stm32f103rct6用库函数控制超声波代码

以下是使用库函数控制超声波模块的代码，适用于STM32F103RCT6：

#include "stm32f10x.h"
#include "delay.h"
#include "lcd.h"
#include "usart.h"

#define Trig GPIO_Pin_7
#define Echo GPIO_Pin_6

void GPIO_Configuration(void);
void TIM_Configuration(void);
void NVIC_Configuration(void);

int main(void)
{
    float distance;
    char buffer[16];
    GPIO_Configuration();
    TIM_Configuration();
    NVIC_Configuration();
    USART_Configuration();
    LCD_Configuration();
    while(1)
    {
        GPIO_SetBits(GPIOB, Trig);
        delay_us(10);
        GPIO_ResetBits(GPIOB, Trig);

        while(GPIO_ReadInputDataBit(GPIOB, Echo) == RESET);

        TIM_Cmd(TIM2, ENABLE);
        while(GPIO_ReadInputDataBit(GPIOB, Echo) == SET);
        TIM_Cmd(TIM2, DISABLE);

        distance = (float)TIM_GetCounter(TIM2) / 58.0;
        sprintf(buffer, "Distance:%.2fcm", distance);
        USART_SendString(buffer);
        LCD_Clear();
        LCD_DisplayStringLine(Line1, buffer);
    }
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    GPIO_InitStructure.GPIO_Pin = Trig;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = Echo;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
}

void TIM_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_TimeBaseStructure.TIM_Period = 65535;
    TIM_TimeBaseStructure.TIM_Prescaler = 71;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
}

void NVIC_Configuration(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

    NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
}

void TIM2_IRQHandler(void)
{
    if(TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
    }
}

代码中使用了STM32F10x标准库，并且需要提前配置好LCD和USART。其中Trig和Echo分别对应超声波模块的Trig和Echo引脚，TIM2用于计时，计算出超声波返回的时间，进而计算出距离。在主函数中，不断获取距离并通过USART发送出去，同时在LCD上显示。注意，本代码中距离单位为厘米。