我的程序如下，
个人思路是TIM1的CH3输出PWM波形，
然后使用TIM3的CH2捕获PWM波形
系统时钟96MHz
//TIM1 PWM部分初始化
//PWM输出初始化
//arr：自动重装值
//psc：时钟预分频数
void TIM1_PWM_Init(u32 arr,u32 psc)
{
//此部分需手动修改IO口设置
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE); //TIM1时钟使能
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTA时钟
GPIO_PinAFConfig(GPIOA,GPIO_PinSource11,GPIO_AF_TIM1); //GPIOF11复用为定时器1
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11; //GPIOA11
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //复用功能
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //推挽复用输出
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; //上拉
GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA11
TIM_TimeBaseStructure.TIM_Prescaler=psc; //定时器分频
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
TIM_TimeBaseStructure.TIM_Period=arr; //自动重装载值
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM1,&TIM_TimeBaseStructure);//初始化定时器14
//初始化TIM1 Channel4 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性:TIM输出比较极性低
// TIM_OCInitStructure.TIM_Pulse =1000;
//根据使用的函数 选择不同的通道
TIM_OC4Init(TIM1, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM1OC1
TIM_OC4PreloadConfig(TIM1, TIM_OCPreload_Enable); //使能TIM14在CCR1上的预装载寄存器
TIM_ARRPreloadConfig(TIM1,ENABLE);//ARPE使能
TIM_Cmd(TIM1, ENABLE); //使能TIM1
TIM_CtrlPWMOutputs(TIM1, ENABLE);//使能TIM1的PWM输出，TIM1与TIM8有效
}
//定时器3通道2输入捕获配置
//arr：自动重装值(TIM2,TIM5是32位的!!) (TIM3 和 TIM4 16位
//psc：时钟预分频数
void TIM3_CH2_Cap_Init()
{
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_ICInitTypeDef TIM_ICInitStructure;
/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/* GPIOB clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
/* TIM3 chennel2 configuration : PC.07 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
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_UP ;
GPIO_Init(GPIOC, &GPIO_InitStructure);
/* Connect TIM pin to AF2 */
GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_TIM3);
/* Enable the TIM3 global Interrupt */
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_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_PWMIConfig(TIM3, &TIM_ICInitStructure);
/* Select the TIM3 Input Trigger: TI2FP2 */
TIM_SelectInputTrigger(TIM3, TIM_TS_TI2FP2);
/* Select the slave Mode: Reset Mode */
TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);
TIM_SelectMasterSlaveMode(TIM3,TIM_MasterSlaveMode_Enable);
/* TIM enable counter */
TIM_Cmd(TIM3, ENABLE);
/* Enable the CC2 Interrupt Request */
TIM_ITConfig(TIM3, TIM_IT_CC2, ENABLE);
}
/**
* @brief This function handles TIM4 global interrupt request.
* @param None
* @retval None
*/
void TIM3_IRQHandler(void)
{
RCC_ClocksTypeDef RCC_Clocks;
RCC_GetClocksFreq(&RCC_Clocks);
if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)//捕获1发生捕获事件
{
/* Clear TIM3 Capture compare interrupt pending bit */
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
/* Get the Input Capture value */
PWMCCP.Period= TIM_GetCapture2(TIM3); //周期
if (PWMCCP.Period != 0)
{
PWMCCP.PulseWidth =TIM_GetCapture1(TIM3); //脉冲宽度
/* Duty cycle computation */
PWMCCP.DutyCycle = (TIM_GetCapture1(TIM3) * 100) / PWMCCP.Period; //占空比
/* Frequency computation
TIM3 counter clock = (RCC_Clocks.HCLK_Frequency)/2 */
PWMCCP.Frequency = (RCC_Clocks.HCLK_Frequency)/2 / PWMCCP.Period;
}
else
{
PWMCCP.DutyCycle = 0;
PWMCCP.Frequency = 0;
}
}
}
在主函数里我的PWM的占空是50%，使用示波器看了，PWM波形没问题
但是捕获得到的数据不正常 占空比和周期都不正确 |
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