stm32对定时器2通道34输出的pwn波记高电平次数代码

以下是使用STM32的定时器2通道3和4输出PWM波，并记录高电平次数的代码示例：

#include "stm32f4xx.h"

int main(void)
{
    // 初始化GPIO
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

    GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_TIM2);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_TIM2);

    // 初始化定时器
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;
    TIM_TimeBaseInitStruct.TIM_Period = 9999; // PWM频率为10kHz
    TIM_TimeBaseInitStruct.TIM_Prescaler = 83; // 定时器时钟为84MHz/84=1MHz
    TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStruct);

    TIM_OCInitTypeDef TIM_OCInitStruct;
    TIM_OCInitStruct.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStruct.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStruct.TIM_Pulse = 4999; // 占空比50%
    TIM_OCInitStruct.TIM_OCPolarity = TIM_OCPolarity_High;

    TIM_OC3Init(TIM2, &TIM_OCInitStruct);
    TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Enable);

    TIM_OC4Init(TIM2, &TIM_OCInitStruct);
    TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Enable);

    TIM_Cmd(TIM2, ENABLE);

    // 记录高电平次数
    uint32_t cnt = 0;
    while (1)
    {
        if (TIM2->CCR3 > 4999 / 2) // 通道3输出高电平
        {
            cnt++;
        }
    }
}

该代码使用的是STM32F4xx系列微控制器，使用定时器2的通道3和4分别输出PWM波，并通过TIM2->CCR3寄存器检测通道3输出的PWM波是否为高电平，从而记录高电平次数。