//ADEN置位即啟動ADC ，否則ADC功能關(guān)閉。在轉(zhuǎn)換過程中關(guān)閉ADC將立即中止正在進行的轉(zhuǎn)換。同時ADEN清零會將ADIE（AD結(jié)束中斷使能）清除。另外工作在連續(xù)模式下如果沒有對ADEN清零則AD采樣一直運行。

#include "main.h"

#define HOT_MUX 4
#define MIX_MUX 5
#define POWER_MUX 7
#define AD_PORT PORTA
#define AD_DIR DDRA

//采集次數(shù)
#define HOT_SAMP_CNT 4
#define MIX_SAMP_CNT 4
#define POWER_SAMP_CNT 4

unsigned char AD_READY = 0;
volatile unsigned int buf[8];

volatile unsigned int AD_hot_result = 0;
volatile unsigned int AD_mix_result = 0;
volatile unsigned int AD_power_result = 0;

void ADC_Init(void)
{
AD_PORT &= ~(1<AD_DIR &= ~(1< ADMUX = (1<ACSR |= 0x80; //禁止模擬比較器
SFIOR = 0x00; //連續(xù)轉(zhuǎn)換模式
ADCSRA = (1<}

#pragma interrupt_handler ADC_ISR:15
void ADC_ISR(void)
{
unsigned int temp = 0;
static unsigned int sum = 0;
static unsigned char cnt = 0;
static unsigned char AD_status = 0;

if (cnt == 0) //切換通道時第一個數(shù)據(jù)必須舍棄
{
cnt = 1;
ADCSR|=(1}

temp = ADCL;
temp |= (unsigned int)ADCH<<8;
sum += temp;

switch(AD_status)
{
case 0:

if (++cnt > HOT_SAMP_CNT)
{
AD_status++;
ADMUX = (1<AD_hot_result = sum / HOT_SAMP_CNT;
cnt = 0;
sum = 0;
}
break;
case 1:

if (++cnt > MIX_SAMP_CNT)
{
AD_status++;
ADMUX = (1<AD_mix_result = sum / MIX_SAMP_CNT;
cnt = 0;
sum = 0;
}
break;
case 2: //電源電壓
if (++cnt > POWER_SAMP_CNT)
{
AD_status = 1;
ADMUX = (1<AD_power_result = sum / POWER_SAMP_CNT;
cnt = 0;
sum = 0;
AD_READY = 1;

ADCSR &= ~(1}
break;
}
ADCSR|=(1<}

unsigned int Res_Matrixing_Temper(unsigned int temp)
{
float Rt = 0;
float T_inv = 0;
float temper = 0;

Rt = (float)50000*temp/(1024-temp);
T_inv = log(Rt/50000)/3950 + 1/298.15;
temper = (1/T_inv -273.15)*10 + 0.5;

return ((unsigned int)temper);
}

void get_AD_result(void)
{
unsigned int t1 = 0;
float T_inv = 0;
float Rt = 0;
float temp = 0;
if (AD_READY == 1)
{
AD_READY = 0;

t1 = Res_Matrixing_Temper(AD_hot_result);

buf[0] = t1/100;
buf[1] = t1/10%10;
buf[2] = t1%10;

t1 = Res_Matrixing_Temper(AD_mix_result);
buf[3] = t1/100;
buf[4] = t1/10%10;
buf[5] = t1%10;

}
}