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 */
}
