写一段stm32超声波避障小车代码

好的，以下是一个基于STM32的超声波避障小车代码，供您参考：

#include "stm32f10x.h"
#include "stm32f10x_tim.h"

#define TRIG_PIN GPIO_Pin_0
#define ECHO_PIN GPIO_Pin_1
#define LEFT_MOTOR_1 GPIO_Pin_2
#define LEFT_MOTOR_2 GPIO_Pin_3
#define RIGHT_MOTOR_1 GPIO_Pin_4
#define RIGHT_MOTOR_2 GPIO_Pin_5

uint16_t distance = 0;

void GPIO_Configuration(void);
void TIM_Configuration(void);
void Delay(uint32_t nCount);
void TIM2_IRQHandler(void);

int main(void)
{
    GPIO_Configuration();
    TIM_Configuration();

    while (1)
    {
        GPIO_SetBits(GPIOA, TRIG_PIN);
        Delay(10);
        GPIO_ResetBits(GPIOA, TRIG_PIN);

        while (GPIO_ReadInputDataBit(GPIOA, ECHO_PIN) == 0);
        TIM_Cmd(TIM2, ENABLE);
        while (GPIO_ReadInputDataBit(GPIOA, ECHO_PIN) == 1);
        TIM_Cmd(TIM2, DISABLE);

        distance = TIM_GetCounter(TIM2) / 58;

        if (distance > 10)
        {
            GPIO_SetBits(GPIOA, LEFT_MOTOR_1);
            GPIO_ResetBits(GPIOA, LEFT_MOTOR_2);
            GPIO_SetBits(GPIOA, RIGHT_MOTOR_1);
            GPIO_ResetBits(GPIOA, RIGHT_MOTOR_2);
        }
        else
        {
            GPIO_ResetBits(GPIOA, LEFT_MOTOR_1);
            GPIO_SetBits(GPIOA, LEFT_MOTOR_2);
            GPIO_ResetBits(GPIOA, RIGHT_MOTOR_1);
            GPIO_SetBits(GPIOA, RIGHT_MOTOR_2);
            Delay(500);
        }
    }
}

void GPIO_Configuration(void)
{
    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(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = ECHO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = LEFT_MOTOR_1 | LEFT_MOTOR_2 | RIGHT_MOTOR_1 | RIGHT_MOTOR_2;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void TIM_Configuration(void)
{
    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 = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

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

void TIM2_IRQHandler(void)
{
    TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
}

void Delay(uint32_t nCount)
{
    for(; nCount != 0; nCount--);
}

这是一个基本的超声波避障小车程序，其中使用了一个超声波传感器来感知车辆前方的障碍物。在主循环中，首先发送一个10微秒的脉冲信号，然后等待回波信号，使用定时器计算出距离。如果距离大于10厘米，则向前移动，否则后退一段时间。

需要注意的是，此程序仅供参考，具体实现可能因车辆硬件配置、传感器精度等因素而有所不同。