stm32按键控制灯的亮灭

可以通过以下步骤实现STM32按键控制LED灯的亮灭：

1. 初始化系统时钟和GPIO口
2. 将LED连接到STM32的一个GPIO引脚上
3. 将按键连接到另一个GPIO引脚上
4. 设置按键引脚为输入模式，LED引脚为输出模式
5. 开启按键的中断功能
6. 在中断服务函数中判断按键是否按下，如果按下则将LED切换状态

以下是一段基于STM32的开发板实现按键控制LED灯的样例代码：

#include "stm32f4xx.h"

//定义LED和按键所连接的GPIO引脚
#define LED_PIN    GPIO_Pin_5
#define LED_PORT   GPIOA
#define KEY_PIN    GPIO_Pin_0
#define KEY_PORT   GPIOB

//初始化系统时钟和GPIO口
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  //使能GPIOA和GPIOB的时钟
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOB, ENABLE);

  // LED的GPIO初始化
  GPIO_InitStructure.GPIO_Pin = LED_PIN;
  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(LED_PORT, &GPIO_InitStructure);

  // KEY的GPIO初始化
  GPIO_InitStructure.GPIO_Pin = KEY_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

  // 开启KEY的中断功能
  EXTI_InitTypeDef EXTI_InitStructure;
  NVIC_InitTypeDef NVIC_InitStructure;
  GPIO_Init(KEY_PORT, &GPIO_InitStructure);
  SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOB, EXTI_PinSource0);
  EXTI_InitStructure.EXTI_Line = EXTI_Line0;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_Init(&EXTI_InitStructure);
  NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

//按键中断服务函数
void EXTI0_IRQHandler(void)
{
  if (EXTI_GetITStatus(EXTI_Line0) != RESET)
  {
    //按键按下
    if (GPIO_ReadInputDataBit(KEY_PORT, KEY_PIN) == 0)
    {
      //切换LED的状态
      if (GPIO_ReadOutputDataBit(LED_PORT, LED_PIN) == 0)
        GPIO_SetBits(LED_PORT, LED_PIN);
      else
        GPIO_ResetBits(LED_PORT, LED_PIN);
    }
    EXTI_ClearITPendingBit(EXTI_Line0);
  }
}

int main(void)
{
  GPIO_Configuration();

  while (1)
  {
    //主循环中不需要进行任何操作
  }
}