ESP32-01S怎么和stm32串口通信

ESP32-01S和STM32可以通过串口进行通信，下面是基本的接线和通信代码：

1. 接线

ESP32-01S | STM32
-|-
TX | RX
RX | TX
GND | GND

2. 代码

在STM32的代码中，需要使用UART（串口）进行通信。具体实现可以参考下面的代码示例：

#include <stdio.h>
#include <string.h>
#include "stm32f4xx.h"

#define UART_TX_PIN GPIO_Pin_9
#define UART_RX_PIN GPIO_Pin_10

void USART1_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;

  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_USART1);
  GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_USART1);

  GPIO_InitStructure.GPIO_Pin = UART_TX_PIN | UART_RX_PIN;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);

  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(USART1, &USART_InitStructure);

  USART_Cmd(USART1, ENABLE);
}

void USART1_SendChar(char ch)
{
  while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
  USART_SendData(USART1, (uint16_t) ch);
}

char USART1_ReceiveChar(void)
{
  while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET);
  return (char) USART_ReceiveData(USART1);
}

int main(void)
{
  USART1_Init();

  while (1)
  {
    // 发送数据
    USART1_SendChar('H');
    USART1_SendChar('e');
    USART1_SendChar('l');
    USART1_SendChar('l');
    USART1_SendChar('o');
    USART1_SendChar('\n');

    // 接收数据
    char ch = USART1_ReceiveChar();
    if (ch != '\0')
    {
      printf("Received: %c\n", ch);
    }
  }
}

在ESP32-01S的代码中，同样需要使用UART进行通信。具体实现可以参考下面的代码示例：

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/uart.h"

#define UART_TX_PIN 1
#define UART_RX_PIN 3

void uart_init(void)
{
    uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity    = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
    };
    uart_param_config(UART_NUM_1, &uart_config);
    uart_set_pin(UART_NUM_1, UART_TX_PIN, UART_RX_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
    uart_driver_install(UART_NUM_1, 1024, 1024, 0, NULL, 0);
}

void uart_send(char* data, int len)
{
    uart_write_bytes(UART_NUM_1, data, len);
}

void uart_receive(void *pvParameters)
{
    char data[256];
    while (1)
    {
        int len = uart_read_bytes(UART_NUM_1, (uint8_t*) data, sizeof(data), 100 / portTICK_RATE_MS);
        if (len > 0)
        {
            printf("Received: %s\n", data);
        }
    }
}

void app_main()
{
    uart_init();

    xTaskCreate(uart_receive, "uart_receive", 1024 * 2, NULL, 10, NULL);

    while(1)
    {
        // 发送数据
        uart_send("Hello\n", 6);
        vTaskDelay(1000 / portTICK_RATE_MS);
    }
}

需要注意的是，在ESP32-01S的代码中，我们使用了FreeRTOS来创建一个任务来接收串口数据。