今天弄了大半天，想用PWM输入比较模式测频率，我是根据库3.5的例子编写的，但是调试的时候发现程序一直没能进入中断，导致频率一直没出，程序如下，还望解答~~感激不尽
void RCC_CFG(void)
{
//APB2 GPIOA,AFIO,
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|
RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOD,ENABLE);
//APB1 TIM3
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);
}
void GPIO_CFG(void)
{
//输入捕获的测试中所用端口为TIM3-CHANNEL2--PA.7,浮空输入
GPIO_InitTypeDef GPIO_InitStructrue;
GPIO_InitStructrue.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructrue.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_InitStructrue.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructrue);
}
void NVIC_CFG(void)//设置串口，用来发送测得的频率
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); //设置为组2
//SET AND ENABLE THE WWDG INTERRUPT
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //设置中断通道13
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //抢占优先级为0
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //响应优先级为0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能该通道中断
NVIC_Init(&NVIC_InitStructure);
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn; //设置中断通道13
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //抢占优先级为0
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2; //响应优先级为0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能该通道中断
NVIC_Init(&NVIC_InitStructure);
}
void USART1_CFG(void)
{
USART_InitTypeDef USART_InitStructure;
USART_InitStructure. USART_BaudRate = 9600; //波特率设置为9600
USART_InitStructure. USART_WordLength = USART_WordLength_8b; //数据位
USART_InitStructure.USART_StopBits = USART_StopBits_1; //停止位
USART_InitStructure.USART_Parity = USART_Parity_No; //校验位
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None; //流量控制
USART_InitStructure.USART_Mode = USART_Mode_Rx|USART_Mode_Tx; //串口模式
USART_Init(USART1,&USART_InitStructure);
USART_Cmd(USART1,ENABLE);
//开串口中断
USART_ITConfig(USART1,USART_IT_RXNE,ENABLE); //使能中断允许接收 //初始化
}
void TIM_Input_Capture_CFG(void)
{
TIM_ICInitTypeDef TIM_ICInitStructure;
TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;//TIM的输入端2.3.4与ICx的对应关系
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;//捕获预分频，此处设置为捕获一次事件就执行
TIM_ICInitStructure.TIM_ICFilter = 0x0; //滤波器
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);
/* Enable the Master/Slave Mode */
TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable);
TIM_Cmd(TIM3,ENABLE);
TIM_ITConfig(TIM3,TIM_IT_CC2,ENABLE);
}
然后是中断的程序
void TIM3_IRQHandler(void)
{
/* Clear TIM3 Capture compare interrupt pending bit */
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
/* Get the Input Capture value */
IC2Value = TIM_GetCapture2(TIM3);
if (IC2Value != 0)
{
/* Duty cycle computation */
DutyCycle = (TIM_GetCapture1(TIM3) * 100) / IC2Value;
/* Frequency computation */
Frequency = SystemCoreClock / IC2Value;
}
else
{
DutyCycle = 0;
Frequency = 0;
}
}
然后是主函数
int main(void)
{
SysInit();
RCC_CFG();
NVIC_CFG();
GPIO_CFG();
USART1_CFG();
TIM_Input_Capture_CFG();
while(1) ;
} |
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