stm32f4定时器3灯亮2s

以下是使用stm32f4定时器3实现灯亮2s的代码：

#include "stm32f4xx.h"

void delay_ms(uint32_t ms)
{
    for (uint32_t i = 0; i < ms; i++)
    {
        for (volatile uint32_t j = 0; j < 2000; j++);
    }
}

int main(void)
{
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_TimeBaseStructure.TIM_Period = 2000 - 1;
    TIM_TimeBaseStructure.TIM_Prescaler = 8400 - 1;
    TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

    TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
    NVIC_InitTypeDef NVIC_InitStructure;
    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);

    while (1)
    {
        GPIO_SetBits(GPIOA, GPIO_Pin_5);
        delay_ms(500);
        GPIO_ResetBits(GPIOA, GPIO_Pin_5);
        delay_ms(500);
    }
}

void TIM3_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
        TIM_Cmd(TIM3, DISABLE);
    }
}