用STM32用按键/LED/UART实现抢答器实验代码

好的，以下是使用STM32实现抢答器的实验代码，仅供参考：

#include "stm32f10x.h"
#include <stdio.h>

GPIO_InitTypeDef GPIO_InitStructure;
EXTI_InitTypeDef EXTI_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
USART_InitTypeDef USART_InitStructure;

// 定义按键和LED的引脚号
#define KEY1_PIN GPIO_Pin_0
#define KEY2_PIN GPIO_Pin_1
#define KEY3_PIN GPIO_Pin_2
#define KEY4_PIN GPIO_Pin_3
#define LED1_PIN GPIO_Pin_4
#define LED2_PIN GPIO_Pin_5
#define LED3_PIN GPIO_Pin_6
#define LED4_PIN GPIO_Pin_7

// 定义串口接口
#define USARTx USART1
#define USARTx_IRQn USART1_IRQn

// 定义命令
#define CMD_REQ 'R' // 抢答命令
#define CMD_STOP 'S' // 关闭抢答命令
#define CMD_ACK 'A' // 抢答成功命令

// 定义全局变量
uint8_t g_flag = 0; // 抢答标志
uint8_t g_index = 0; // 抢答者编号

// 初始化GPIO口
void GPIO_Configuration(void)
{
  // 使能GPIOA和GPIOB时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);

  // 配置KEY1~KEY4为输入引脚
  GPIO_InitStructure.GPIO_Pin = KEY1_PIN | KEY2_PIN | KEY3_PIN | KEY4_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  // 配置LED1~LED4为输出引脚
  GPIO_InitStructure.GPIO_Pin = LED1_PIN | LED2_PIN | LED3_PIN | LED4_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
}

// 初始化外部中断
void EXTI_Configuration(void)
{
  // 使能AFIO时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);

  // 配置KEY1~KEY4为外部中断
  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource0);
  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource1);
  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource2);
  GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource3);
  EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line1 | EXTI_Line2 | EXTI_Line3;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_Init(&EXTI_InitStructure);

  // 配置优先级
  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);
  NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
  NVIC_Init(&NVIC_InitStructure);
  NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
  NVIC_Init(&NVIC_InitStructure);
  NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
  NVIC_Init(&NVIC_InitStructure);
}

// 初始化串口
void USART_Configuration(void)
{
  // 使能USART1时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

  // 配置USART1引脚
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; // TX
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; // RX
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  // 配置USART1参数
  USART_InitStructure.USART_BaudRate = 9600;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_Parity = USART_Parity_No;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  USART_Init(USARTx, &USART_InitStructure);

  // 使能USART1接收中断
  USART_ITConfig(USARTx, USART_IT_RXNE, ENABLE);

  // 配置优先级
  NVIC_InitStructure.NVIC_IRQChannel = USARTx_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  // 使能USART1
  USART_Cmd(USARTx, ENABLE);
}

// 外部中断服务函数
void EXTI0_IRQHandler(void)
{
  if (EXTI_GetITStatus(EXTI_Line0) != RESET)
  {
    // 触发抢答
    if (!g_flag)
    {
      g_flag = 1;
      g_index = 1;
      GPIO_SetBits(GPIOA, LED1_PIN);
      USART_SendData(USARTx, CMD_REQ);
    }
    EXTI_ClearITPendingBit(EXTI_Line0);
  }
}

void EXTI1_IRQHandler(void)
{
  if (EXTI_GetITStatus(EXTI_Line1) != RESET)
  {
    // 触发抢答
    if (!g_flag)
    {
      g_flag = 1;
      g_index = 2;
      GPIO_SetBits(GPIOA, LED2_PIN);
      USART_SendData(USARTx, CMD_REQ);
    }
    EXTI_ClearITPendingBit(EXTI_Line1);
  }
}

void EXTI2_IRQHandler(void)
{
  if (EXTI_GetITStatus(EXTI_Line2) != RESET)
  {
    // 触发抢答
    if (!g_flag)
    {
      g_flag = 1;
      g_index = 3;
      GPIO_SetBits(GPIOA, LED3_PIN);
      USART_SendData(USARTx, CMD_REQ);
    }
    EXTI_ClearITPendingBit(EXTI_Line2);
  }
}

void EXTI3_IRQHandler(void)
{
  if (EXTI_GetITStatus(EXTI_Line3) != RESET)
  {
    // 触发抢答
    if (!g_flag)
    {
      g_flag = 1;
      g_index = 4;
      GPIO_SetBits(GPIOA, LED4_PIN);
      USART_SendData(USARTx, CMD_REQ);
    }
    EXTI_ClearITPendingBit(EXTI_Line3);
  }
}

// 串口接收中断服务函数
void USARTx_IRQHandler(void)
{
  if (USART_GetITStatus(USARTx, USART_IT_RXNE) != RESET)
  {
    uint8_t data = USART_ReceiveData(USARTx);
    if (data == CMD_ACK)
    {
      // 抢答成功
      g_flag = 0;
      switch (g_index)
      {
        case 1:
          GPIO_ResetBits(GPIOA, LED1_PIN);
          break;
        case 2:
          GPIO_ResetBits(GPIOA, LED2_PIN);
          break;
        case 3:
          GPIO_ResetBits(GPIOA, LED3_PIN);
          break;
        case 4:
          GPIO_ResetBits(GPIOA, LED4_PIN);
          break;
      }
    }
    USART_ClearITPendingBit(USARTx, USART_IT_RXNE);
  }
}

int main(void)
{
  // 初始化GPIO口
  GPIO_Configuration();

  // 初始化外部中断
  EXTI_Configuration();

  // 初始化串口
  USART_Configuration();

  while (1)
  {
  }
}

以上代码仅供参考，具体实现可能需要根据实际情况进行调整和优化。