const uint32_t SystemFrequency_SysClk = SYSCLK_FREQ_72MHz;什么意思

这行代码定义了一个名为 SystemFrequency_SysClk 的常量，其值为 72000000，也就是 STM32F1 系列微控制器的系统时钟频率，单位为 Hz。SYSCLK_FREQ_72MHz 是一个宏定义，表示 72MHz，用于提高代码的可读性和可维护性。在 STM32F1 系列微控制器中，系统时钟可以通过各种方式配置，该常量的值取决于实际配置。

相关问题

基于STM32采集DHT11信息，通过广和通L610通讯模组上报到腾讯云平台代码

以下是基于STM32采集DHT11信息，通过广和通L610通讯模组上报到腾讯云平台的示例代码：

#include "main.h"
#include "dht11.h"
#include "string.h"
#include "stdio.h"

#define DHT11_PORT GPIOB
#define DHT11_PIN GPIO_PIN_6

#define L610_TX_PORT GPIOA
#define L610_TX_PIN GPIO_PIN_2
#define L610_RX_PORT GPIOA
#define L610_RX_PIN GPIO_PIN_3

#define L610_BUF_SIZE 256

UART_HandleTypeDef huart1;

uint8_t l610_buf[L610_BUF_SIZE];
uint8_t l610_buf_len = 0;

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)
  {
    DHT11_Data_TypeDef dht11_data;
    DHT11_Read_Data(&dht11_data, DHT11_PORT, DHT11_PIN);
    uint8_t temp = dht11_data.temp_integral;
    uint8_t humi = dht11_data.humi_integral;

    char msg[128];
    sprintf(msg, "{\"temp\":%d,\"humi\":%d}", temp, humi);

    HAL_UART_Transmit(&huart1, (uint8_t *)"AT+QHTTPCFG=\"requestheader\",1\r\n", strlen("AT+QHTTPCFG=\"requestheader\",1\r\n"), 1000);
    HAL_UART_Transmit(&huart1, (uint8_t *)"AT+QHTTPURL=50,10\r\n", strlen("AT+QHTTPURL=50,10\r\n"), 1000);
    HAL_UART_Transmit(&huart1, (uint8_t *)"httpbin.org\r\n", strlen("httpbin.org\r\n"), 1000);
    HAL_UART_Transmit(&huart1, (uint8_t *)"AT+QHTTPPOST=34,80,\"application/json\"\r\n", strlen("AT+QHTTPPOST=34,80,\"application/json\"\r\n"), 1000);
    HAL_UART_Transmit(&huart1, (uint8_t *)msg, strlen(msg), 1000);
    HAL_UART_Transmit(&huart1, (uint8_t *)"\r\n", 2, 1000);

    uint32_t start_time = HAL_GetTick();
    uint32_t timeout = 10000; // 10 seconds
    while (HAL_GetTick() - start_time < timeout)
    {
      if (l610_buf_len > 0)
      {
        if (strstr((const char *)l610_buf, "+QHTTPPOST: 200"))
        {
          HAL_UART_Transmit(&huart1, l610_buf, l610_buf_len, 1000);
          l610_buf_len = 0;
          break;
        }
        else
        {
          l610_buf_len = 0;
        }
      }
    }

    HAL_Delay(30000); // 30 seconds
  }
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
  if (huart->Instance == USART1)
  {
    if (l610_buf_len < L610_BUF_SIZE)
    {
      l610_buf[l610_buf_len++] = huart->Instance->DR & 0xff;
    }
  }
}

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

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                              | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSE;
  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();
  }
  HAL_UART_Receive_IT(&huart1, l610_buf, 1);
}

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

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_1, GPIO_PIN_RESET);

  /*Configure GPIO pin : PA1 */
  GPIO_InitStruct.Pin = GPIO_PIN_1;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin : PB6 */
  GPIO_InitStruct.Pin = GPIO_PIN_6;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /*Configure GPIO pin : PA2 */
  GPIO_InitStruct.Pin = L610_TX_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF1_USART2;
  HAL_GPIO_Init(L610_TX_PORT, &GPIO_InitStruct);

  /*Configure GPIO pin : PA3 */
  GPIO_InitStruct.Pin = L610_RX_PIN;
  GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
  GPIO_InitStruct.Alternate = GPIO_AF1_USART2;
  HAL_GPIO_Init(L610_RX_PORT, &GPIO_InitStruct);
}

这段代码使用了 STM32 HAL 库和广和通 L610 通讯模组，需要在 CubeMX 中配置相应的引脚和串口。在主循环中，首先读取 DHT11 温湿度传感器的数据，然后使用 sprintf 函数将温湿度数据格式化成 JSON 格式的字符串。接着使用 HAL_UART_Transmit 函数发送 HTTP POST 请求到腾讯云平台。在发送请求后，使用 HAL_UART_Receive_IT 函数启动串口接收中断，并在回调函数 HAL_UART_RxCpltCallback 中获取 L610 返回的数据。如果接收到了包含 "+QHTTPPOST: 200" 的响应，则说明数据上传成功，可以进行下一次数据采集和上传。

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);
}