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72MHzSystemInit();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_APB 2Periph_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,ENAB LE);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;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;GPIO_Init(GPIOy, &GPIO_InitStructure);}//打印显示汉字程序，包括设定显示坐标，显示内容void hanzi(unsigned char x,unsigned char y,unsigned char *z) //显示汉字字符{unsigned char pos;if(x==0)x=0x80;if(x==1)x=0x90;if(x==2)x=0x88;if(x==3)x=0x98;pos=x+y;write_com(pos);while(*z!='\0'){write_date(*z);z++;}}//主函数内容int main(void){u8 a,b,c,d;SystemInit();GPIO_Configuration();//串口引脚初始化USART_Configuration(9600);//串口初始化，方便系统调试Delay_Configuration(72);//系统延时函数初始化Sonic_Init();//超声波初始化initlcd12864();//液晶显示模块初始化printf("\n OK \n"); //初始化结束串口打印OK信息while(1){a=Sonic1();b=Sonic2();c=Sonic3();d=Sonic4();if(a<=100) hanzi(0,0,"1号车位无车");else hanzi(0,0,"1号车位有车");if(b<=100) hanzi(0,0,"2号车位无车");else hanzi(0,0,"2号车位有车");if(c<=100) hanzi(0,0,"3号车位无车");else hanzi(0,0,"3号车位有车");if(d<=100) hanzi(0,0,"4号车位无车");else hanzi(0,0,"4号车位有车");delayms(100);}}。
