红外报警系统的c语言程序

//获取有几对红外对管被阻碍
char get_hinder_num()
{
    ......
}
//获取倒计时的时间，立即报警返回0
char get_count_down(char hinder_num)
{
    ......
}
//报警函数
void beep（）
{
    ......
}
flag_delay = 1; //等待标志
void main()
{
    char hinder_num = 0;
    char count_down = 0;
    while(1)
    {
        while(hinder_num == 0){ hinder_num = get_hinder_num();} //发生阻碍跳出
        count_down = get_count_down(); //获取倒计时
        if (count_down == 0){beep()} //倒计时为0，立即报警
        else
        {
            flag_delay = 1;
            ......//使用定时器开始倒计时，根据count_down确定倒计时间
                  //时间到把flag_delay置为0
            while(flag_delay) //等待
            {
                   if (hinder_num != get_hinder_num()) //如果阻碍数量发生变化，退出等待
                   {
                       ......//关闭定时器
                       break;
                   }
            }        
        }

     }   
}