AVR单片机ADC转换程序

#defineAD_ref_vref0x00//基准Vref

#defineAD_ref_avcc0x40//基准AVCC

#defineAD_ref_vref_in0xc0//基准内部Vref

#defineAD_refAD_ref_vref

//常量定义

//单端通道,不放大

#define AD_SE_ADC0 0x00//ADC0

#define AD_SE_ADC1 0x01//ADC1

#define AD_SE_ADC2 0x02//ADC2

#define AD_SE_ADC3 0x03//ADC3

#define AD_SE_ADC4 0x04//ADC4

#define AD_SE_ADC5 0x05//ADC5

#define AD_SE_ADC6 0x06//ADC6

#define AD_SE_ADC7 0x07//ADC7

//定义AD端口变量

#define AD_TEMPAD_SE_ADC0//ADC0

#define AD_VOUTAD_SE_ADC1//ADC1

#define AD_KEYINAD_SE_ADC2//ADC2

#defineAD_VINAD_SE_ADC3//ADC3

#define AD_IOUTAD_SE_ADC4//ADC4

#define AD_6BATAD_SE_ADC5//ADC5

#defineBAT_SE_PORTPORTB

#defineBAT_EN_PORTPORTB

#defineBAT_EN_PIN0X03

void adc_init(void)

{

DDRA=0x00;

ADCSRA=(1<

//ADMUX=(1<

//DIDR0=(1<

}

unsigned int read_adc(unsigned char adc_input,unsigned char i)//查询方式读取ADC单端通道

{

unsigned charx;

unsigned inty=0;

ADC=0;

    ADMUX=(AD_ref|adc_input);//adc_input:单端通道 0x00~0x07,0x1E,0x1F

    //0xc0:选择内部2.56V参考电压

delay_nus(100);

for(x=0;x

{

    ADCSRA|=(1<

    loop_until_bit_is_set(ADCSRA,ADIF);//方法1 等待AD转换结束

//  while ((ADCSRA&(1<

//  loop_until_bit_is_clear(ADCSRA,ADSC);//方法2 检测ADSC=0也行

    ADCSRA|=(1<

y += ADC;//ADC=ADCH:ADCL

}

    return y;

}