stm32f407风速检测代码

以下是基于STM32F407的风速检测代码。这个代码使用定时器捕获来检测风速传感器的输出脉冲，并通过计算来计算风速的频率。

#include "stm32f4xx.h"

#define PULSE_PER_ROTATION  1  // 转一圈的脉冲数
#define WIND_SPEED_FACTOR   2.4  // 风速传感器系数

void TIM3_IRQHandler(void)
{
    static uint32_t last_capture = 0;
    static uint32_t current_capture = 0;
    static uint32_t capture_count = 0;

    if (TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET) {
        TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);
        current_capture = TIM_GetCapture1(TIM3);

        if (current_capture > last_capture) {
            capture_count += current_capture - last_capture;
        } else {
            capture_count += (0xFFFF - last_capture) + current_capture;
        }

        last_capture = current_capture;
    }
}

int main(void)
{
    // 初始化GPIO
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // 将GPIO引脚映射到TIM3通道1
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_TIM3);

    // 初始化TIM3
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_ICInitTypeDef TIM_ICInitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
    TIM_TimeBaseStructure.TIM_Prescaler = 0;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

    TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
    TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
    TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
    TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
    TIM_ICInitStructure.TIM_ICFilter = 0x0;
    TIM_ICInit(TIM3, &TIM_ICInitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    TIM_Cmd(TIM3, ENABLE);
    TIM_ITConfig(TIM3, TIM_IT_CC1, ENABLE);

    while (1) {
        uint32_t capture_count_copy = capture_count;
        capture_count = 0;

        float wind_speed = (float)capture_count_copy / (PULSE_PER_ROTATION * WIND_SPEED_FACTOR);
        // 使用风速值进行下一步处理
    }
}

这个代码使用了TIM3通道1来捕获风速传感器的脉冲，并且使用了定时器中断来处理捕获事件。在每个定时器中断中，我们计算出自上次捕获以来的脉冲数，并且将其存储在 `capture_count` 变量中。我们然后可以使用这个计数器来计算风速的频率，并进行下一步处理。