esp32和stm32串口通信

ESP32和STM32之间的串口通信可以通过以下步骤实现：

1. 首先，确定通信的波特率、数据位、停止位和校验位等参数。

2. 在ESP32和STM32上分别配置串口通信模块，设置相应的参数。在ESP32上，可以使用ESP-IDF中提供的串口通信API（如uart_driver_install、uart_param_config等）进行配置，在STM32上，可以使用HAL库中提供的串口通信API进行配置。

3. 在ESP32和STM32上编写程序，实现数据的发送和接收。在ESP32上，可以使用uart_write_bytes函数向串口发送数据，使用uart_read_bytes函数从串口接收数据；在STM32上，可以使用HAL库中提供的USART_SendData和USART_ReceiveData函数进行数据的发送和接收。

4. 在程序中添加适当的延时或者使用中断方式进行数据的处理，以确保数据的可靠传输。

下面是ESP32和STM32之间串口通信的示例代码：

ESP32代码：

#include "driver/uart.h"

#define UART_TX_PIN 17
#define UART_RX_PIN 16

void app_main()
{
    uart_config_t uart_config = {
        .baud_rate = 9600,
        .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_2, &uart_config);
    uart_set_pin(UART_NUM_2, UART_TX_PIN, UART_RX_PIN, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
    uart_driver_install(UART_NUM_2, 1024, 0, 0, NULL, 0);

    uint8_t data[] = "Hello, STM32!";
    while (1) {
        uart_write_bytes(UART_NUM_2, (const char *)data, sizeof(data));
        vTaskDelay(1000 / portTICK_PERIOD_MS);
    }
}

STM32代码：

#include "stm32f4xx_hal.h"
#include "string.h"

UART_HandleTypeDef huart2;

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);

int main(void)
{
    HAL_Init();
    SystemClock_Config();
    MX_GPIO_Init();
    MX_USART2_UART_Init();

    uint8_t data[20];
    memset(data, 0, sizeof(data));
    while (1)
    {
        HAL_UART_Receive(&huart2, data, sizeof(data), 1000);
        HAL_UART_Transmit(&huart2, data, sizeof(data), 1000);
    }
}

void SystemClock_Config(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    __HAL_RCC_PWR_CLK_ENABLE();
    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
    RCC_OscInitStruct.HSEState = RCC_HSE_ON;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
    RCC_OscInitStruct.PLL.PLLM = 8;
    RCC_OscInitStruct.PLL.PLLN = 336;
    RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
    RCC_OscInitStruct.PLL.PLLQ = 7;
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    {
        Error_Handler();
    }
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;
    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
    {
        Error_Handler();
    }
}

static void MX_USART2_UART_Init(void)
{
    huart2.Instance = USART2;
    huart2.Init.BaudRate = 9600;
    huart2.Init.WordLength = UART_WORDLENGTH_8B;
    huart2.Init.StopBits = UART_STOPBITS_1;
    huart2.Init.Parity = UART_PARITY_NONE;
    huart2.Init.Mode = UART_MODE_TX_RX;
    huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart2.Init.OverSampling = UART_OVERSAMPLING_16;
    if (HAL_UART_Init(&huart2) != HAL_OK)
    {
        Error_Handler();
    }
}

static void MX_GPIO_Init(void)
{
    __HAL_RCC_GPIOA_CLK_ENABLE();
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    GPIO_InitStruct.Pin = GPIO_PIN_2|GPIO_PIN_3;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF7_USART2;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}