STM32F407 TIM8 输入捕获功能
采用stm32f407 使用TIM8通道3初始化成输入捕获功能，捕获PB15高电平和低电平的脉宽。是使用两种方式实现：中断和DMA，有波形，但是都采集不到数据，不知道是那的问题。1.DMA方式
void TIM8_Config(void)
{
TIM_ICInitTypeDef TIM_ICInitStructure;
DMA_InitTypeDef DMA_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
TIM_Cmd(TIM8, DISABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);
/* TIM1 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8, ENABLE);
/* GPIO clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd= GPIO_PuPd_DOWN;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_TIM8);
DMA_DeInit(DMA2_Stream2);
while (DMA_GetCmdStatus(DMA2_Stream2) != DISABLE)
{
}
/* Configure DMA Stream */
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_PeripheralBaseAddr = (u32)(&TIM8->CCR3);;
DMA_InitStructure.DMA_Memory0BaseAddr = (u32)cap_buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_BufferSize = 1024;//1
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord ;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_Init(DMA2_Stream2, &DMA_InitStructure);
DMA_Cmd(DMA2_Stream2, ENABLE);
TIM_DeInit(TIM8);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_3;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_BothEdge;//TIM_ICPolarity_Falling;//TIM_ICPolarity_BothEdge;////TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0x0;
TIM_ICInit(TIM8, &TIM_ICInitStructure);
// // /* Select the TIM3 Input Trigger: TI2FP2 */
// TIM_SelectInputTrigger(TIM8, TIM_TS_TI2FP2);//TIM_TS_ETRF);
// // /* Select the slave Mode: Reset Mode */
// TIM_SelectSlaveMode(TIM8, TIM_SlaveMode_Reset);
// // /* Enable the Master/Slave Mode */
// TIM_SelectMasterSlaveMode(TIM8, TIM_MasterSlaveMode_Enable);
TIM_DMAConfig(TIM8,TIM_DMABase_CCR3,TIM_DMABurstLength_2Bytes);
/* TIM1 CC2 DMA Request enable */
TIM_DMACmd(TIM8,TIM_DMA_CC3, ENABLE);
/* TIM1 CC2 DMA Request enable */
TIM_DMACmd(TIM8,TIM_DMA_Update, ENABLE);
/* TIM enable counter */
TIM_Cmd(TIM8, ENABLE);
}
2.中断方式
void TIM8_Config(void)
{
TIM_ICInitTypeDef TIM_ICInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_DeInit(TIM8);
/* TIM1 clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM8, ENABLE);
/* GPIO clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd= GPIO_PuPd_DOWN;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
GPIO_Init(GPIOB, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_TIM8);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_3;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_BothEdge;//TIM_ICPolarity_BothEdge;//TIM_ICPolarity_Falling;//TIM_ICPolarity_BothEdge;////TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0x0;
TIM_ICInit(TIM8, &TIM_ICInitStructure);
// TIM_ITConfig(TIM8, TIM_IT_Update | TIM_IT_CC3, ENABLE);
TIM_ITConfig(TIM8,TIM_IT_CC3, ENABLE);
TIM_Cmd(TIM8, ENABLE);
// TIM_SelectInputTrigger(TIM8, TIM_TS_TI1F_ED );
NVIC_InitStructure.NVIC_IRQChannel = TIM8_BRK_TIM12_IRQn;//TIM8_BRK_TIM12_IRQn; TIM8_CC_IRQn
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
unsigned int fff=0;
void TIM8_BRK_TIM12_IRQHandler(void)
{
// if(TIM_GetITStatus(TIM8,TIM_IT_Update)==SET)
// {
// // SetTextValueInt32(2,3,sssssss++);
// TIM_ClearITPendingBit(TIM8,TIM_IT_Update);
// }
if(TIM_GetITStatus(TIM8,TIM_IT_CC3)==SET)
{
// SetTextValueInt32(2,1,sss++);
cap_buffer=TIM_GetCapture3(TIM8);//»ñÈ¡µ±Ç°µÄ²¶»ñÖµ.
fff++;
TIM_ClearITPendingBit(TIM8,TIM_IT_CC3);
}
}
两种方式都采集不到数据。
高电平和低电平时间是微秒级别的 换成这样的中断也不行，
void TIM8_CC_IRQHandler(void)
{
if(TIM_GetITStatus(TIM8,TIM_IT_CC3)==SET)
{
cap_buffer=TIM_GetCapture3(TIM8);//»ñÈ¡µ±Ç°µÄ²¶»ñÖµ.
// = TIM8->CCR3;
fff++;
}
TIM_ClearITPendingBit(TIM8,TIM_IT_CC3);
} F1系列是只有CH1和CH2才能捕获，F4系列的话你翻翻手册，是不是也是和F1一样？ 打开仿真调试，先看一下初始化完定时器和IO之后各个寄存器对不对。
然后全速运行采集过程中暂停看看 CCR3寄存器有没有值。
一般配置没问题就不会出问题。
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