STM32脱坑【Day 7】

目标：实现串口收发通信并控制板上硬件资源。

主机：电脑；从机：开发板

串口调试助手：XCOM V2.6

实验准备：参考文章STM32串口通信详解_rivencode的博客-优快云博客

本次实验硬件平台是Nucleo-F302R8开发板，软件平台为：STM32CubeMx&CubeIDE

首先是根据板子原理图找到板载串口号，确认为PA2(USART_TX)和PA3(USART_RX);在CubeMx中将PA2、PA3设置为UASRT2如图：

然后再Connectivity中设置串口：

记下这里的波特率，串口调试助手波特率同此处一致

保存并生成代码，截取串口生成代码：

 主函数代码块

#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 huart2;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* 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_USART2_UART_Init();
  /* USER CODE BEGIN 2 */
//char message[]="Hello World!"; //从机向主机发�??
  uint8_t receivedata[2];

  /* USER CODE END 2 */

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

    /* USER CODE BEGIN 3 */
	  //从机向主机发�??
	 /* HAL_UART_Transmit(&huart2, (uint8_t*)message, strlen(message), 100);
	  HAL_Delay(1000);*/
	  //从机接收主机
	  HAL_UART_Receive(&huart2, receivedata, 2, HAL_MAX_DELAY);
	  //接收到的信息返回到从�??
	  HAL_UART_Transmit(&huart2, receivedata, 2, 100);

	 //利用接收数据控制小灯
	  GPIO_PinState state = GPIO_PIN_RESET;
	  if(receivedata[1]=='1')
	  {
		  state=GPIO_PIN_SET;

	  }
	  if(receivedata[0]=='R')
		  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_13, state);
	  if(receivedata[0]=='0')
		  state=GPIO_PIN_SET;
	  if(receivedata[1]=='R')
		  HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_13);
  }
  /* USER CODE END 3 */
}

定义收发数据数组receivedata[2]，使用HAL_UART_Transmit()函数实现从机向主机发送数据，HAL_UART_Receive()函数接收主机发来的数据。

 然后将数据指令与LED状态进行匹配，实现控制小灯的效果。

发送R1时，LED点亮；发送R0，LED熄灭

 

 本实验实现了基本的串口收发和外设控制，但是这种控制方式对系统资源占用较大，CPU时钟在检测串口工作状态，资源利用率很低，因此有必要引入中断提高串口收发效率。