自行车码表

一、      实验目的和要求

1.    理解MCU上电启动过程；

2.    掌握使用Cube库来编写STM32裸机程序的方法；

3.    掌握使用Cube库来编写GPTO和UART程序的方法；

4.    掌握使用Cube库来编写中断响应程序的方法；

5.    理解前后台程序模式

6.    掌握在STM32F103上编写裸机程序并下载运行的方法。

 

二、      实验器材

1.    STM32F103核心板一块；

2.    MicroUSB线一根；

3.    STLink板或USB串口板一块；

4.    交叉编译软件

 

三、      实验内容和原理

1．编写Cube程序，配置UART0为9600，8n1，上电后向串口输出“Hello”，在PC上通过串口软件观察结果

2．通过面包板在PA11和PA12各连接一个按钮开关到地

3．编写Cube程序，配置PA11和PA12为内部上拉到输入模式，在main()函数循环检测PA11按钮按下，并在按钮按下时在串口输出Pressed。

4．编写Cube程序，配置PA12下降沿触发中断，程序中设置两个全局变量，一个为计数器，一个为标识。当中断触发时，计数器加1，并设置标识。在主循环中判断标识，如果标识置位则清除标识并通过串口输出计数值；

5．编写Cube程序，开启定时器为200ms中断一次，中断触发时设置标识，主循环根据这个标识来做串口输出（取消4的串口输出）；

6．编写完整的码表程序，PA12的按钮标识车轮转了一圈，通过计数器可以得到里程，通过定时器中断得到的时间可以计算出速度；PA的按钮切换模式，模式一在串口输出里程，模式二在串口输出速度。

四、      实验过程和数据记录

1.    下列图片为实物连接图



其中串口使用PA9，PA10；GPIO使用PA11，PA12，分别连接按钮。黑线接地。

 

2.    在Cube软件中配置UART0的波特率为9600, 8n1，然后向串口输出Hello，通过Mac上的串口软件观察结果。

a.    下图为配置图片，将波特率设置为9600，8n1.





b.    配置完成后，我们就可以用HAL_UART_Transmit和HAL_UART_Receive两个函数来进行串口的收发数据。使用GNUC需要重写__io_putchar和fputc函数，我们通过宏定义来完成。



c.    测试串口输出，在while循环前添加printf函数来输出Hello



d.    下面是实验结果展示图



3.    编写Cube程序，配置PA11和PA12为内部上拉到输入模式，在main()函数循环检测PA11按钮按下，并在按钮按下时在串口输出Pressed
a.    首先配置PA11和PA12为内部上拉到输入模式，如下图所示





 

b.    在while循环中写出如果按下按钮，则在串口输出Pressed字样，循环代码如下图所示



c.    下面是输出图示



4.    编写Cube程序，配置PA12下降沿触发中断，程序中设置两个全局变量，一个为计数器，一个为标识。当中断触发时，计数器加1，并设置标识。在主循环中判断标识，如果标识置位则清除标识并通过串口输出计数值
a.    配置PA12下降沿触发中断，配置过程如下







b.    设置两个全局变量stopwatch_counter和stopwatch_flag，并且实现HAL_GPIO_EXTI_Callback(unit16_tGPIO_Pin)函数，函数实现如下



c.    在while循环中，通过判断全局变量stopwatch_flag的值，来判断中断是否发生，代码实现如下



d.    成功编译之后下载到板子上，运行结果如下图所示


 

5.    编写Cube程序，开启定时器为200ms中断一次，中断触发时设置标识，主循环根据这个标识来做串口输出（取消4的串口输出）

a.    配置时钟信息如下







b.    实现HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)函数，用来设置标识符



c.    在main函数初始化定时器，并且根据stopwatch_flag来判断中断是够发生。实现代码如下



d.    在串口软件监测到如下结果



 

6.    编写完整的码表程序，PA12的按钮标识车轮转了一圈，通过计数器可以得到里程，通过定时器中断得到的时间可以计算出速度；PA的按钮切换模式，模式一在串口输出里程，模式二在串口输出速度。

a.    在计算速度和里程的过程中，里程默认中断一次为1m，速度计算公式为stopwatch_mile*18/stopwatch_time，stopewatch_time为添加的全局变量，表示定时器的中断次数。

b.    完整代码如下

/**   ******************************************************************************   * File Name          : main.c   * Description        : Main program body   ******************************************************************************   *   * COPYRIGHT(c) 2016 STMicroelectronics   *   * Redistribution and use in source and binary forms, with or without modification,   * are permitted provided that the following conditions are met:   *   1. Redistributions of source code must retain the above copyright notice,   *      this list of conditions and the following disclaimer.   *   2. Redistributions in binary form must reproduce the above copyright notice,   *      this list of conditions and the following disclaimer in the documentation   *      and/or other materials provided with the distribution.   *   3. Neither the name of STMicroelectronics nor the names of its contributors   *      may be used to endorse or promote products derived from this software   *      without specific prior written permission.   *   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.   *   ******************************************************************************   */ /* Includes ------------------------------------------------------------------*/ #include "stm32f1xx_hal.h"   /* USER CODE BEGIN Includes */   /* USER CODE END Includes */   /* Private variables ---------------------------------------------------------*/ TIM_HandleTypeDef htim2;   UART_HandleTypeDef huart1;   /* USER CODE BEGIN PV */ /* Private variables ---------------------------------------------------------*/   int stopwatch_counter; int stopwatch_flag; int stopwatch_time; int stopwatch_mode;   /* USER CODE END PV */   /* Private function prototypes -----------------------------------------------*/ void SystemClock_Config(void); static void MX_GPIO_Init(void); static void MX_USART1_UART_Init(void); static void MX_TIM2_Init(void);   /* USER CODE BEGIN PFP */ /* Private function prototypes -----------------------------------------------*/ #ifdef __GNUC__ /* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf    set to 'Yes') calls __io_putchar() */ #define PUTCHAR_PROTOTYPE int __io_putchar(int ch) #else #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f) #endif /* __GNUC__ */   /* USER CODE END PFP */   /* USER CODE BEGIN 0 */   /* USER CODE END 0 */   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();     /* Configure the system clock */   SystemClock_Config();     /* Initialize all configured peripherals */   MX_GPIO_Init();   MX_USART1_UART_Init();   MX_TIM2_Init();     /* USER CODE BEGIN 2 */             GPIO_PinState key;             HAL_TIM_Base_Start_IT(&htim2);             printf("Hello\n\r");                         double mile = 0;             double speed = 0;                 /* USER CODE END 2 */     /* Infinite loop */   /* USER CODE BEGIN WHILE */               while (1)   {   /* USER CODE END WHILE */     /* USER CODE BEGIN 3 */                                                 key = HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_11);                         if (key == GPIO_PIN_RESET)                         {                                     stopwatch_mode = !stopwatch_mode;                         }                         if (stopwatch_flag == 1)                         {                                     stopwatch_flag = 0;                                                                         mile = stopwatch_counter * 1;                                     if (stopwatch_mode == 0)                                     {                                                 printf("Current Mile: %f\n\r", mile);                                     }                                     else                                     {                                                 speed = stopwatch_counter  / stopwatch_time;                                                 printf("Current Speed: %1f\n\r", speed);                                     }                         }                         HAL_Delay(100);                             }   /* USER CODE END 3 */   }   /** System Clock Configuration */ void SystemClock_Config(void) {     RCC_OscInitTypeDef RCC_OscInitStruct;   RCC_ClkInitTypeDef RCC_ClkInitStruct;     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;   RCC_OscInitStruct.HSIState = RCC_HSI_ON;   RCC_OscInitStruct.HSICalibrationValue = 16;   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;   HAL_RCC_OscConfig(&RCC_OscInitStruct);     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;   HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0);     HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);     HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);     /* SysTick_IRQn interrupt configuration */   HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0); }   /* TIM2 init function */ void MX_TIM2_Init(void) {     TIM_ClockConfigTypeDef sClockSourceConfig;   TIM_MasterConfigTypeDef sMasterConfig;     htim2.Instance = TIM2;   htim2.Init.Prescaler = 8000;   htim2.Init.CounterMode = TIM_COUNTERMODE_UP;   htim2.Init.Period = 199;   htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;   HAL_TIM_Base_Init(&htim2);     sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;   HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig);     sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;   sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;   HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig);   }   /* USART1 init function */ void MX_USART1_UART_Init(void) {     huart1.Instance = USART1;   huart1.Init.BaudRate = 9600;   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;   HAL_UART_Init(&huart1);   }   /** Configure pins as         * Analog         * Input         * Output         * EVENT_OUT         * EXTI */ void MX_GPIO_Init(void) {     GPIO_InitTypeDef GPIO_InitStruct;     /* GPIO Ports Clock Enable */   __HAL_RCC_GPIOA_CLK_ENABLE();     /*Configure GPIO pin : PA11 */   GPIO_InitStruct.Pin = GPIO_PIN_11;   GPIO_InitStruct.Mode = GPIO_MODE_INPUT;   GPIO_InitStruct.Pull = GPIO_PULLUP;   HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);     /*Configure GPIO pin : PA12 */   GPIO_InitStruct.Pin = GPIO_PIN_12;   GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;   GPIO_InitStruct.Pull = GPIO_PULLUP;   HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);     /* EXTI interrupt init*/   HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0, 0);   HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);   }   /* USER CODE BEGIN 4 */ PUTCHAR_PROTOTYPE {   /* Place your implementation of fputc here */   /* e.g. write a character to the USART1 and Loop until the end of transmission */   HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);     return ch; }   void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {             if (GPIO_Pin == GPIO_PIN_12)             {                         stopwatch_counter += 1; //                      stopwatch_flag = 1;             } }   void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {             if (htim->Instance == TIM2)             {                         stopwatch_flag = 1;                         stopwatch_time += 1;             }             }     /* USER CODE END 4 */   #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,     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */   /* USER CODE END 6 */   }   #endif   /**   * @}   */   /**   * @} */   /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

c.    下面是实验结果图展示



 

7.    扩展内容

a.    扩展内容由于工程具有完整性，故统一完成如下

b.    Main函数中代码较为简单，为休眠操作，由于SysTick中断也会终止休眠，故应该关掉中断。

int main(void) {   HAL_Init();     /* Configure the system clock */   SystemClock_Config();     /* Initialize all configured peripherals */   MX_GPIO_Init();   MX_USART1_UART_Init();   MX_TIM2_Init();     /* USER CODE BEGIN 2 */             GPIO_PinState key;             HAL_TIM_Base_Start_IT(&htim2);             printf("Hello\n\r");               /* USER CODE END 2 */   while (1)   {   /* USER CODE END WHILE */     /* USER CODE BEGIN 3 */                                                 HAL_SuspendTick();                         __HAL_RCC_PWR_CLK_ENABLE();                         HAL_PWR_EnterSLEEPMode(PWR_MAINREGULATOR_ON, PWR_SLEEPENTRY_WFI);                         HAL_ResumeTick();   }   /* USER CODE END 3 */   }

c.    下面是中断处理函数的修改

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {                                     double mile = 0;             double speed = 0;                                     if (htim->Instance == TIM2)             { //                      stopwatch_flag = 1;                         stopwatch_time += 1;                                                 mile = stopwatch_counter*1;                         if (stopwatch_mode == 0)                         {                                     printf("Current Mile: %f\n\r", mile);                         }                         else                         {                                     speed = (double)stopwatch_counter / stopwatch_time;                                     printf("Current Speed: %1f\n\r", speed);                         }             }             }

           

d.    下面是实验结果图



可以看出和之前实验的输出结果相类似，实验成功。