第十一届蓝桥杯嵌入式组别底层驱动程序11(PWM④)
捕获两路PWM的频率和占空比
比如通过输入捕获得到PA6和PA7的频率和占空比:
void capture_Init()
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_ICInitTypeDef TIM_ICInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7|GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);;
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 71;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0x0;
TIM_ICInit(TIM3, &TIM_ICInitStructure);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
TIM_ICInit(TIM3, &TIM_ICInitStructure);
TIM_Cmd(TIM3, ENABLE);
TIM_ITConfig(TIM3, TIM_IT_Update|TIM_IT_CC2|TIM_IT_CC1, ENABLE);
}
__IO uint16_t IC3ReadValue12 = 0, IC3ReadValue22 = 0;
__IO uint16_t CaptureNumber2 = 0;
__IO uint32_t Capture2 = 0;
__IO uint32_t TIM3Freq2 = 0;
u8 eage2=0;
u16 rising2=0,falling2=0;
float zhankong2=0;
__IO uint16_t IC3ReadValue11 = 0, IC3ReadValue21 = 0;
__IO uint16_t CaptureNumber1 = 0;
__IO uint32_t Capture1 = 0;
__IO uint32_t TIM3Freq1 = 0;
u8 eage1=0;
u16 rising1=0,falling1=0;
float zhankong1=0;
void TIM3_IRQHandler(void)
{
if(TIM_GetITStatus(TIM3, TIM_IT_CC2) == SET)
{
if(eage2==0)
{
if(CaptureNumber2 == 0)
{
IC3ReadValue12 = TIM_GetCapture2(TIM3);
CaptureNumber2 = 1;
}
else if(CaptureNumber2 == 1)
{
IC3ReadValue22 = TIM_GetCapture2(TIM3);
if (IC3ReadValue22 > IC3ReadValue12)
{
Capture2= (IC3ReadValue22 - IC3ReadValue12);
}
else
{
Capture2 = ((0xFFFF - IC3ReadValue12) + IC3ReadValue22);
}
TIM3Freq2 = (uint32_t) SystemCoreClock /72/ Capture2;
CaptureNumber2 = 0;
}
rising2=TIM_GetCapture2(TIM3);
TIM_OC2PolarityConfig(TIM3, TIM_ICPolarity_Falling);
eage2=1;
}
else if(eage2==1)
{
falling2=TIM_GetCapture2(TIM3);
if(falling2>rising2)
{
zhankong2=(float)(falling2-rising2)/Capture2;
}
else if(falling2<rising2)
{
zhankong2=(float)(0xFFFF-falling2+rising2)/Capture2;
}
eage2=0;
TIM_OC2PolarityConfig(TIM3, TIM_ICPolarity_Rising);
}
TIM_ClearITPendingBit(TIM3, TIM_IT_Update|TIM_IT_CC2);
}
if(TIM_GetITStatus(TIM3, TIM_IT_CC1) == SET)
{
if(eage1==0)
{
if(CaptureNumber1 == 0)
{
IC3ReadValue11 = TIM_GetCapture1(TIM3);
CaptureNumber1 = 1;
}
else if(CaptureNumber1 == 1)
{
IC3ReadValue21 = TIM_GetCapture1(TIM3);
if (IC3ReadValue21 > IC3ReadValue11)
{
Capture1= (IC3ReadValue21 - IC3ReadValue11);
}
else
{
Capture1 = ((0xFFFF - IC3ReadValue11) + IC3ReadValue21);
}
TIM3Freq1 = (uint32_t) SystemCoreClock /72/ Capture1;
CaptureNumber1 = 0;
}
rising1=TIM_GetCapture1(TIM3);
TIM_OC1PolarityConfig(TIM3, TIM_ICPolarity_Falling);
eage1=1;
}
else if(eage1==1)
{
falling1=TIM_GetCapture1(TIM3);
if(falling1>rising1)
{
zhankong1=(float)(falling1-rising1)/Capture1;
}
else if(falling1<rising1)
{
zhankong1=(float)(0xFFFF-falling1+rising1)/Capture1;
}
eage1=0;
TIM_OC1PolarityConfig(TIM3, TIM_ICPolarity_Rising);
}
TIM_ClearITPendingBit(TIM3, TIM_IT_Update|TIM_IT_CC1);
}
}
频率就是TIM3Freq1和TIM3Freq2
占空比就是zhankong1和zhankong2V3.5库的"Project->STM32F10x_StdPeriph_Examples->TIM-InputCapture"文件夹下,"main.c"和"stm32f10x_it.c"分别有着输入捕获模式初始化和中断服务程序相关代码:
原文链接:https://blog.csdn.net/Zach_z/article/details/80548423