STM32CubeMX配置HAL库输入捕获-编程知识

STM32CubeMX配置HAL库输入捕获

STM32的输入捕获功能可以用来测量脉冲宽度或者频率。其工作原理是，通过检测TIMx_CHx上的边沿信号，在边沿信号发生跳变（比如

上升沿/下降沿）的时候，将当前定时器的值（TIMx_CNT）存放到对应的通道的捕获/比较寄存器（TIMx_CCRx）里面，完成一次捕获。

硬件

STM32F407IGT6
Stlink
USB-TTL

软件

STM32CubeMX
CLion

配置

RCC->High Speed Clock (HSE)-> Crystal/Ceramic Resonator
SYS->Debug->Serial Wire
Clock Configuration -> HCLK->84
设置PWM->TIM3

设置输入捕获->TIM2 适当设置滤波器打开NVIC中断

默认输入捕获通道可以设置低电平，上升沿触发

编写程序

初始化变量(全局)

uint32_t capture_left_Buf[3] = {0};   //左电机存放计数值
uint32_t capture_right_Buf[3] = {0};   //右存放计数值
uint8_t capture_left_Cnt = 0;    //左电机状态标志位
uint8_t capture_right_Cnt = 0;   //右电机状态标志位
uint32_t left_time, right_time;   //周期时间
uint32_t left_speed, right_speed; //电机速度

中断服务函数

void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)// 捕获中断发生时执行
{if(htim->Instance == TIM2){if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1){switch(capture_left_Cnt){case 1:capture_left_Buf[0] = HAL_TIM_ReadCapturedValue(&htim2,TIM_CHANNEL_1);//获取当前的捕获值
//                __HAL_TIM_SET_CAPTUREPOLARITY(&htim2,TIM_CHANNEL_1,TIM_INPUTCHANNELPOLARITY_RISING);  //设置为下降沿捕获capture_left_Cnt++;break;case 2:capture_left_Buf[1] = HAL_TIM_ReadCapturedValue(&htim2,TIM_CHANNEL_1);//获取当前的捕获值.
//                capture_Num = capture_flag;
//                capture_flag = 0;HAL_TIM_IC_Stop_IT(&htim2,TIM_CHANNEL_1); //停止捕获   或者: __HAL_TIM_DISABLE(&htim2);capture_left_Cnt++;}}if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_2){switch(capture_right_Cnt){case 1:capture_right_Buf[0] = HAL_TIM_ReadCapturedValue(&htim2,TIM_CHANNEL_2);//获取当前的捕获值capture_right_Cnt++;break;case 2:capture_right_Buf[1] = HAL_TIM_ReadCapturedValue(&htim2,TIM_CHANNEL_2);//获取当前的捕获值.HAL_TIM_IC_Stop_IT(&htim2,TIM_CHANNEL_2); //停止捕获   或者: __HAL_TIM_DISABLE(&htim2);capture_right_Cnt++;}}}
}

主函数

  HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_1);HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_2);HAL_TIM_IC_Start_IT(&htim2,TIM_CHANNEL_1);  //开启TIM2的捕获通道1HAL_TIM_IC_Start_IT(&htim2,TIM_CHANNEL_2);  //开启TIM2的捕获通道2__HAL_TIM_ENABLE_IT(&htim2,TIM_IT_UPDATE);  //使能更新中断/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */while (1){/* USER CODE END WHILE *//* USER CODE BEGIN 3 */Load_PWM(500, 500);switch (capture_left_Cnt){case 0:capture_left_Cnt++;__HAL_TIM_SET_CAPTUREPOLARITY(&htim2, TIM_CHANNEL_1, TIM_INPUTCHANNELPOLARITY_RISING);HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_1);	//启动输入捕获       或者: __HAL_TIM_ENABLE(&htim2);break;case 3:left_time = capture_left_Buf[1]- capture_left_Buf[0];    //周期capture_left_Cnt = 0;  //清空标志位break;}switch (capture_right_Cnt){case 0:capture_right_Cnt++;__HAL_TIM_SET_CAPTUREPOLARITY(&htim2, TIM_CHANNEL_2, TIM_INPUTCHANNELPOLARITY_RISING);HAL_TIM_IC_Start_IT(&htim2, TIM_CHANNEL_2);	//启动输入捕获       或者: __HAL_TIM_ENABLE(&htim2);break;case 3:right_time = capture_right_Buf[1]- capture_right_Buf[0];    //周期capture_right_Cnt = 0;  //清空标志位break;}printf("{\"left_time\":%d,\"right_time\":%d} \r\n",left_time, right_time);HAL_Delay(1000);}