Atmega8a的采样（查询法）

实现了ADC0和ADC1的切换采样，每个通道采样10次，累计满10次取一次平均，然后输出数据

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在main.c中：

int main（）{

//此处都是初始化的函数

//...........................

while (1) 

    {

ad_calc();

_delay_ms(50);

PORTD |=(1<<5);

_delay_ms(50);

PORTD &=~(1<<5);

    }

}

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void ad_calc()

{

switch(step)

{

case 1:

get;

step=2;

break;

case 2:

switch (ADC_sel(ch))//ch选择

{

case 0://ch=0

get;

result = ADCL;

result = result+(ADCH<<8);

if (adcnt

{

volta[adcnt++] = result;

if (adcnt==ADNUM)//采满

{

ADC_Average_Vol();

ch = ADC_sel(1);

adcnt=0;//采满的计数清零

}

}

break;//ch=0

case 1://ch=1

get;

result = ADCL;

result = result+(ADCH<<8);

if (adcnt

{

volta[adcnt++] = result;

if (adcnt==ADNUM)//采满

{

ADC_Average_Tmp();

ch = ADC_sel(0);

adcnt=0;//采满的计数清零

}

}

break; //ch=1

}

break; //step=2

}

}

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uchar step=1,adcnt=0,ch=0;//AD相关

uint result=0;//存AD值

uint volta[20];//存电压

uint temper[10];//存温度

#define get while(!(ADCSRA & (1 << ADIF)))//若转化完成，ADIF=1

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atmega8和16不同，16的采样可以由定时器触发