Air001 高级定时器输入捕获功能测量脉宽和频率

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• ✨Air001只有1个16位高级定时器，经实际测试发现，通道1用于输入捕获功能失效，不确定是否是IO引脚存在问题还是硬件bug，折腾了好久，最后切换到通道2使用，就可以捕获到了，其余通道3和通道4没有做有效性测试。

• 🌿对于ARM 32位的M0+内核单片机,同STM32同内核架构的单片机，在定时器的使用上都一样，代码基本可以照搬。
• 🔰本文主要是将STM32代码移植到该芯片工程中，验证功能。
• 🌿测试了采用高级定时器通道1和通道2，复位模式，测量脉宽信号，发现也是不行的，在STM32f030上使用都正常的。《STM32 HAL库定时器输入捕获SlaveMode脉宽测量》
  

• 🔖Air001价格比较便宜，硬件上还是有很多暗坑或设计缺陷的，在选择移植切换方案时，最好提前做好功能验证。

• 📑定时器输入捕获配置函数：

void MX_TIM1_Init(void)
{/* USER CODE BEGIN TIM1_Init 0 *//* USER CODE END TIM1_Init 0 */TIM_ClockConfigTypeDef sClockSourceConfig = {0};TIM_MasterConfigTypeDef sMasterConfig = {0};TIM_IC_InitTypeDef sConfigIC = {0};/* USER CODE BEGIN TIM1_Init 1 *//* USER CODE END TIM1_Init 1 */htim1.Instance = TIM1;htim1.Init.Prescaler = 23;//1MHzhtim1.Init.CounterMode = TIM_COUNTERMODE_UP;htim1.Init.Period = 65535;htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;htim1.Init.RepetitionCounter = 0;htim1.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;if (HAL_TIM_Base_Init(&htim1) != HAL_OK){Error_Handler();}sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK){Error_Handler();}if (HAL_TIM_IC_Init(&htim1) != HAL_OK){Error_Handler();}sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK){Error_Handler();}sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;sConfigIC.ICFilter = 0;if (HAL_TIM_IC_ConfigChannel(&htim1, &sConfigIC, TIM_CHANNEL_2) != HAL_OK)//通道2{Error_Handler();}/* TIM1使能启动，并使能中断 */if (HAL_TIM_Base_Start_IT(&htim1) != HAL_OK){Error_Handler();}
}

• 🔧定时器输入捕获引脚配置以及中断优先级配置

void HAL_TIM_Base_MspInit(TIM_HandleTypeDef* tim_baseHandle)
{GPIO_InitTypeDef GPIO_InitStruct = {0};if(tim_baseHandle->Instance==TIM1){/* USER CODE BEGIN TIM1_MspInit 0 *//* USER CODE END TIM1_MspInit 0 *//* TIM1 clock enable */__HAL_RCC_TIM1_CLK_ENABLE();
//		__HAL_RCC_GPIOA_CLK_ENABLE();__HAL_RCC_GPIOB_CLK_ENABLE();/**TIM1 GPIO ConfigurationPA3   GPIO_AF13_TIM1  ------> TIM1_CH1PB3  GPIO_AF1_TIM1  ------> TIM1_CH2*/GPIO_InitStruct.Pin = GPIO_PIN_3;GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;GPIO_InitStruct.Pull = GPIO_NOPULL;GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;GPIO_InitStruct.Alternate = GPIO_AF1_TIM1;HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);/* TIM1 interrupt Init */HAL_NVIC_SetPriority(TIM1_BRK_UP_TRG_COM_IRQn, 2, 0);HAL_NVIC_EnableIRQ(TIM1_BRK_UP_TRG_COM_IRQn);HAL_NVIC_SetPriority(TIM1_CC_IRQn, 1, 0);//输入捕获优先级>更新溢出中断HAL_NVIC_EnableIRQ(TIM1_CC_IRQn);/* USER CODE BEGIN TIM1_MspInit 1 *//* USER CODE END TIM1_MspInit 1 */}if(tim_baseHandle->Instance==TIM16)//用于产生PWM信号{/* USER CODE BEGIN TIM16_MspInit 0 *//* USER CODE END TIM16_MspInit 0 *//* TIM16 clock enable */__HAL_RCC_TIM16_CLK_ENABLE();/* USER CODE BEGIN TIM16_MspInit 1 *//* USER CODE END TIM16_MspInit 1 */}
}

• 🌿系统时钟频率配置（本例程测试用于内部时钟，频率24MHz）

/*** @brief   配置系统时钟* @param   HSICLKSource_SET：选择HSI时钟频率*            @arg @ref RCC_HSICALIBRATION_8MHz：8M时钟*            @arg @ref RCC_HSICALIBRATION_16MHz：16M时钟*            @arg @ref RCC_HSICALIBRATION_22p12MHz：22.12M时钟*            @arg @ref RCC_HSICALIBRATION_24MHz：24M时钟* @retval  无*/
void SystemClock_Config(uint32_t HSICLKSource_SET)
{RCC_OscInitTypeDef RCC_OscInitStruct = {0};RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};//  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
//  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;/* 配置HSI时钟 */RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;RCC_OscInitStruct.HSIState = RCC_HSI_ON;                                      /* 使能HSI */RCC_OscInitStruct.HSIDiv =    RCC_HSI_DIV1;                                   /* HSI预分频 */RCC_OscInitStruct.HSICalibrationValue = HSICLKSource_SET;/* 设置HSI输出时钟库会设置校准值 */if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)                           /* 配置时钟 */{Error_Handler();}/* 初始化AHB,APB总线时钟 */RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_PCLK1;RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;                         /* 配置AHB时钟源 */RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;                             /* 设置AHB预分频 */RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;                              /* 设置APB1预分频 */if(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)         /* 配置总线 */{Error_Handler();}
}

• 🌿定时器中断回调函数

/*** @brief 输入捕获回调函数* @retval None*/
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef* htim)
{static uint8_t RisingEdge_count = 0;if(htim->Channel == HAL_TIM_ACTIVE_CHANNEL_2){__HAL_TIM_CLEAR_IT(&htim1, TIM_IT_CC2);//清零中断标志位if(capture_flag & 0x40)										//0X40是0100 0000，高电平期间捕获到下降沿{capture_flag &= 0x3F;										//0X3F是0011 1111，清除捕获到上升沿的标记位和捕获完成的标记位value2 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2);	//获取当前的捕获值__HAL_TIM_DISABLE(htim);        						//关闭定时器__HAL_TIM_SET_COUNTER(htim, value2);						//以value2为基准重新计数TIM_RESET_CAPTUREPOLARITY(htim, TIM_CHANNEL_2);      	//复位极性选择才能进行下行配置/*输入捕获功能的重配与开启，硬件启动会产生几个时钟的延迟*/TIM_SET_CAPTUREPOLARITY(htim, TIM_CHANNEL_2, TIM_ICPOLARITY_RISING);	//下次上升沿捕获__HAL_TIM_ENABLE(htim);									//重开定时器}else	            								 		//捕获到上升沿{capture_flag |= 0x40;										//0X40是0100 0000，标记捕捉到了一次上升沿RisingEdge_count++;if((RisingEdge_count % 2 == 0))								//每捕获两次相同跳变沿表示过了一个PWM周期{value3 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2); //检测完一个周期的那个上升沿为value3capture_flag |= 0x80;								 //标记捕获完了一个周期Pulse_Width = (value2 + OverflowCount_high * TIM1_Period_Value - value1 + 7)/2;	//7 时钟补偿PWM_Period_ARR[PWM_Period_CNT++] = value3 + OverflowCount_high * TIM1_Period_Value + OverflowCount_low * TIM1_Period_Value - value1 - 3;if(PWM_Period_CNT == 5)//5次读取，取出现频率最高的值{PWM_Period = findMostFrequentNum(PWM_Period_ARR, 5)/2;//2MHZ计数PWM_Period_CNT = 0;}OverflowCount_high = OverflowCount_low = 0;//清空溢出计数}else				 								   //正在检测PWM信号的第一个上升沿，意味着下次捕获下降沿{capture_flag &= 0x7F;								 //0X7F是0111 1111，清除PWM捕获完成标志，开始新一轮PWM周期捕获value1 = HAL_TIM_ReadCapturedValue(htim, TIM_CHANNEL_2); //第一个上升沿是value1}__HAL_TIM_DISABLE(htim);__HAL_TIM_SET_COUNTER(htim, value1);					//以value1为基准重新计数TIM_RESET_CAPTUREPOLARITY(htim, TIM_CHANNEL_2);  	//复位极性选择才能进行下行配置TIM_SET_CAPTUREPOLARITY(htim, TIM_CHANNEL_2, TIM_ICPOLARITY_FALLING);	//下次下降沿捕获__HAL_TIM_ENABLE(htim);								//重开定时器}}
}/*** @brief 更新溢出回调函数* @retval None*/
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef* htim)
{__HAL_TIM_CLEAR_IT(&htim1, TIM_IT_UPDATE);//清零中断标志位if((capture_flag & 0X80) == 0)			//PWM的一个周期没检测完{if(capture_flag & 0x40)				//在高电平期间溢出M次{OverflowCount_high++;}else								//在低电平期间溢出N次{OverflowCount_low++;}}else								   //PWM的一个周期检测完了{OverflowCount_high = 0;OverflowCount_low = 0;}
}

• 📝main函数

volatile uint32_t  ARR_Value, PWM_f;
volatile char capture_flag = 0;				//捕获状态标记变量,0x80最高位标记捕获完一个周期，0x40表示捕获到了上升沿
volatile uint8_t OverflowCount_high = 0;		//高电平期间溢出次数
volatile uint8_t OverflowCount_low = 0;		//低电平期间溢出次数
volatile uint32_t value1, value2, value3;	  //三个边沿中的值
volatile uint32_t Pulse_Width = 0;		  //脉宽
volatile uint32_t PWM_Period = 0;				//周期
uint32_t PWM_Period_ARR[5] = {0};
uint8_t PWM_Period_CNT = 0;
int main(void)
{uint32_t TimerUART;uint8_t USART_TX_Buff[40] = {0};/* 初始化所有外设，Flash接口，SysTick */HAL_Init();SystemClock_Config(RCC_HSICALIBRATION_24MHz);APP_GpioConfig();HAL_TIM_Base_MspInit(&htim1);MX_TIM1_Init();MX_TIM16_Init();MX_USARTx_UART_Init();
//    __HAL_TIM_SET_AUTORELOAD(&htim16, plusewidth - 1); //调整分频系数，TIM16->ARR
//    __HAL_TIM_SET_COMPARE(&htim16, TIM_CHANNEL_2, plusedelay); //PWM脉冲宽度,TIM16->CCR1修改占空比比较值HAL_TIM_PWM_Start(&htim16, TIM_CHANNEL_1); //开启PWM输出通道:PA6HAL_TIM_Base_Start_IT(&htim1);
//		__HAL_TIM_ENABLE_IT(&htim1, TIM_IT_UPDATE); //启动更新中断__HAL_TIM_URS_ENABLE(&htim1);               //更新中断只有溢出时触发/* 清零中断标志位 */__HAL_TIM_CLEAR_IT(&htim1, TIM_IT_UPDATE);/* 使能定时器的更新事件中断 */__HAL_TIM_ENABLE_IT(&htim1, TIM_IT_UPDATE);//使能更新中断/* 使能输入捕获 */HAL_TIM_IC_Start_IT(&htim1, TIM_CHANNEL_2);TimerUART = HAL_GetTick();printf("Air001 SysClockFreq:%d \r\n", HAL_RCC_GetSysClockFreq());while(1){
//        HAL_Delay(1000);if((HAL_GetTick() - TimerUART) > 1000){/* LED翻转 */HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_0);HAL_GPIO_TogglePin(GPIOB, GPIO_PIN_1);PWM_f = 1000000l / PWM_Period;sprintf((char*)USART_TX_Buff, "Pulse_Width:%dus,PWM_Period:%d,PWM_f:%dHz", Pulse_Width, PWM_Period, PWM_f);printf("%s \n", USART_TX_Buff);memset((char*)USART_TX_Buff, '\0', strlen((char*)USART_TX_Buff)); //清空数组TimerUART = HAL_GetTick();}}
}

• 🌿当被测量信号频率越高时，误差就越大。
  

• 🌿被测信号频率比较低时，测量结果：
  

📚测试工程

链接：https://pan.baidu.com/s/1OIf_XiWwRuBVPgidumX_SQ 
提取码：93ev