       // Enable ADC & start 1:st dummy conversion
}

int ReadADC( unsigned char channel)
{
    int i;

    ADMUX = channel;                        // Select channel
    
    ADCSR |= 0x40;                          // Start conversion
    
    while (!(ADCSR & 0x10));                // Check if converstion is ready
    
    ADCSR |= 0x10;                          // Clear Conversion ready flag by setting the bit

    i = ADCL;                               // Read 8 low bits first (important)
    i += (int)ADCH << 8;                    // Read 2 high bits and multiply with 256

    return i;
}