【RoboMaster】一次搞定最難理解的DMA機制！【STM32】

同步博客地址：從STM32開始的RoboMaster生活：進階篇 IV [DMA]

項目&教程倉庫：-STM32-RoboMaster-

---

1.0 什麼是DMA

1.1 DMA的定義

Direct Memory Access：直接存儲器訪問 是所有現代計算設備的重要特色，它允許不同速度的硬件裝置來溝通，而不需要依賴於CPU的大量中斷負載。否則，CPU需要從來源把每一片段的資料複製到暫存器，然後把它們再次寫回到新的地方。在這個時間中，CPU對於其他的工作來說就無法使用。DMA傳輸將數據從一個地址空間複製到另外一個地址空間。當CPU初始化這個傳輸動作，傳輸動作本身是由DMA控制器來實行和完成。典型的例子就是移動一個外部內存的區塊到芯片內部更快的內存區。像是這樣的操作並沒有讓處理器工作拖延，反而可以被重新排程去處理其他的工作。DMA傳輸是高效能嵌入式系統算法和網絡最關鍵的部分。

從上圖可以看出，DMA和CPU是同等地位的，CPU能進行的數據轉移操作，DMA都能做，或者說，DMA就是隻能做數據轉移操作的迷你CPU。

如果要簡單理解的話，DMA就是CPU小弟，當CPU覺得把一大串數據轉移到另一個地方這種任務太麻煩，還有更重要的事情需要做的時候，就可以把這個任務丟給DMA去幹，DMA幹完或者出問題了跟CPU說一聲就行了。

1.2 DMA的內部結構

• STM32 --> DMA --> Stream --> Channel
  • STM32F4家族擁有兩個DMA，其中只有DMA2能夠進行M2M操作（稍後會講）。
  • 每個DMA一般擁有8個Stream。
  • 每個Stream有多個Channel選項，但是一次只能進行一個Channel的傳輸，具體的配置與選項請參考芯片對應的數據手冊。

2.0 什麼情況下使用DMA？

2.1 UART

• 這是最常見的使用情況，當有大量的數據從UART讀入或者寫入的時候，DMA將CPU解放出來，然後自己單幹，讓CPU處理更重要的事情。

2.2 ADC

• 一般在需要ADC時的通道掃描模式下，需要DMA來處理，本章不講解這部分，放到後面專門講ADC的篇章。

2.3 SD

• 需要大量往SD裏面讀寫數據的時候一般也用DMA來處理，本章不講解這部分。

3.0 DMA的使用方法

3.1 傳輸方向

• P2P
  • Peripheral to Peripheral：從外設到外設 在RM中暫時用不上，不講解
• P2M
  • Peripheral to Memory：從外設到內存 當傳感器從UART傳來數據的時候用
• M2P
  • Memory to Peripheral：從內存到外設 從UART傳出數據控制執行器的時候用
• M2M
  • Memory to Memory：從內存到內存 MCU內部的數據轉移，常見於Buffer之間互相轉移數據，或者從Buffer讀寫數據
  • 只有DMA2能夠執行M2M操作。

3.2 特殊選項

• First In First Out是STM32裏面的DMA的特殊功能，但是一般來說，RM就算不用FIFO，DMA也能完美處理數據，所以暫時不需要，也同樣不講解。

3.3 傳輸模式

3.3.1 Normal Mode

• 常用的默認模式，在該模式下，任務完成後就停止DMA，如果還需要用到DMA，需要再次手動啓動。

3.3.2 Circular Mode / Continuous Mode

• 可選模式，在該模式下，任務完成後，DMA的Buffer清零，再次執行任務。也就是說，永遠重複執行下去，除非手動停止。

3.4 傳輸方式

3.4.1 DMA泛用方法（需要用到寄存器）

3.4.1.1 Polling

需要注意的是，DMA的Polling其實根本毫無意義，因爲在這個過程中，CPU還是全程參與了，並沒有解放CPU，所以，雖然這種方法我還是列出來了，但是除了Debug時可能會用到，其他情況下建議不要用。

HAL_StatusTypeDef HAL_DMA_Start(DMA_HandleTypeDef *hdma, uint32_t SrcAddress, uint32_t	DstAddress, uint32_t DataLength);

• 參數
  • hdma：指向DMA Stream配置結構體
  • SrcAddress：需要傳輸的數據的地址
  • DstAddress：數據傳輸到的目標地址
  • DataLength：傳輸的數據大小
• 返回值
  • HAL_StatusTypeDef：如果傳輸配置成功，返回HAL_OK；如果該DMA Stream正在被佔用，返回HAL_BUSY

---

huart.Instance->CR3|=USART_CR3_DMAT;

• 通過修改CR3寄存器對應的bit，開啓DMA傳輸

---

HAL_StatusTypeDef HAL_DMA_PollForTransfer(DMA_HandleTypeDef *hdma, HAL_DMA_LevelCompleteTypeDef CompleteLevel, uint32_t Timeout);

• 參數
  • hdma：指向DMA Stream配置結構體
  • CompleteLevel：指定DMA的完成程度
  • Timeout：傳輸的最大時限
• 返回值
  • HAL_StatusTypeDef：如果傳輸成功，返回HAL_OK；如果傳輸出錯，返回HAL_ERROR；如果傳輸超過最大時限，返回HAL_TIMEOUT

---

huart.Instance->CR3&=~USART_CR3_DMAT;

• 通過修改CR3寄存器對應的bit，結束DMA傳輸

3.4.1.2 Interrupt

HAL_StatusTypeDef HAL_DMA_Start_IT(DMA_HandleTypeDef *hdma, uint32_t SrcAddress, uint32_t	DstAddress, uint32_t DataLength);

• 參數
  • hdma：指向DMA Stream配置結構體
  • SrcAddress：需要傳輸的數據的地址
  • DstAddress：數據傳輸到的目標地址
  • DataLength：傳輸的數據大小
• 返回值
  • HAL_StatusTypeDef：如果傳輸配置成功，返回HAL_OK；如果該DMA Stream正在被佔用，則返回HAL_BUSY

---

huart.Instance->CR3|=USART_CR3_DMAT;

• 通過修改CR3寄存器對應的bit，開啓DMA傳輸

---

void XferCpltCallback(DMA_HandleTypeDef *hdma){
    ......
}

• 在寫代碼的時候，在main.c中創建XferCpltCallback函數
• 在該函數中填寫DMA傳輸結束後，需要執行的代碼

---

huart.Instance->CR3&=~USART_CR3_DMAT;

• 通過修改CR3寄存器對應的bit，結束DMA傳輸

3.4.2 UART特化方法（全HAL庫實現）

HAL_StatusTypeDef HAL_UART_Transmit_DMA(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size);

• 參數
  • huart：指向UART引腳配置結構體
  • pData：指向需要傳輸的數據
  • Size：傳輸數據的大小
• 返回值
  • HAL_StatusTypeDef：如果傳輸配置成功，返回HAL_OK；如果傳輸出錯，返回HAL_ERROR；如果該DMA Stream正在被佔用，則返回HAL_BUSY

---

HAL_StatusTypeDef HAL_UART_Receive_DMA(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size);

• 參數
  • huart：指向UART引腳配置結構體
  • pData：指向需要傳輸的數據
  • Size：傳輸數據的大小
• 返回值
  • HAL_StatusTypeDef：如果傳輸配置成功，返回HAL_OK；如果傳輸出錯，返回HAL_ERROR；如果該DMA Stream正在被佔用，則返回HAL_BUSY

---

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart){
	......
}

• 在寫代碼的時候，在main.c中創建HAL_UART_TxCpltCallback函數
• 在該函數中填寫UART發送結束後，需要執行的代碼

---

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
	......
}

• 在寫代碼的時候，在main.c中創建HAL_UART_RxCpltCallback函數
• 在該函數中填寫UART接收結束後，需要執行的代碼

4.0 練習項目

4.1 項目簡介

• 一鍵發送信息：按下用戶自定義按鈕，就從UART發送出預先設定好的信息，完成後在板子上亮紅燈0.2s。
• 鍵盤迴響：按下鍵盤，從STM32返回對應的字符，完成後在板子上亮綠燈0.2s。然後，再加上上面一鍵發送信息的功能。

4.2 項目代碼

完整的工程文件可以在這裏找到！

4.2.1 一鍵發送信息

• DMA泛用方法 Polling

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "string.h"
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart7;
DMA_HandleTypeDef hdma_uart7_tx;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_UART7_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
char msg[]="\r\n"
           "                                    %@@@@@@@#\r\n"
           "                      .(&@&,        &@@@@@@@%        *@@&(\r\n"
           "                   %@@@@@@@@%%&@@@@@@@@@@@@@@@@@@@&%&@@@@@@@@#\r\n"
           "                    &@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@/\r\n"
           "           ,.    .&@@@@@@@@@@@@@&(.           ,(&@@@@@@@@@@@@@&.    .,\r\n"
           "          &@@@@&@@@@@@@@@@@&,   ###%#%%%%#%%%####   *&@@@@@@@@@@@&@@@@%\r\n"
           "        /@@@@@@@@@@@@@@@&          ,@@@@@@@@&.         .&@@@@@@@@@@@@@@@,\r\n"
           "       (&@@@@@@@@@@@@@#             (@@@@@@@/             %@@@@@@@@@@@@@&*\r\n"
           "           &@@@@@@@@&.        ,%@@@@&@@@@@@@&@@@&%,        ,&@@@@@@@@%\r\n"
           "          /@@@@@@@@%       #@@@@@(  *@@@@@@&,  %@@@@&(       &@@@@@@@@/\r\n"
           "         .&@@@@@@@%      #@@@@@%    *@@@@@@&,    &@@@@@#      &@@@@@@@&.                #  \"There is no truth in flesh,     only betrayal.\"\r\n"
           "    ,%%%%&@@@@@@@@*     &@@@@@%     *@@@@@@&,     %@@@@@%     ,@@@@@@@@&%%%%            #  \"There is no strength in flesh,  only weakness.\"\r\n"
           "    /@@@@@@@@@@@@&.    #@@@@@@,     *@@@@@@&,     ,@@@@@@(    .&@@@@@@@@@@@&,           #  \"There is no constancy in flesh, only decay   .\"\r\n"
           "    /@@@@@@@@@@@@&     %@@@@@@,     *@@@@@@&,     ,@@@@@@#    .&@@@@@@@@@@@&,           #  \"There is no certainty in flesh, but death    .\"\r\n"
           "    *&@@@@@@@@@@@&,    .@@@@@@#     *@@@@@@&,     %@@@@@&     ,@@@@@@@@@@@@&.           #                                 — Credo Omnissiah\r\n"
           "         .&@@@@@@@#     .&@@@@@(    *@@@@@@&,    %@@@@@&      %@@@@@@@&.\r\n"
           "          (@@@@@@@@(      ,&@@@@&.  *@@@@@@&,  *&@@@@%.      #@@@@@@@@(                 Welcome back to Adeptus Mechanicus, Alchemic Ronin!\r\n"
           "           %@@@@@@@@%        .%@@@@&%@@@@@@@%&@@@@#.        %@@@@@@@@%\r\n"
           "       .(&@@@@@@@@@@@@,            *%@@@@@@@%*            (@@@@@@@@@@@@&/\r\n"
           "        %@@@@@@@@@@@@@@@/         .(@@@@@@@@@(.         #@@@@@@@@@@@@@@@#\r\n"
           "         .&@@@@@@@@@@@@@@@@(    ,***************,    #&@@@@@@@@@@@@@@@&.\r\n"
           "           %(    #@@@@@@@@@@@@@%*.             ./&@@@@@@@@@@@@@/   .##\r\n"
           "                   .&@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%.\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@(\r\n"
           "                   &@@@@@@@@@&@@@@@@@@@@@@@@@@@@@@@&@@@@@@@@@%\r\n"
           "                      /&@@@/      .*&@@@@@@@&,.      (@@@&/\r\n"
           "                                    %@@@@@@@#\r\n"
           "                                    .,,,,,,,.\r\n"
           "\r\n";
/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_UART7_Init();
  /* USER CODE BEGIN 2 */
  HAL_GPIO_WritePin(LD_RED_GPIO_Port,LD_RED_Pin,GPIO_PIN_SET);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage 
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
  /** 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();
  }
}

/**
  * @brief UART7 Initialization Function
  * @param None
  * @retval None
  */
static void MX_UART7_Init(void)
{

  /* USER CODE BEGIN UART7_Init 0 */

  /* USER CODE END UART7_Init 0 */

  /* USER CODE BEGIN UART7_Init 1 */

  /* USER CODE END UART7_Init 1 */
  huart7.Instance = UART7;
  huart7.Init.BaudRate = 115200;
  huart7.Init.WordLength = UART_WORDLENGTH_8B;
  huart7.Init.StopBits = UART_STOPBITS_1;
  huart7.Init.Parity = UART_PARITY_NONE;
  huart7.Init.Mode = UART_MODE_TX_RX;
  huart7.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart7.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart7) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART7_Init 2 */

  /* USER CODE END UART7_Init 2 */

}

/** 
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void) 
{

  /* DMA controller clock enable */
  __HAL_RCC_DMA1_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA1_Stream1_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

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

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LD_RED_GPIO_Port, LD_RED_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin : Button_Pin */
  GPIO_InitStruct.Pin = Button_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(Button_GPIO_Port, &GPIO_InitStruct);

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

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI2_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(EXTI2_IRQn);

}

/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
	if(GPIO_Pin == Button_Pin){
		HAL_Delay(500);
		HAL_DMA_Start(&hdma_uart7_tx,(uint32_t)msg,(uint32_t)&huart7.Instance->DR,strlen(msg));
		huart7.Instance->CR3|=USART_CR3_DMAT;
		HAL_DMA_PollForTransfer(&hdma_uart7_tx,HAL_DMA_FULL_TRANSFER,HAL_MAX_DELAY);
		huart7.Instance->CR3&=~USART_CR3_DMAT;
		HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
		HAL_Delay(200);
		HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
	}
}
/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{ 
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

• DMA泛用方法 Interrupt

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "string.h"
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart7;
DMA_HandleTypeDef hdma_uart7_tx;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_UART7_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
char msg[]="\r\n"
           "                                    %@@@@@@@#\r\n"
           "                      .(&@&,        &@@@@@@@%        *@@&(\r\n"
           "                   %@@@@@@@@%%&@@@@@@@@@@@@@@@@@@@&%&@@@@@@@@#\r\n"
           "                    &@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@/\r\n"
           "           ,.    .&@@@@@@@@@@@@@&(.           ,(&@@@@@@@@@@@@@&.    .,\r\n"
           "          &@@@@&@@@@@@@@@@@&,   ###%#%%%%#%%%####   *&@@@@@@@@@@@&@@@@%\r\n"
           "        /@@@@@@@@@@@@@@@&          ,@@@@@@@@&.         .&@@@@@@@@@@@@@@@,\r\n"
           "       (&@@@@@@@@@@@@@#             (@@@@@@@/             %@@@@@@@@@@@@@&*\r\n"
           "           &@@@@@@@@&.        ,%@@@@&@@@@@@@&@@@&%,        ,&@@@@@@@@%\r\n"
           "          /@@@@@@@@%       #@@@@@(  *@@@@@@&,  %@@@@&(       &@@@@@@@@/\r\n"
           "         .&@@@@@@@%      #@@@@@%    *@@@@@@&,    &@@@@@#      &@@@@@@@&.                #  \"There is no truth in flesh,     only betrayal.\"\r\n"
           "    ,%%%%&@@@@@@@@*     &@@@@@%     *@@@@@@&,     %@@@@@%     ,@@@@@@@@&%%%%            #  \"There is no strength in flesh,  only weakness.\"\r\n"
           "    /@@@@@@@@@@@@&.    #@@@@@@,     *@@@@@@&,     ,@@@@@@(    .&@@@@@@@@@@@&,           #  \"There is no constancy in flesh, only decay   .\"\r\n"
           "    /@@@@@@@@@@@@&     %@@@@@@,     *@@@@@@&,     ,@@@@@@#    .&@@@@@@@@@@@&,           #  \"There is no certainty in flesh, but death    .\"\r\n"
           "    *&@@@@@@@@@@@&,    .@@@@@@#     *@@@@@@&,     %@@@@@&     ,@@@@@@@@@@@@&.           #                                 — Credo Omnissiah\r\n"
           "         .&@@@@@@@#     .&@@@@@(    *@@@@@@&,    %@@@@@&      %@@@@@@@&.\r\n"
           "          (@@@@@@@@(      ,&@@@@&.  *@@@@@@&,  *&@@@@%.      #@@@@@@@@(                 Welcome back to Adeptus Mechanicus, Alchemic Ronin!\r\n"
           "           %@@@@@@@@%        .%@@@@&%@@@@@@@%&@@@@#.        %@@@@@@@@%\r\n"
           "       .(&@@@@@@@@@@@@,            *%@@@@@@@%*            (@@@@@@@@@@@@&/\r\n"
           "        %@@@@@@@@@@@@@@@/         .(@@@@@@@@@(.         #@@@@@@@@@@@@@@@#\r\n"
           "         .&@@@@@@@@@@@@@@@@(    ,***************,    #&@@@@@@@@@@@@@@@&.\r\n"
           "           %(    #@@@@@@@@@@@@@%*.             ./&@@@@@@@@@@@@@/   .##\r\n"
           "                   .&@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%.\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@(\r\n"
           "                   &@@@@@@@@@&@@@@@@@@@@@@@@@@@@@@@&@@@@@@@@@%\r\n"
           "                      /&@@@/      .*&@@@@@@@&,.      (@@@&/\r\n"
           "                                    %@@@@@@@#\r\n"
           "                                    .,,,,,,,.\r\n"
           "\r\n";
/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_UART7_Init();
  /* USER CODE BEGIN 2 */
  HAL_GPIO_WritePin(LD_RED_GPIO_Port,LD_RED_Pin,GPIO_PIN_SET);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage 
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
  /** 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();
  }
}

/**
  * @brief UART7 Initialization Function
  * @param None
  * @retval None
  */
static void MX_UART7_Init(void)
{

  /* USER CODE BEGIN UART7_Init 0 */

  /* USER CODE END UART7_Init 0 */

  /* USER CODE BEGIN UART7_Init 1 */

  /* USER CODE END UART7_Init 1 */
  huart7.Instance = UART7;
  huart7.Init.BaudRate = 115200;
  huart7.Init.WordLength = UART_WORDLENGTH_8B;
  huart7.Init.StopBits = UART_STOPBITS_1;
  huart7.Init.Parity = UART_PARITY_NONE;
  huart7.Init.Mode = UART_MODE_TX_RX;
  huart7.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart7.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart7) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART7_Init 2 */

  /* USER CODE END UART7_Init 2 */

}

/** 
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void) 
{

  /* DMA controller clock enable */
  __HAL_RCC_DMA1_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA1_Stream1_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

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

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LD_RED_GPIO_Port, LD_RED_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin : Button_Pin */
  GPIO_InitStruct.Pin = Button_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(Button_GPIO_Port, &GPIO_InitStruct);

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

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI2_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(EXTI2_IRQn);

}

/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
	if(GPIO_Pin == Button_Pin){
		HAL_Delay(500);
		HAL_DMA_Start_IT(&hdma_uart7_tx,(uint32_t)msg,(uint32_t)&huart7.Instance->DR,strlen(msg));
		huart7.Instance->CR3|=USART_CR3_DMAT;
	}
}

void XferCpltCallback(DMA_HandleTypeDef *hdma){
	if(hdma->Instance == DMA1_Stream1){
		huart7.Instance->CR3&=~USART_CR3_DMAT;
		HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
		HAL_Delay(200);
		HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
	}
}
/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{ 
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

• UART特化方法

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "string.h"
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart7;
DMA_HandleTypeDef hdma_uart7_tx;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_UART7_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
char msg[]="\r\n"
           "                                    %@@@@@@@#\r\n"
           "                      .(&@&,        &@@@@@@@%        *@@&(\r\n"
           "                   %@@@@@@@@%%&@@@@@@@@@@@@@@@@@@@&%&@@@@@@@@#\r\n"
           "                    &@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@/\r\n"
           "           ,.    .&@@@@@@@@@@@@@&(.           ,(&@@@@@@@@@@@@@&.    .,\r\n"
           "          &@@@@&@@@@@@@@@@@&,   ###%#%%%%#%%%####   *&@@@@@@@@@@@&@@@@%\r\n"
           "        /@@@@@@@@@@@@@@@&          ,@@@@@@@@&.         .&@@@@@@@@@@@@@@@,\r\n"
           "       (&@@@@@@@@@@@@@#             (@@@@@@@/             %@@@@@@@@@@@@@&*\r\n"
           "           &@@@@@@@@&.        ,%@@@@&@@@@@@@&@@@&%,        ,&@@@@@@@@%\r\n"
           "          /@@@@@@@@%       #@@@@@(  *@@@@@@&,  %@@@@&(       &@@@@@@@@/\r\n"
           "         .&@@@@@@@%      #@@@@@%    *@@@@@@&,    &@@@@@#      &@@@@@@@&.                #  \"There is no truth in flesh,     only betrayal.\"\r\n"
           "    ,%%%%&@@@@@@@@*     &@@@@@%     *@@@@@@&,     %@@@@@%     ,@@@@@@@@&%%%%            #  \"There is no strength in flesh,  only weakness.\"\r\n"
           "    /@@@@@@@@@@@@&.    #@@@@@@,     *@@@@@@&,     ,@@@@@@(    .&@@@@@@@@@@@&,           #  \"There is no constancy in flesh, only decay   .\"\r\n"
           "    /@@@@@@@@@@@@&     %@@@@@@,     *@@@@@@&,     ,@@@@@@#    .&@@@@@@@@@@@&,           #  \"There is no certainty in flesh, but death    .\"\r\n"
           "    *&@@@@@@@@@@@&,    .@@@@@@#     *@@@@@@&,     %@@@@@&     ,@@@@@@@@@@@@&.           #                                 — Credo Omnissiah\r\n"
           "         .&@@@@@@@#     .&@@@@@(    *@@@@@@&,    %@@@@@&      %@@@@@@@&.\r\n"
           "          (@@@@@@@@(      ,&@@@@&.  *@@@@@@&,  *&@@@@%.      #@@@@@@@@(                 Welcome back to Adeptus Mechanicus, Alchemic Ronin!\r\n"
           "           %@@@@@@@@%        .%@@@@&%@@@@@@@%&@@@@#.        %@@@@@@@@%\r\n"
           "       .(&@@@@@@@@@@@@,            *%@@@@@@@%*            (@@@@@@@@@@@@&/\r\n"
           "        %@@@@@@@@@@@@@@@/         .(@@@@@@@@@(.         #@@@@@@@@@@@@@@@#\r\n"
           "         .&@@@@@@@@@@@@@@@@(    ,***************,    #&@@@@@@@@@@@@@@@&.\r\n"
           "           %(    #@@@@@@@@@@@@@%*.             ./&@@@@@@@@@@@@@/   .##\r\n"
           "                   .&@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%.\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@(\r\n"
           "                   &@@@@@@@@@&@@@@@@@@@@@@@@@@@@@@@&@@@@@@@@@%\r\n"
           "                      /&@@@/      .*&@@@@@@@&,.      (@@@&/\r\n"
           "                                    %@@@@@@@#\r\n"
           "                                    .,,,,,,,.\r\n"
           "\r\n";
/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_UART7_Init();
  /* USER CODE BEGIN 2 */
  HAL_GPIO_WritePin(LD_RED_GPIO_Port,LD_RED_Pin,GPIO_PIN_SET);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage 
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
  /** 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();
  }
}

/**
  * @brief UART7 Initialization Function
  * @param None
  * @retval None
  */
static void MX_UART7_Init(void)
{

  /* USER CODE BEGIN UART7_Init 0 */

  /* USER CODE END UART7_Init 0 */

  /* USER CODE BEGIN UART7_Init 1 */

  /* USER CODE END UART7_Init 1 */
  huart7.Instance = UART7;
  huart7.Init.BaudRate = 115200;
  huart7.Init.WordLength = UART_WORDLENGTH_8B;
  huart7.Init.StopBits = UART_STOPBITS_1;
  huart7.Init.Parity = UART_PARITY_NONE;
  huart7.Init.Mode = UART_MODE_TX_RX;
  huart7.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart7.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart7) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART7_Init 2 */

  /* USER CODE END UART7_Init 2 */

}

/** 
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void) 
{

  /* DMA controller clock enable */
  __HAL_RCC_DMA1_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA1_Stream1_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

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

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LD_RED_GPIO_Port, LD_RED_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin : Button_Pin */
  GPIO_InitStruct.Pin = Button_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(Button_GPIO_Port, &GPIO_InitStruct);

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

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI2_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(EXTI2_IRQn);

}

/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
	if(GPIO_Pin == Button_Pin){
		HAL_Delay(500);
		HAL_UART_Transmit_DMA(&huart7,(uint8_t*)msg,strlen(msg));
	}
}

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart){
	HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
	HAL_Delay(200);
	HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
}
/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{ 
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

4.2.2 鍵盤迴響

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "string.h"
#include "stdbool.h"
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
UART_HandleTypeDef huart7;
DMA_HandleTypeDef hdma_uart7_rx;
DMA_HandleTypeDef hdma_uart7_tx;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_UART7_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
char msg[]="\r\n"
           "                                    %@@@@@@@#\r\n"
           "                      .(&@&,        &@@@@@@@%        *@@&(\r\n"
           "                   %@@@@@@@@%%&@@@@@@@@@@@@@@@@@@@&%&@@@@@@@@#\r\n"
           "                    &@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@/\r\n"
           "           ,.    .&@@@@@@@@@@@@@&(.           ,(&@@@@@@@@@@@@@&.    .,\r\n"
           "          &@@@@&@@@@@@@@@@@&,   ###%#%%%%#%%%####   *&@@@@@@@@@@@&@@@@%\r\n"
           "        /@@@@@@@@@@@@@@@&          ,@@@@@@@@&.         .&@@@@@@@@@@@@@@@,\r\n"
           "       (&@@@@@@@@@@@@@#             (@@@@@@@/             %@@@@@@@@@@@@@&*\r\n"
           "           &@@@@@@@@&.        ,%@@@@&@@@@@@@&@@@&%,        ,&@@@@@@@@%\r\n"
           "          /@@@@@@@@%       #@@@@@(  *@@@@@@&,  %@@@@&(       &@@@@@@@@/\r\n"
           "         .&@@@@@@@%      #@@@@@%    *@@@@@@&,    &@@@@@#      &@@@@@@@&.                #  \"There is no truth in flesh,     only betrayal.\"\r\n"
           "    ,%%%%&@@@@@@@@*     &@@@@@%     *@@@@@@&,     %@@@@@%     ,@@@@@@@@&%%%%            #  \"There is no strength in flesh,  only weakness.\"\r\n"
           "    /@@@@@@@@@@@@&.    #@@@@@@,     *@@@@@@&,     ,@@@@@@(    .&@@@@@@@@@@@&,           #  \"There is no constancy in flesh, only decay   .\"\r\n"
           "    /@@@@@@@@@@@@&     %@@@@@@,     *@@@@@@&,     ,@@@@@@#    .&@@@@@@@@@@@&,           #  \"There is no certainty in flesh, but death    .\"\r\n"
           "    *&@@@@@@@@@@@&,    .@@@@@@#     *@@@@@@&,     %@@@@@&     ,@@@@@@@@@@@@&.           #                                 — Credo Omnissiah\r\n"
           "         .&@@@@@@@#     .&@@@@@(    *@@@@@@&,    %@@@@@&      %@@@@@@@&.\r\n"
           "          (@@@@@@@@(      ,&@@@@&.  *@@@@@@&,  *&@@@@%.      #@@@@@@@@(                 Welcome back to Adeptus Mechanicus, Alchemic Ronin!\r\n"
           "           %@@@@@@@@%        .%@@@@&%@@@@@@@%&@@@@#.        %@@@@@@@@%\r\n"
           "       .(&@@@@@@@@@@@@,            *%@@@@@@@%*            (@@@@@@@@@@@@&/\r\n"
           "        %@@@@@@@@@@@@@@@/         .(@@@@@@@@@(.         #@@@@@@@@@@@@@@@#\r\n"
           "         .&@@@@@@@@@@@@@@@@(    ,***************,    #&@@@@@@@@@@@@@@@&.\r\n"
           "           %(    #@@@@@@@@@@@@@%*.             ./&@@@@@@@@@@@@@/   .##\r\n"
           "                   .&@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@%.\r\n"
           "                    #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@(\r\n"
           "                   &@@@@@@@@@&@@@@@@@@@@@@@@@@@@@@@&@@@@@@@@@%\r\n"
           "                      /&@@@/      .*&@@@@@@@&,.      (@@@&/\r\n"
           "                                    %@@@@@@@#\r\n"
           "                                    .,,,,,,,.\r\n"
           "\r\n";
uint8_t data[1];
bool flag=false;
/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_UART7_Init();
  /* USER CODE BEGIN 2 */
	HAL_GPIO_WritePin(LD_RED_GPIO_Port,LD_RED_Pin,GPIO_PIN_SET);
	HAL_GPIO_WritePin(LD_GREEN_GPIO_Port,LD_GREEN_Pin,GPIO_PIN_SET);
	HAL_UART_Receive_DMA(&huart7,data,1);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
	while (1)
	{
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
	}
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage 
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
  /** 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();
  }
}

/**
  * @brief UART7 Initialization Function
  * @param None
  * @retval None
  */
static void MX_UART7_Init(void)
{

  /* USER CODE BEGIN UART7_Init 0 */

  /* USER CODE END UART7_Init 0 */

  /* USER CODE BEGIN UART7_Init 1 */

  /* USER CODE END UART7_Init 1 */
  huart7.Instance = UART7;
  huart7.Init.BaudRate = 115200;
  huart7.Init.WordLength = UART_WORDLENGTH_8B;
  huart7.Init.StopBits = UART_STOPBITS_1;
  huart7.Init.Parity = UART_PARITY_NONE;
  huart7.Init.Mode = UART_MODE_TX_RX;
  huart7.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart7.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart7) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN UART7_Init 2 */

  /* USER CODE END UART7_Init 2 */

}

/** 
  * Enable DMA controller clock
  */
static void MX_DMA_Init(void) 
{

  /* DMA controller clock enable */
  __HAL_RCC_DMA1_CLK_ENABLE();

  /* DMA interrupt init */
  /* DMA1_Stream1_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);
  /* DMA1_Stream3_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(DMA1_Stream3_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(DMA1_Stream3_IRQn);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_GPIOE_CLK_ENABLE();
  __HAL_RCC_GPIOF_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LD_RED_GPIO_Port, LD_RED_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(LD_GREEN_GPIO_Port, LD_GREEN_Pin, GPIO_PIN_RESET);

  /*Configure GPIO pin : Button_Pin */
  GPIO_InitStruct.Pin = Button_Pin;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  HAL_GPIO_Init(Button_GPIO_Port, &GPIO_InitStruct);

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

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

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI2_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(EXTI2_IRQn);

}

/* USER CODE BEGIN 4 */
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
	if(GPIO_Pin == Button_Pin){
		HAL_Delay(500);
		flag=true;
		HAL_UART_Transmit_DMA(&huart7,(uint8_t*)msg,strlen(msg));
	}
}

void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart){
	if(flag==true){
		flag=false;
		HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
		HAL_Delay(200);
		HAL_GPIO_TogglePin(LD_RED_GPIO_Port,LD_RED_Pin);
	}else{
		HAL_GPIO_TogglePin(LD_GREEN_GPIO_Port, LD_GREEN_Pin);
		HAL_Delay(200);
		HAL_GPIO_TogglePin(LD_GREEN_GPIO_Port, LD_GREEN_Pin);
	}
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart){
	HAL_UART_Transmit_DMA(&huart7,data,1);
	HAL_UART_Receive_DMA(&huart7,data,1);
}
/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
	/* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{ 
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

4.3 效果展示

• 因爲按鍵迴響已經包含了一鍵發送信息的功能，所以視頻部分就只錄了按鍵迴響的效果

http://player.bilibili.com/player.html?aid=97217251&cid=165950467&page=1