STM32单片机读取超声波传感器距离程序

以下是基于STM32单片机读取超声波传感器距离的程序：

#include "stm32f10x.h"

#define TRIG_PIN GPIO_Pin_0
#define ECHO_PIN GPIO_Pin_1
#define TRIG_PORT GPIOA
#define ECHO_PORT GPIOA

int main()
{
    // 初始化GPIO口
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    GPIO_InitStructure.GPIO_Pin = TRIG_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(TRIG_PORT, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = ECHO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(ECHO_PORT, &GPIO_InitStructure);

    // 初始化定时器
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
    TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
    TIM_TimeBaseStructure.TIM_Prescaler = 72 - 1;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    // 等待定时器启动
    TIM_Cmd(TIM2, ENABLE);
    while (TIM_GetFlagStatus(TIM2, TIM_FLAG_Update) == RESET);

    while (1)
    {
        // 触发超声波
        GPIO_ResetBits(TRIG_PORT, TRIG_PIN);
        TIM_SetCounter(TIM2, 0);
        while (TIM_GetFlagStatus(TIM2, TIM_FLAG_Update) == RESET);
        GPIO_SetBits(TRIG_PORT, TRIG_PIN);

        // 等待超声波返回
        while (GPIO_ReadInputDataBit(ECHO_PORT, ECHO_PIN) == RESET);
        TIM_SetCounter(TIM2, 0);
        while (GPIO_ReadInputDataBit(ECHO_PORT, ECHO_PIN) == SET);

        // 计算距离
        uint16_t time = TIM_GetCounter(TIM2);
        float distance = time / 58.0f;

        // 输出距离
        printf("distance: %.2f cm\n", distance);

        // 延时一段时间
        for (int i = 0; i < 1000000; i++);
    }
}

该程序使用了STM32的定时器和GPIO口来控制超声波传感器的触发和接收，并通过计算得出距离。其中，TRIG_PIN和ECHO_PIN分别为超声波传感器的触发和接收引脚，TRIG_PORT和ECHO_PORT为对应的GPIO端口。在主循环中，程序会不断地读取超声波传感器距离并输出。