esp32与stm32串口通信代码

以下是一个简单的 ESP32 和 STM32 串口通信的示例代码：

ESP32 代码：

#include <HardwareSerial.h>

HardwareSerial Serial2(2);

void setup() {
  Serial.begin(115200);
  Serial2.begin(115200, SERIAL_8N1, 16, 17);
}

void loop() {
  if (Serial2.available()) {
    char c = Serial2.read();
    Serial.print(c);
  }
  if (Serial.available()) {
    char c = Serial.read();
    Serial2.print(c);
  }
}

STM32 代码：

#include "stm32f1xx.h"
#include "stm32f1xx_hal.h"

UART_HandleTypeDef huart1;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART1_UART_Init(void);

int main(void) {

  HAL_Init();

  SystemClock_Config();

  MX_GPIO_Init();
  MX_USART1_UART_Init();

  while (1) {
    uint8_t c;
    if (HAL_UART_Receive(&huart1, &c, 1, HAL_MAX_DELAY) == HAL_OK) {
      HAL_UART_Transmit(&huart1, &c, 1, HAL_MAX_DELAY);
    }
  }
}

void SystemClock_Config(void) {
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** 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_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

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

static void MX_USART1_UART_Init(void) {

  huart1.Instance = USART1;
  huart1.Init.BaudRate = 115200;
  huart1.Init.WordLength = UART_WORDLENGTH_8B;
  huart1.Init.StopBits = UART_STOPBITS_1;
  huart1.Init.Parity = UART_PARITY_NONE;
  huart1.Init.Mode = UART_MODE_TX_RX;
  huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart1.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart1) != HAL_OK) {
    Error_Handler();
  }
}

static void MX_GPIO_Init(void) {
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOA_CLK_ENABLE();

  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0, GPIO_PIN_RESET);

  GPIO_InitStruct.Pin = GPIO_PIN_0;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

在这个例子中，ESP32 和 STM32 同时使用 115200 的波特率进行通信。ESP32 使用了 HardwareSerial 库来简化代码，而 STM32 直接使用了 HAL 库进行串口通信。在 STM32 的主循环中，通过 HAL_UART_Receive() 函数来接收串口数据并通过 HAL_UART_Transmit() 函数来发送串口数据。