ADC12单通道多次转换程序详解

采用的是lcd1602液晶显示

#define   Num_of_Results   32
uint results[Num_of_Results];
uchar d[11]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x00};
uchar d1[11]={0xbf,0x86,0xdb,0xcf,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x00};
uchar a[8]={0x7f,0xbf,0xdf,0xef,0xf7,0xfb,0xfd,0xfe};
void main()
{
  // Stop watchdog timer to prevent time out reset
        uchar j; 
        WDTCTL = WDTPW + WDTHOLD;
        //使用外部高频晶体振荡器
        BCSCTL1&=~XT2OFF;
        do{
          IFG1&=~OFIFG;
          for(j=0XFF;j>0;j--);
        }while((IFG1&OFIFG));
        BCSCTL2|=SELM_2;
       
 
        P6DIR&=~(BIT0+BIT1);
        P6SEL |= BIT0+BIT1;  // 使能ADC通道
        ADC12CTL0 = ADC12ON+SHT0_8+MSC;
        // ADC12ON打开ADC，
        //SHT0_8设置采样时间,合适即可
        //MSC设置多次采样
        ADC12CTL1 = CSTARTADD_0+CSTARTADD_1+SHP+CONSEQ_3;
        // CSTARTADD_3让采样结果保存在ADC12MEM3中
        //CONSEQ_2单通道多次转换
        //SHP使用采样定时器
        ADC12IE = BIT0+BIT1;// 中断允许，IFG置位后会进入中断服务程序
        ADC12MCTL0=INCH_0;//通道A1 默认SERF为0，即参考0-AVCC 
        ADC12MCTL1=INCH_1;//通道A1 默认SERF为0，即参考0-AVCC     
        ADC12CTL0 |= ENC+ADC12SC;  // 使能转换并且开始转换       
        ADC12IFG=0;
        _EINT();//打开中断
 while(1);
}
//ADC中断服务函数，在这里用多次平均的        
#pragma vector=ADC_VECTOR
__interrupt void ADC12ISR (void)
{
  static uint index = 0;
      uint i,j;
      uchar ptr[4];
 P4DIR=0XFF;//p4作为输出
        P5DIR=0XFF;
        P6DIR=0XFF;
       
  results[index++] = ADC12MEM0+ADC12MEM1;  // 必须和CSTARTADD_3一样
  if(index == Num_of_Results)
  {
        unsigned long sum = 0,real;

        index = 0;
        for(i = 0; i < Num_of_Results; i++)
        {
            sum += results;
        }
        sum >>= 5;                            //除以32求得平均值
        real=3300*sum/4095;//扩大1000倍    
    ptr[3] = real / 1000;       
    ptr[2] = (real - ptr[3]*1000)/100;
    ptr[1] = (real - ptr[3]*1000 - ptr[2]*100)/10;
    ptr[0] = (real - ptr[3]*1000 - ptr[2]*100 - ptr[1]*10);  
        for(i=0;i<4;i++)
        {
                P4OUT=d[10];
                P5OUT|=BIT5;//设置p5.5为高电平
                P4OUT=a;
                P5OUT^=BIT5;//设置p5.5为低电平    
               
                P6OUT|=BIT6;
                if(i==3)
                P4OUT=d1[ptr];
                else
                P4OUT=d[ptr];
                for(j=0;j<1000;j++);
                P4OUT=d[10];                            
                P6OUT^=BIT6;            
        }  
  }
  ADC12IFG=0;
}