/*
****************************說明**********************
1.stm32f103rct6
2.hc-sr04?:PA0、PA1
3.串口：USART1
4.具體連線及講解見博客：https://blog.csdn.net/sf9090/article/details/105151911
*******************************************************************************
*******************謝謝支持****************************************************
********************************作者：https://blog.csdn.net/sf9090************
*/

#include?
#include?
int?b?=?0;
int?c?=?0;
double?a?=?0;
/*串口輸出*/
int?fputc（int?ch?FILE*fp）
{

	if（fp?==?stdout）
	{
		if（ch?==?‘\n‘）
		{
			while（（USART1->SR?&?USART_SR_TXE）?==?0）;
			USART1->DR?=?‘\r‘;
		}
		while（（USART1->SR?&?USART_SR_TXE）?==?0）;
			USART1->DR?=?ch;
		
	}
	return?0;
	
}
/*
************延時函數***********
*/
void?delay_us（int?x）
{
	TIM1->ARR?=?x-1;
	TIM1->PSC?=?71;
	TIM1->EGR?=?TIM_EGR_UG;
	TIM1->CR1?=?TIM_CR1_OPM?|?TIM_CR1_CEN;?
	while（TIM1->CR1?&?TIM_CR1_CEN）;
}
/*初始化測距模塊*/
void?hcsr04_init（）
{	
	GPIOA->ODR?|=?GPIO_ODR_ODR1;
	?delay_us（20）;
	GPIOA->ODR?&=~?GPIO_ODR_ODR1;
}

int?main（void）
{
	RCC->APB2ENR?=?RCC_APB2ENR_IOPAEN?|?RCC_APB2ENR_USART1EN?|?RCC_APB2ENR_TIM1EN?|?RCC_APB2ENR_AFIOEN;
	RCC->APB1ENR?=?RCC_APB1ENR_TIM2EN;
	GPIOA->CRH?=?（GPIOA->CRH?&?0xffff000f）?|?0x34b0;
	GPIOA->CRL?=?（GPIOA->CRL?&?0xffffff00）?|?0x34;
	USART1->BRR?=?SystemCoreClock?/?9600;
	USART1->CR1?=?USART_CR1_RE?|?USART_CR1_UE?|?USART_CR1_TE;
	printf（“******************stm32f103rct6?HC-SR04**************\n“）;
	AFIO->EXTICR[2]?|=?AFIO_EXTICR1_EXTI0_PA;?
	EXTI->IMR?|=?EXTI_IMR_MR0;?
	EXTI->RTSR?|=?EXTI_RTSR_TR0;
??EXTI->FTSR?|=?EXTI_FTSR_TR0;
	TIM2->ARR?=?65535;
	TIM2->PSC?=?71;
	TIM2->EGR?=?TIM_EGR_UG;
	TIM2->CR1?=??TIM_CR1_CEN;
	NVIC_SetPriority（EXTI0_IRQn?1）;
	NVIC_EnableIRQ（EXTI0_IRQn）;
	
	
	while（1）
	{
		hcsr04_init（）;
	}
}
/*
***********************外部中斷****************
*/
void?EXTI0_IRQHandler（void）
{

	if（GPIOA->IDR&?GPIO_IDR_IDR0）
	{
		TIM2->CR1?|=??TIM_CR1_CEN;
	}
	else	
	{	
		TIM2->CR1?&=~??TIM_CR1_CEN;?
		TIM2->EGR?=?TIM_EGR_UG;

		b=??TIM2->CNT;
		b=b*170/10000;
		printf（“%dcm???“b）;
		for（int?i?=?0;?i?	}
		EXTI->PR?=?EXTI_PR_PR0;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????6956??2015-12-10?17:06??stm32f103rc_hcsr04\DebugConfig\Target_1_STM32F103RC_1.0.0.dbgconf

?????文件????????339??2020-03-27?13:25??stm32f103rc_hcsr04\EventRecorderStub.scvd

?????文件??????53648??2020-03-03?22:35??stm32f103rc_hcsr04\Listings\startup_stm32f10x_hd.lst

?????文件??????54585??2020-03-30?06:51??stm32f103rc_hcsr04\Listings\test.map

?????文件???????2254??2020-03-30?06:51??stm32f103rc_hcsr04\mian.c

?????文件?????????19??2020-03-27?13:26??stm32f103rc_hcsr04\objects\ExtDll.iex

?????文件?????245178??2020-03-30?06:51??stm32f103rc_hcsr04\objects\mian.crf

?????文件????????748??2020-03-30?06:51??stm32f103rc_hcsr04\objects\mian.d

?????文件?????264036??2020-03-30?06:51??stm32f103rc_hcsr04\objects\mian.o

?????文件?????????81??2020-03-03?22:35??stm32f103rc_hcsr04\objects\startup_stm32f10x_hd.d

?????文件???????6704??2020-03-03?22:35??stm32f103rc_hcsr04\objects\startup_stm32f10x_hd.o

?????文件?????241355??2020-03-03?22:35??stm32f103rc_hcsr04\objects\system_stm32f10x.crf

?????文件????????828??2020-03-03?22:35??stm32f103rc_hcsr04\objects\system_stm32f10x.d

?????文件?????260600??2020-03-03?22:35??stm32f103rc_hcsr04\objects\system_stm32f10x.o

?????文件?????253920??2020-03-30?06:51??stm32f103rc_hcsr04\objects\test.axf

?????文件???????2378??2020-03-30?06:51??stm32f103rc_hcsr04\objects\test.build_log.htm

?????文件??????33609??2020-03-30?06:51??stm32f103rc_hcsr04\objects\test.htm

?????文件????????371??2020-03-30?06:51??stm32f103rc_hcsr04\objects\test.lnp

?????文件????????494??2020-03-03?21:20??stm32f103rc_hcsr04\objects\test.sct

?????文件???????2843??2020-03-30?06:51??stm32f103rc_hcsr04\objects\test_Target?1.dep

?????文件??????64999??2016-09-09?13:58??stm32f103rc_hcsr04\RTE\Device\STM32F103RC\RTE_Device.h

?????文件??????15503??2016-11-11?11:18??stm32f103rc_hcsr04\RTE\Device\STM32F103RC\startup_stm32f10x_hd.s

?????文件??????36557??2016-11-11?11:18??stm32f103rc_hcsr04\RTE\Device\STM32F103RC\system_stm32f10x.c

?????文件????????344??2020-03-03?21:06??stm32f103rc_hcsr04\RTE\_Target_1\RTE_Components.h

????.......????178281??2020-03-30?06:51??stm32f103rc_hcsr04\test.uvguix.pc

????.......??????7032??2020-03-27?21:55??stm32f103rc_hcsr04\test.uvoptx

????.......?????16453??2020-03-03?21:23??stm32f103rc_hcsr04\test.uvprojx

?????目錄??????????0??2020-03-03?21:06??stm32f103rc_hcsr04\RTE\Device\STM32F103RC

?????目錄??????????0??2020-03-03?21:06??stm32f103rc_hcsr04\RTE\Device

?????目錄??????????0??2020-03-03?21:06??stm32f103rc_hcsr04\RTE\_Target_1

............此處省略8個文件信息