蓝桥杯超准超声波测距

蓝桥杯单片机组超准超声波测距

void Timer1Init(void) //2000微秒@12.000MHz
{
    AUXR &= 0xBF; //定时器时钟12T模式
    TMOD &= 0x0F; //设置定时器模式
    TMOD |= 0x10; //设置定时器模式
    TL1 = 0x30; //设置定时初值
    TH1 = 0xF8; //设置定时初值
    TF1 = 0; //清除TF1标志
    // TR1 = 1; //定时器1开始计时
}

 

void Sand_wav(void)
{
    unsigned char i;

    for(i=0;i<20;i++)
    {
        P10 = ~P10;
        {unsigned char i;_nop_();_nop_();i = 33;while (--i);}
    }
}


unsigned char Read_wav(void)
{
    float range;

    Sand_wav();
     
    // TR0 = 0;
    TR1 = 1;
    while((P11 != 0) && (TF1 == 0));
    TR1 = 0;
    // TR0 = 1;
     
    if(TF1 == 1)
    {
        TF1 = 0;
        TL1 = 0x30; //设置定时初值
        TH1 = 0xF8; //设置定时初值
        return 99;
    }
    else
    {
        range = TH1*256 + TL1 -63535 +260;
     
        range = range * 0.017;
     
        TL1 = 0x30; //设置定时初值
        TH1 = 0xF8; //设置定时初值
     
        return (unsigned char)range;
    }
}