STM32的PWM输入模式设置并用DMA接收数据
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参考 ：STM32输入捕获模式设置并用DMA接收数据
PWM input mode
This mode is a particular case of input capture mode.
本文引用地址：https://www.eepw.com.cn/article/201611/318023.htmThe procedure is the same except:
Two ICx signals are mapped on the same TIx input.
These 2 ICx signals are active on edges with opposite polarity.
One of the two TIxFP signals is selected as trigger input and the slave mode controlleris configured in reset mode.
For example, you can measure the period (in TIMx_CCR1 register) and the duty cycle (inTIMx_CCR2 register)
of the PWM applied on TI1 using the following procedure (dependingon CK_INT frequency and prescaler value):
Select the active input for TIMx_CCR1: write the CC1S bits to 01 in the TIMx_CCMR1register (TI1 selected).
Select the active polarity for TI1FP1 (used both for capture in TIMx_CCR1 and counterclear): write the CC1P and CC1NP bits to ‘0’ (active on rising edge).
Select the active input for TIMx_CCR2: write the CC2S bits to 10 in the TIMx_CCMR1register (TI1 selected).
Select the active polarity for TI1FP2 (used for capture in TIMx_CCR2): write the CC2Pand CC2NP bits to ‘1’ (active on falling edge).
Select the valid trigger input: write the TS bits to 101 in the TIMx_SMCR register(TI1FP1 selected).
Configure the slave mode controller in reset mode: write the SMS bits to 100 in theTIMx_SMCR register.
Enable the captures: write the CC1E and CC2E bits to ‘1’ in the TIMx_CCER register.
STM32的PWM输入模式设置并用DMA接收数据
项目中需要进行红外学习,如果采用输入捕获的方式,因为定时器只能捕获上升沿或者下降沿,
所以只能获得周期,而不能得到具体的红外波的高低电平的时间.
所以采用PWM输入的方式进行捕获.采用的是PA8脚,对应TIM1的通道1.
/********************************************************************** 函数**********************************************************************//********************************************************************** 接口函数:初始化红外学习模块**********************************************************************/void inf_infrared_study_init( void ){//初始化io口inf_init_io( );//初始化中断//inf_init_irq();//初始化定时器inf_init_timer( );//打开DMAinf_infrared_study_open_dma( 1 );//打开定时器inf_infrared_study_open_timer( 1 );}/********************************************************************** 初始化io口**********************************************************************/static void inf_init_io( void ){//定义IO初始化结构体GPIO_InitTypeDef GPIO_InitStructure;//初始化时钟RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE );//管脚初始化 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;//设置为输入 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//初始化 GPIO_Init( GPIOA, &GPIO_InitStructure );}/********************************************************************** 初始化中断**********************************************************************/static void inf_init_irq( void ){//定义外部中断结构体EXTI_InitTypeDef EXTI_InitStructure;//初始化中断脚复用时钟RCC_APB2PeriphClockCmd( RCC_APB2Periph_AFIO, ENABLE );//配置中断源GPIO_EXTILineConfig( GPIO_PortSourceGPIOB, GPIO_PinSource1 );// 配置下降沿触发EXTI_ClearITPendingBit( EXTI_Line1 );EXTI_InitStructure.EXTI_Line = EXTI_Line1;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_Init( &EXTI_InitStructure );}/********************************************************************** 初始化定时器**********************************************************************/static void inf_init_timer( void ){//定义定时器结构体TIM_TimeBaseInitTypeDef timInitStruct;//输入捕获结构体TIM_ICInitTypeDef tim_icinit;//定义DMA结构体DMA_InitTypeDef DMA_InitStructure;//启动DMA时钟RCC_AHBPeriphClockCmd( RCC_AHBPeriph_DMA1, ENABLE );//DMA1通道配置DMA_DeInit( DMA1_Channel2 );//外设地址DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) ( &TIM1->CCR1 );//内存地址DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) Rx_Buf_Tim_Dma1;//dma传输方向单向DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;//设置DMA在传输时缓冲区的长度DMA_InitStructure.DMA_BufferSize = RX_LEN_TIM_DMA;//设置DMA的外设递增模式，一个外设DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//设置DMA的内存递增模式DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//外设数据字长DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;//内存数据字长DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;//设置DMA的传输模式//DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//设置DMA的优先级别DMA_InitStructure.DMA_Priority = DMA_Priority_High;//设置DMA的2个memory中的变量互相访问DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;DMA_Init( DMA1_Channel2, &DMA_InitStructure );//启动DMA时钟RCC_AHBPeriphClockCmd( RCC_AHBPeriph_DMA1, ENABLE );//DMA1通道配置DMA_DeInit( DMA1_Channel3 );//外设地址DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) ( &TIM1->CCR2 );//内存地址DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t) Rx_Buf_Tim_Dma2;//dma传输方向单向DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;//设置DMA在传输时缓冲区的长度DMA_InitStructure.DMA_BufferSize = RX_LEN_TIM_DMA;//设置DMA的外设递增模式，一个外设DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//设置DMA的内存递增模式DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//外设数据字长DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;//内存数据字长DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;//设置DMA的传输模式//DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//设置DMA的优先级别DMA_InitStructure.DMA_Priority = DMA_Priority_High;//设置DMA的2个memory中的变量互相访问DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;DMA_Init( DMA1_Channel3, &DMA_InitStructure );//开启时钟RCC_APB2PeriphClockCmd( RCC_APB2Periph_TIM1, ENABLE );//重新将Timer设置为缺省值TIM_DeInit( TIM1 );//采用内部时钟提供时钟源TIM_InternalClockConfig( TIM1 );//预分频timInitStruct.TIM_ClockDivision = TIM_CKD_DIV1;//计数频率为500ns跳转1次 timInitStruct.TIM_Prescaler = SystemCoreClock / 1 - 1;//向上计数 timInitStruct.TIM_CounterMode = TIM_CounterMode_Up;timInitStruct.TIM_RepetitionCounter = 0;//这个值实际上就是TIMX->ARR，延时开始时重新设定即可 timInitStruct.TIM_Period = 0xffff;//初始化定时器TIM_TimeBaseInit( TIM1, &timInitStruct );//输入捕获配置//选择通道tim_icinit.TIM_Channel = TIM_Channel_1;//硬件滤波tim_icinit.TIM_ICFilter = 0x0;//触发捕获的电平tim_icinit.TIM_ICPolarity = TIM_ICPolarity_Falling;//每次检测到触发电平都捕获tim_icinit.TIM_ICPrescaler = TIM_ICPSC_DIV1;//通道方向选择tim_icinit.TIM_ICSelection = TIM_ICSelection_DirectTI;//初始化//TIM_ICInit(TIM1,&tim_icinit);TIM_PWMIConfig( TIM1, &tim_icinit );//禁止ARR预装载缓冲器 //TIM_ARRPreloadConfig(TIM1, DISABLE); //输入跳变选择TIM_SelectInputTrigger( TIM1, TIM_TS_TI1FP1 );//从机模式:复位模式TIM_SelectSlaveMode( TIM1, TIM_SlaveMode_Reset );//主从模式选择TIM_SelectMasterSlaveMode( TIM1, TIM_MasterSlaveMode_Enable );//配置定时器的DMATIM_DMAConfig( TIM1, TIM_DMABase_CCR1, TIM_DMABurstLength_2Bytes );//产生DMA请求信号TIM_DMACmd( TIM1, TIM_DMA_CC1, ENABLE );//配置定时器的DMATIM_DMAConfig( TIM1, TIM_DMABase_CCR2, TIM_DMABurstLength_2Bytes );//产生DMA请求信号TIM_DMACmd( TIM1, TIM_DMA_CC2, ENABLE );//打开定时器TIM_Cmd( TIM1, ENABLE );}/********************************************************************** 接口函数:打开定时器*参数:state:状态:0:关闭,1:打开**********************************************************************/void inf_infrared_study_open_timer( uint8_t state ){if ( state ){TIM_Cmd( TIM1, ENABLE );}else{TIM_Cmd( TIM1, DISABLE );}}/********************************************************************** 接口函数:打开中断*参数:state:状态:0:关闭,1:打开**********************************************************************/void inf_infrared_study_open_irq( uint8_t state ){//定义中断结构体NVIC_InitTypeDef NVIC_InitStructure;if ( state ){//打开中断NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn; //通道设置为外部中断线NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //中断抢占先等级NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //中断响应优先级NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //打开中断NVIC_Init( &NVIC_InitStructure ); //初始化}else{//关闭中断NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn; //通道设置为外部中断线NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; //中断抢占先等级NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //中断响应优先级NVIC_InitStructure.NVIC_IRQChannelCmd = DISABLE; //打开中断NVIC_Init( &NVIC_InitStructure ); //初始化}}/********************************************************************** 接口函数:打开DMA*参数:state:状态:0:关闭,1:打开**********************************************************************/void inf_infrared_study_open_dma( uint8_t state ){if ( state ){//设置传输数据长度//DMA_SetCurrDataCounter(DMA1_Channel3,RX_LEN_TIM_DMA);//打开DMADMA_Cmd( DMA1_Channel2, ENABLE );DMA_Cmd( DMA1_Channel3, ENABLE );}else{DMA_Cmd( DMA1_Channel2, DISABLE );DMA_Cmd( DMA1_Channel3, ENABLE );}}/********************************************************************** 接口函数:得到DMA接收帧长*返回:帧长**********************************************************************/uint16_t inf_infrared_study_dma_rx_len( void ){//获得接收帧帧长return ( RX_LEN_TIM_DMA - DMA_GetCurrDataCounter( DMA1_Channel2 ) );}
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