模块介绍：

接线：

VCC -- 3.3V 不能接5V，否则遮挡一次会触发3次中断

OUT -- PB14

测速原理：

cubeMX设置：

PB14设置为gpio中断

打开定时器2，时钟来源设置为内部时钟，设置溢出时间1s，计算公式为(psc+1)*(ARR+1)/72M。

打开定时器2中断，串口1中断和外部中断线（PB14）.

main.c

#include "main.h"
#include "tim.h"
#include "usart.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "motor.h"
#include "stdio.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 ---------------------------------------------------------*/

/* USER CODE BEGIN PV */
extern uint8_t buf;
/* USER CODE END PV */

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

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
unsigned int speedCnt = 0;

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)	//GPIO口中断(外部中断)，下降沿触发
{
	if(GPIO_Pin == GPIO_PIN_14 )		
		if(HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_14) == GPIO_PIN_RESET)		
		{
			speedCnt++;		
		}	
}
	
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)	//定时器中断服务函数，1s
{
	printf("speed:%d \r\n",speedCnt);
	speedCnt=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_USART1_UART_Init();
  MX_TIM2_Init();
  /* USER CODE BEGIN 2 */
	HAL_UART_Receive_IT(&huart1, &buf, 1);
	HAL_TIM_Base_Start_IT(&htim2);	//开启定时器中断
	
  /* USER CODE END 2 */

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

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