esp8266接收数据后通过stm32f103c8t6的usart3串口传回单片机代码实现

下面是将ESP8266接收到的数据通过STM32F103C8T6的USART3串口传回单片机的代码实现。

首先，要在STM32F103C8T6上配置USART3串口。可以使用STM32CubeMX进行配置，也可以手动编写代码进行配置。下面是手动编写代码进行配置的示例：

#include "stm32f10x.h"

void USART3_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;

  //使能USART3和GPIOB时钟
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  //将USART3的Tx引脚（PB10）配置为复用推挽输出
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  //将USART3的Rx引脚（PB11）配置为浮空输入
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  //USART3的参数配置
  USART_InitStructure.USART_BaudRate = 115200;
  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(USART3, &USART_InitStructure);

  //使能USART3
  USART_Cmd(USART3, ENABLE);
}

接下来，可以使用ESP8266的AT指令将ESP8266设置为透传模式，以便将接收到的数据直接传回STM32F103C8T6。

void ESP8266_Setup(void)
{
  USART3_Config();

  //ESP8266进入透传模式
  USART3_SendString("AT+CIPMODE=1\r\n");
  USART3_WaitForResponse("OK\r\n");
  USART3_SendString("AT+CIPSTART=\"TCP\",\"192.168.1.100\",8000\r\n");
  USART3_WaitForResponse("OK\r\n");
  USART3_SendString("AT+CIPSEND\r\n");
  USART3_WaitForResponse(">");
}

在透传模式下，ESP8266会将接收到的数据直接通过TCP连接发送给指定的IP地址和端口号。在这个示例中，IP地址为192.168.1.100，端口号为8000。可以根据实际情况进行修改。

最后，可以在STM32F103C8T6的USART3接收中断中读取接收到的数据，并将数据发送回ESP8266的TCP连接。

void USART3_IRQHandler(void)
{
  if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET)
  {
    uint8_t data = USART_ReceiveData(USART3);
    USART_SendData(USART3, data);
    while(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);
  }
}

需要注意的是，在发送数据之前，需要先等待ESP8266发送的提示符“>”出现，表示可以开始发送数据。可以使用USART3_WaitForResponse函数来等待ESP8266的响应。

void USART3_WaitForResponse(char* response)
{
  char buffer[100];
  uint8_t i = 0;

  while(1)
  {
    if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET)
    {
      uint8_t data = USART_ReceiveData(USART3);
      buffer[i++] = data;

      if(strstr(buffer, response) != NULL)
      {
        break;
      }
    }
  }
}

完整的代码如下所示：

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

void USART3_Config(void);
void ESP8266_Setup(void);
void USART3_WaitForResponse(char* response);

int main(void)
{
  USART3_Config();
  ESP8266_Setup();

  while(1);

  return 0;
}

void USART3_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;

  //使能USART3和GPIOB时钟
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  //将USART3的Tx引脚（PB10）配置为复用推挽输出
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  //将USART3的Rx引脚（PB11）配置为浮空输入
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  //USART3的参数配置
  USART_InitStructure.USART_BaudRate = 115200;
  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(USART3, &USART_InitStructure);

  //使能USART3
  USART_Cmd(USART3, ENABLE);

  //使能USART3接收中断
  USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);
  NVIC_EnableIRQ(USART3_IRQn);
}

void ESP8266_Setup(void)
{
  USART3_SendString("AT+CIPMODE=1\r\n");
  USART3_WaitForResponse("OK\r\n");
  USART3_SendString("AT+CIPSTART=\"TCP\",\"192.168.1.100\",8000\r\n");
  USART3_WaitForResponse("OK\r\n");
  USART3_SendString("AT+CIPSEND\r\n");
  USART3_WaitForResponse(">");
}

void USART3_WaitForResponse(char* response)
{
  char buffer[100];
  uint8_t i = 0;

  while(1)
  {
    if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET)
    {
      uint8_t data = USART_ReceiveData(USART3);
      buffer[i++] = data;

      if(strstr(buffer, response) != NULL)
      {
        break;
      }
    }
  }
}

void USART3_SendString(char* string)
{
  while(*string)
  {
    USART_SendData(USART3, *string++);
    while(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);
  }
}

void USART3_IRQHandler(void)
{
  if(USART_GetITStatus(USART3, USART_IT_RXNE) != RESET)
  {
    uint8_t data = USART_ReceiveData(USART3);
    USART_SendData(USART3, data);
    while(USART_GetFlagStatus(USART3, USART_FLAG_TXE) == RESET);
  }
}