adc.h

AVR单片机m48 8m晶振

//ICC-AVR application builder : 2007-4-3 10:53:29
// Target : M8
// Crystal: 8.0000Mhz

#ifndef		__ADC__H
#define		__ADC__H

void Init_Adc(void);
int Read_Adc(unsigned char channel);

void Init_Adc(void)
{
	ACSR  = 0x80;//will zhao modify:07/04/12
 	//ADMUX = 0x47;//0100 0111 AREF=AVCC
    ADMUX = 0xc7;//1100 0111  AREF=2.56v
    ADCSRA= 0xC7;//Enable ADC & start 1:st dummy conversion
}

int Read_Adc(unsigned char channel)//channel=0x0e 时接测试电压1.23
{
    int i;

    ADMUX = (ADMUX&0xf0)|(0x0F&channel);    // Select channel
    
    ADCSRA|= 0x47;                  // Start conversion
    
    while (!(ADCSRA & 0x10));      // Check if converstion is ready
    
    ADCSRA |= 0x17;                // 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;
}

#endif