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本帖最后由 lwj199302 于 2016-7-25 15:48 编辑
输入捕获通道是PA7->TIM3_CH2
#include "stm32f0xx.h"
#include "water_control.h"
u16 TIM3_CH2_STA=0; //输入捕获状态
u16 TIM3_CH2_VAL; //输入捕获值
void TIM3_CH2_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_ICInitTypeDef TIM3_ICInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStructure.GPIO_PuPd=GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_ResetBits(GPIOA,GPIO_Pin_7);
TIM_TimeBaseStructure.TIM_Period = 0xffff;
TIM_TimeBaseStructure.TIM_Prescaler =47;
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_2; //CC1S=01 选择输入端 IC1映射到TI1上
TIM3_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Falling; //下降沿捕获
TIM3_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM3_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM3_ICInitStructure.TIM_ICFilter = 0x00;
TIM_ICInit(TIM3, &TIM3_ICInitStructure);
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPriority=0x02;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
TIM_ITConfig(TIM3,TIM_IT_Update|TIM_IT_CC2,ENABLE);
TIM_Cmd(TIM3,ENABLE );
}
void TIM3_IRQHandler(void)
{
if((TIM3_CH2_STA&0X8000)==0)//还未成功捕获
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
{
if(TIM3_CH2_STA&0X4000)//已经捕获到低电平了
{
if((TIM3_CH2_STA&0X3FFF)==0X3FFF)//低电平太长了
{
TIM3_CH2_STA|=0X8000;//标记成功捕获了一次
TIM3_CH2_VAL=0XFFFF;
}
else
TIM3_CH2_STA++;
}
}
if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)//发生捕获事件
{
if(TIM3_CH2_STA&0X4000) //捕获到一个上升沿
{
TIM3_CH2_STA|=0X8000; //标记成功捕获到一次上升沿
TIM3_CH2_VAL=TIM_GetCapture2(TIM3);
TIM_OC2PolarityConfig(TIM3,TIM_ICPolarity_Falling); //CC1P=0 设置为下降沿捕获
}
else //还未开始,第一次捕获下降沿
{
TIM3_CH2_STA=0; //清空
TIM3_CH2_VAL=0;
TIM_SetCounter(TIM3,0);
TIM3_CH2_STA|=0X4000; //标记捕获到了下降沿
TIM_OC2PolarityConfig(TIM3,TIM_ICPolarity_Rising); //设置为上升沿捕获
}
}
}
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2|TIM_IT_Update);
}
#include "stm32f0xx.h"
#include "init.h"
#include "water_control.h"
extern u16 TIM3_CH2_STA; //输入捕获状态
extern u16 TIM3_CH2_VAL; //输入捕获值
int main(void)
{
u32 temp=0;
SystemInit(); //系统时钟初始化
system_device_init(); //系统硬件初始化
system_parameter_init(); //系统运行参数初始化
while(1)
{
if(TIM3_CH2_STA&0X8000)//捕获到一次低电平
{
temp=TIM3_CH2_STA&0X3FFF;
temp*=65536;
temp+=TIM3_CH2_VAL;
TIM3_CH2_STA=0;
}
}
}
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最佳答案
查看完整内容[请看2#楼]
已解决
配置错误了
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7; //TIM3是复用功能
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType=GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd=GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_SetBits(GPIOA,GPIO_Pin_7);
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