//ADC 初始化
void ADInit(char channel)
{
	ADC12CTL0 |= ADC12MSC;										//自动循环采样转换
	ADC12CTL0 |= ADC12ON;										//启动ADC12模块
	ADC12CTL1 |= ADC12CONSEQ1 ;									//选择单通道循环采样转换
	ADC12CTL1 |= ADC12SHP;										//采样保持模式
	switch (channel)
	{
            case 0:ADC12MCTL0 |= ADC12INCH_0;    break;			//选择通道0，P6.0
	        case 1:ADC12MCTL0 |= ADC12INCH_1; 	break;			//选择通道1，P6.1
	        case 2:ADC12MCTL0 |= ADC12INCH_2; 	break;			//选择通道2，P6.2
	        case 3:ADC12MCTL0 |= ADC12INCH_3; 	break;			//选择通道3，P6.3
	        case 4:ADC12MCTL0 |= ADC12INCH_4; 	break; 			//选择通道4，P6.4
	        case 5:ADC12MCTL0 |= ADC12INCH_5; 	break; 			//选择通道5，P6.5  连接拨码电位器
	        case 6:ADC12MCTL0 |= ADC12INCH_6; 	break;			//选择通道6，P6.6
	        case 12:ADC12MCTL0 |= ADC12INCH_12; break;	 		//选择通道12，P7.0
	        default: ;break;
	}

	ADC12CTL0 |= ADC12ENC;
}

#define N_POINT 13
unsigned int  GetAD()
{
	unsigned int temp = 0;			//设置变量
	ADC12CTL0 |= ADC12SC;			//开始采样转换
	temp= ADC12MEM0;				//把结果赋给变量
	return temp;
}

unsigned int Filter( )
{
     char count,i,j;
     unsigned int value_buf[N_POINT];
     unsigned int temp=0;
     int sum=0;
	  for (count=0;count<N_POINT;count++)
	  {
	    	value_buf[count] = GetAD();
	  }
	  for (j=0;j<N_POINT-1;j++)
	  {
	    	for (i=0;i<N_POINT-j-1;i++)
		   {
			    if ( value_buf[i]>value_buf[i+1] )
			  {
				   temp = value_buf[i];
				   value_buf[i] = value_buf[i+1];
				   value_buf[i+1] = temp;
			   }
		   }
	}
	for(count=1;count<N_POINT-1;count++)
	sum += value_buf[count];
	//如果为2的n次方等分，则可以用>>n的减少计算量  a=a*8;  可以为 a=a<<3;
	//b=b/8; 可以为b=b>>3;
	return (unsigned int)(sum/(N_POINT-2));
}

unsigned int icnt;
void IO_Init(void)
{
    P8DIR |= BIT1;                          // 设置P8.1口为输出模式  控制LED灯
    P8OUT &= ~BIT1;                          // 选中P8.1为输出方式
    P3DIR |= BIT7;                          // 设置P8.1口为输出模式  控制LED灯
    P3OUT &= ~BIT7;                          // 选中P8.1为输出方式

    P3DIR |= BIT6;                          // 设置P3.6口为输出模式  控制蜂鸣器
    P3OUT |= BIT6;                          // 选中P3.6为输出方式

    P2DIR &= ~(BIT3+BIT6);
    P2REN |= BIT3+BIT6;
    P2OUT |= BIT3+BIT6;

    P1DIR &=~( BIT3+BIT2);
    P1REN = BIT3+BIT2;
    P1OUT |= BIT3+BIT2;
}

int apInterface_Key( void )
{
   return 0;
}

/**
 * main.c
 */
int main(void)
{
    WDTCTL = WDTPW | WDTHOLD;   // stop watchdog timer
    IO_Init();

    ADInit(ADC12INCH_2);

    TA0CTL |= MC_1 + TASSEL_2 + TACLR;      //时钟为SMCLK,比较模式，开始时清零计数器
    TA0CCTL0 = CCIE;                        //比较器中断使能
    TA0CCR0  = 50000;                       //比较值设为50000，相当于50ms的时间间隔
    __enable_interrupt();

    unsigned int ivalue = 0;                                             //设置判断变量
    while(1)
    {
        //  ivalue = GetAD();                                            //没有软件滤波
        ivalue = Filter( );                                              //软件滤波
        if(ivalue>=2500)
        {
            P8OUT |= BIT1;
            P3OUT |= BIT7;
            TA0CTL |= MC_1 + TASSEL_2 + TACLR;      //时钟为SMCLK,比较模式，开始时清零计数器
            icnt=0;
        }
    }

}

#pragma vector = TIMER0_A0_VECTOR
__interrupt void Timer_A (void)
{
    icnt++;
    if(icnt==200)
    {//10s关灯
       P8OUT &= ~BIT1;
       P3OUT &= ~BIT7;
       icnt=0;
    }
}