STM32的PWM输入模式设置并用DMA接收数据

本文博客链接:,作者:jdh,转载请注明.

环境：

主机:WIN7

开发环境:MDK4.72

MCU:

说明：

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.

源代码:

/**********************************************************************       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DMA    inf_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); // 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 / 1000000 - 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   //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DMA    TIM_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DMA    TIM_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DMA  DMA_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));}