车位诱导程序：
（1）系统初始化：
一般情况，直接调用此函数将单片机系统时钟设置在72MHz
SystemInit();
程序中经常要用到延时函数，在这里为了提高CPU工作效率，不再使用死等待的演示方式，而是采用定时器作延时。
void Delay_Configuration(u8 SYSCLK)
{
    RCC_APB1PeriphClockCmd(Delay_RCC_APB1Periph_TIMx, ENABLE);       
    TIM_PrescalerConfig(Delay_TIMx, SYSCLK, TIM_PSCReloadMode_Update);
}
（2）超声波检测模块初始化
//超声波软件系统初始化
void Sonic_Init(void)
{
    Sonic_RCC_Configuration();
    Sonic_GPIO_Configuration();
    Sonic_NVIC_Configuration();
    Sonic_TIM_Configuration();
}：
//打开超声波需要使用的系统资源的时钟
void Sonic_RCC_Configuration(void)
{
    RCC_APB2PeriphClockCmd(SONIC_RCC_APB2Periph_GPIOx_OUT|SONIC_RCC_APB2Periph_GPIOx_IN,ENABLE);//打开时钟
    RCC_APB1PeriphClockCmd(SONIC_RCC_APB1Periph_TIMx,ENABLE);
}
//这里设置超声波检测所需要的引脚的相应功能
void Sonic_GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
/*············波形输出 驱动超声波···········*/
    GPIO_InitStructure.GPIO_Pin=SONIC_GPIO_Pinx_OUT;
    GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;//
    GPIO_Init(SONIC_GPIOx_OUT,&GPIO_InitStructure);
    GPIO_InitStructure.GPIO_Pin =  SONIC_GPIO_Pinx_IN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(SONIC_GPIOx_IN, &GPIO_InitStructure);
                                           
}
//打开中断，设置中断优先级
void Sonic_NVIC_Configuration(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);          //设置优先级
    NVIC_InitStructure.NVIC_IRQChannel=SONIC_TIMx_IRQn;//使能外部中断线1(IRQ通道)
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;    //先占优先级
    NVIC_InitStructure.NVIC_IRQChannelSubPriority=0;        //从优先级
    NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
    NVIC_Init(&NVIC_InitStructure); 
}
//定时器的初始化配置
void Sonic_TIM_Configuration(void)
{   
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;   
    TIM_ICInitTypeDef TIM_ICInitStructure;
   
    /*通用定时器配置*/
    TIM_TimeBaseStructure.TIM_Period =65535;        //TIMx->ARR    设置自动装载值
    TIM_TimeBaseStructure.TIM_Prescaler =72;        //TIMx->PSC  设置预分频器值
    TIM_TimeBaseStructure.TIM_ClockDivision =TIM_CKD_DIV1;//设置时钟频率
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; /选择计数器模式
    TIM_TimeBaseInit(SONIC_TIMx, & TIM_TimeBaseStructure);
    TIM_OCStructInit(&TIM_OCInitStructure);        //默认参数
    TIM_OCInitStructure.TIM_OCMode=TIM_OCMode_PWM1;//模式1设置输出比较3模式
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //设置为输出
    TIM_OCInitStructure.TIM_Pulse =21;        //设置捕获比较寄存器4值即占空长度
    TIM_OCInitStructure.TIM_OCPolarity=TIM_OCPolarity_High;//设置输出极性-高电平
      TIM_OC4Init(SONIC_TIMx, &TIM_OCInitStructure);        //初始化TIMx通道4.
    TIM_OC4PreloadConfig(SONIC_TIMx, TIM_OCPreload_Enable);              //TIMx->CCMR2 OC4PE 输出比较4的预加载使能位
    TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
    TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
    TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
    TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICFilter = 0x0;
    TIM_PWMIConfig(SONIC_TIMx, &TIM_ICInitStructure);   
    /* Select the TIM3 Input Trigger: TI2FP2 */
    TIM_SelectInputTrigger(SONIC_TIMx, TIM_TS_TI2FP2);   
    /* Select the slave Mode: Reset Mode */
    TIM_SelectSlaveMode(SONIC_TIMx, TIM_SlaveMode_Reset);   
    /* Enable the Master/Slave Mode */
    TIM_SelectMasterSlaveMode(SONIC_TIMx, TIM_MasterSlaveMode_Enable);   
    /* TIM enable counter */
    TIM_Cmd(SONIC_TIMx, ENABLE);   
    /* Enable the CC2 Interrupt Request */
    TIM_ITConfig(SONIC_TIMx, TIM_IT_CC2, ENABLE);
}
//定时器中断里边的内容
void TIMx_IRQHandler(void)
{
    if(TIM_GetITStatus(SONIC_TIMx,TIM_IT_CC2)!=RESET)
    {
        TIM_ClearITPendingBit(SONIC_TIMx,TIM_IT_CC2);
        value1=TIM_GetCapture2(SONIC_TIMx);
        if(value1!=0)
        {
            value2=TIM_GetCapture1(SONIC_TIMx);
        }
        else
        {
            value1=0;
            value2=0;   
        }
        time=value2;   
    }
}
//12864液晶显示模块初始化
//初始化液晶，引脚初始化，发送初始化命令
void initlcd12864()
{
    GPIO_Config();
    write_com(0x30);
    delayms(1);
    write_com(0x0c);//整体显示开 游标关 游标位置关
    delayms(1);
    write_com(0x01);
    delayms(5);   
}
//液晶引脚资源初始化
void GPIO_Config(void)
{   
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOx|RCC_APB2Periph_GPIOy,ENABLE);
单片机printf函数    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(GPIOx, &GPIO_InitStructure);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8|GPIO_Pin_9|GPIO_Pin_10;