stm32 pwm捕获学习笔记
// Hold onto the Channel 1 init structure -- we will use it to reverse// polarity on every edge interrupt.static TIM_ICInitTypeDef TIM_CH1_ICInitStructure;#define GPIO_AF_TIM2 GPIO_AF_2void ConfigPwmIn() { GPIO_InitTypeDef GPIO_InitStructure; TIM_ICInitTypeDef TIM_ICInitStructure; NVIC_InitTypeDef NVIC_InitStructure; TIM_DeInit(TIM2 ); /* TIM2 clock enable */ RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); /* GPIOC clock enable */ RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOD, ENABLE); /* TIM2 GPIO pin configuration : CH1=PD3, C2=PD4, CH3=PD7, CH4=PD6 */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_7 | GPIO_Pin_6; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; GPIO_Init(GPIOD, &GPIO_InitStructure); /* Connect pins to TIM3 AF2 */ GPIO_PinAFConfig(GPIOD, GPIO_PinSource3, GPIO_AF_TIM2 ); GPIO_PinAFConfig(GPIOD, GPIO_PinSource4, GPIO_AF_TIM2 ); GPIO_PinAFConfig(GPIOD, GPIO_PinSource7, GPIO_AF_TIM2 ); GPIO_PinAFConfig(GPIOD, GPIO_PinSource6, GPIO_AF_TIM2 ); NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); /* Enable capture*/ TIM_CH1_ICInitStructure.TIM_Channel = TIM_Channel_1; TIM_CH1_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; TIM_CH1_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM_CH1_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; TIM_CH1_ICInitStructure.TIM_ICFilter = 0; TIM_ICInit(TIM2, &TIM_ICInitStructure); TIM_ICInitStructure.TIM_Channel = TIM_Channel_2; TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling; TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; TIM_ICInitStructure.TIM_ICFilter = 0; TIM_ICInit(TIM2, &TIM_ICInitStructure); TIM_ICInitStructure.TIM_Channel = TIM_Channel_3; TIM_ICInit(TIM2, &TIM_ICInitStructure); TIM_ICInitStructure.TIM_Channel = TIM_Channel_4; TIM_ICInit(TIM2, &TIM_ICInitStructure); /* Enable TIM2 */ TIM_Cmd(TIM2, ENABLE); /* Enable CC1-4 interrupt */ TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE); /* Clear CC1 Flag*/ TIM_ClearFlag(TIM2, TIM_FLAG_CC1 | TIM_FLAG_CC2 | TIM_FLAG_CC3 | TIM_FLAG_CC4 );}static volatile uint32_t ccr[4];static volatile char pulseState = 0;void TIM2_IRQHandler() { if (TIM2 ->SR & TIM_IT_CC1 ) { TIM2 ->SR &= (~TIM_IT_CC1 ); if (pulseState == 0) { TIM_CH1_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling; // Any time we get a rising edge on CH1, we reset the counter. All channels are // phase aligned, so they all use this as a reference. TIM_SetCounter(TIM2, 0); } else { TIM_CH1_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; // Pull the value on the falling edge. ccr[0] = TIM_GetCapture1(TIM2 ); } pulseState = !pulseState; // Reverse polarity. TIM_ICInit(TIM2, &TIM_CH1_ICInitStructure); } if (TIM2 ->SR & TIM_IT_CC2 ) { TIM2 ->SR &= (~TIM_IT_CC2 ); ccr[1] = TIM_GetCapture2(TIM2 ); } if (TIM2 ->SR & TIM_IT_CC3 ) { TIM2 ->SR &= (~TIM_IT_CC3 ); ccr[2] = TIM_GetCapture3(TIM2 ); } if (TIM2 ->SR & TIM_IT_CC4 ) { TIM2 ->SR &= (~TIM_IT_CC4 ); ccr[3] = TIM_GetCapture4(TIM2 ); }}
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