stm32f030c8t6 按键中断例程

### STM32F030C8T6 按键中断示例代码

对于STM32F030C8T6微控制器而言，配置按键中断涉及初始化GPIO端口、设置EXTI线以及编写相应的中断服务程序。下面提供一段基于HAL库的示例代码用于实现按键触发外部中断并控制LED灯的功能。

#### 初始化部分

#include "stm32f0xx_hal.h"

// 定义使用的IO引脚
#define BUTTON_PIN GPIO_PIN_13
#define LED_PIN    GPIO_PIN_5
#define BUTTON_PORT GPIOA
#define LED_PORT   GPIOA

void SystemClock_Config(void);
static void MX_GPIO_Init(void);

int main(void){
  HAL_Init();
  SystemClock_Config();
  
  // 初始化GPIO
  MX_GPIO_Init();

  while (1){
      __WFI(); // 进入低功耗模式等待中断唤醒
  }
}

/**
 * @brief 配置系统时钟
 */
void SystemClock_Config(void){
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /* Configure the main internal regulator output voltage */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /* Initializes the CPU, AHB and APB busses clocks */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK){
    Error_Handler();
  }

  /* Initializes the CPU, AHB and APB busses clocks */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK |RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK){
    Error_Handler();
  }
}

/**
 * @brief GPIO Initialization Function
 */
static void MX_GPIO_Init(void){
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE()

  /*Configure GPIO pin : PA5 as output to control an LED*/
  GPIO_InitStruct.Pin = LED_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(LED_PORT, &GPIO_InitStruct);

  /*Configure GPIO pin : PA13 as input with external interrupt capability for button press detection.*/
  GPIO_InitStruct.Pin = BUTTON_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING; // 下降沿触发
  GPIO_InitStruct.Pull = GPIO_PULLUP;          // 上拉电阻
  HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
}

#### 中断服务程序

/* External Interrupt Service Routine */
void EXTI15_10_IRQHandler(void){
  HAL_GPIO_EXTI_IRQHandler(BUTTON_PIN); // 调用HAL库中的通用处理函数[^2]
}

/* Callback function called by HAL library when a specific line triggers an interrupt event */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
  if(GPIO_Pin == BUTTON_PIN){           // 如果是目标按钮产生的中断
     static uint8_t led_state = 0;
     
     led_state ^= 1;                    // 切换状态
     
     if(led_state){
         HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_SET); // 打开LED
     }else{
         HAL_GPIO_WritePin(LED_PORT, LED_PIN, GPIO_PIN_RESET); // 关闭LED
     }
  }
}

这段代码展示了如何利用STM32F0系列MCU上的硬件资源来创建简单的按键检测机制，并通过改变连接到PA5管脚上LED的状态作为反馈。当按下连接至PA13的开关时，会触发一次下降沿中断请求，在`EXTI15_10_IRQHandler()`中调用了`HAL_GPIO_EXTI_IRQHandler()`完成实际的工作，包括清除中断标志位等操作[^4]。