STM32的PWM输入模式设置并用DMA接收数据

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.

The 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 ) );}