定时器TIM3 ch1 完全映射到PC6上面，做输入捕获

猪尾卡卡 · 发表于 2015-8-13 17:00:14

本实验是为了用TIM3映射到PC6上面，做输入捕获，即检测低电平的输入时间。
如果TIM3不映射的话，用PA6是没问题的。
但是映射这个实验，加了几条初始化语句，用串口看到的是一直打印出来65536。
请大神看看哪里出问题了？实在搞不清楚，看手册也觉得没错。

[mw_shl_code=c,true]#include "timer.h" #include "led.h" #include "usart.h" TIM_ICInitTypeDef TIM3_ICInitStructure; void TIM3_Cap_Init(u16 arr,u16 psc) { GPIO_InitTypeDef GPIO_InitStructure; TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; NVIC_InitTypeDef NVIC_InitStructure; RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); GPIO_AFIODeInit(); GPIO_PinRemapConfig(GPIO_FullRemap_TIM3,ENABLE); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; GPIO_Init(GPIOC, &GPIO_InitStructure); TIM_DeInit(TIM3); TIM_TimeBaseStructure.TIM_Period = arr; TIM_TimeBaseStructure.TIM_Prescaler =psc; TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); TIM3_ICInitStructure.TIM_Channel = TIM_Channel_1; TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling; TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; TIM3_ICInitStructure.TIM_ICFilter = 0x03; TIM_ICInit(TIM3, &TIM3_ICInitStructure); NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; TIM_ITConfig(TIM3,TIM_IT_Update|TIM_IT_CC1,ENABLE); TIM_Cmd(TIM3,ENABLE ); } u8 TIM3CH1_CAPTURE_STA=0; u16 TIM3CH1_CAPTURE_VAL; void TIM3_IRQHandler(void) { if((TIM3CH1_CAPTURE_STA&0X80)==0) { if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) { if(TIM3CH1_CAPTURE_STA&0X40) { if((TIM3CH1_CAPTURE_STA&0X3F)==0X3F) { TIM3CH1_CAPTURE_STA|=0X80; TIM3CH1_CAPTURE_VAL=0XFFFF; }else TIM3CH1_CAPTURE_STA++; } } if (TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET) { if(TIM3CH1_CAPTURE_STA&0X40) { TIM3CH1_CAPTURE_STA|=0X80; TIM3CH1_CAPTURE_VAL=TIM_GetCapture1(TIM3); TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Falling); }else { TIM3CH1_CAPTURE_STA=0; TIM3CH1_CAPTURE_VAL=0; TIM_SetCounter(TIM3,0); TIM3CH1_CAPTURE_STA|=0X40; TIM_OC1PolarityConfig(TIM3,TIM_ICPolarity_Rising); } } } TIM_ClearITPendingBit(TIM3, TIM_IT_CC1|TIM_IT_Update); } [/mw_shl_code]

猪尾卡卡 · 发表于 2015-8-13 17:00:15

原子哥的思路提醒了我，换了下初始化的顺序，还真的就可以了！

正确的顺序如下，管脚映射之前先使能IO口时钟，定时器时钟和复用时钟。

大爱原子哥哈哈

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);

GPIO_AFIODeInit();
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3,ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; //PC6 ?壺眳?扢离
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //奻嶺怀?
GPIO_Init(GPIOC, &GPIO_InitStructure);

TIM_DeInit(TIM3);