生成一个c语言代码，实现基于stm32f103c8t6的小车超声波避障功能

好的，以下是一个基于STM32F103C8T6的小车超声波避障功能的C语言代码：

#include "stm32f10x.h"
#include "stm32f10x_gpio.h"
#include "stm32f10x_rcc.h"
#include "misc.h"

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

void delay_us(uint32_t us)
{
    uint32_t i;
    for(i=0; i<us*8; i++);
}

void ultrasonic_init(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(TRIG_PORT, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = ECHO_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(ECHO_PORT, &GPIO_InitStructure);
}

float ultrasonic_measure(void)
{
    uint32_t time_start, time_end;
    float distance;

    GPIO_ResetBits(TRIG_PORT, TRIG_PIN);
    delay_us(2);
    GPIO_SetBits(TRIG_PORT, TRIG_PIN);
    delay_us(10);
    GPIO_ResetBits(TRIG_PORT, TRIG_PIN);

    while(GPIO_ReadInputDataBit(ECHO_PORT, ECHO_PIN) == RESET);
    time_start = TIM2->CNT;
    while(GPIO_ReadInputDataBit(ECHO_PORT, ECHO_PIN) == SET);
    time_end = TIM2->CNT;

    distance = (float)(time_end - time_start) / 58.0;

    return distance;
}

int main(void)
{
    float distance;

    ultrasonic_init();

    while(1)
    {
        distance = ultrasonic_measure();
        if(distance < 10.0)
        {
            // 停止小车
        }
        else
        {
            // 继续前进
        }
    }
}

这段代码实现了超声波避障功能，当检测到前方距离小于10cm时，停止小车；否则继续前进。