STM32F407定时器编码器接口模式

STM32F407定时器编码器接口模式
16位定时器扩展32位

//TIM5初始化为编码器接口模式，读取光栅尺数值
void TIM5_Config(u32 arr,u32 psc)
{
	GPIO_InitTypeDef GPIO_InitStructure;
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	TIM_ICInitTypeDef TIM_ICInitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5,ENABLE);  	//TIM5时钟使能    
	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTF时钟	
	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1; //光栅尺
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//复用功能
	GPIO_InitStructure.GPIO_OType = GPIO_OType_OD; //开漏输出
	GPIO_InitStructure.GPIO_PuPd= GPIO_PuPd_UP; //上拉
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;	//速度100MHz
	GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PD
	
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource0,GPIO_AF_TIM5); //复用为TIM5
	GPIO_PinAFConfig(GPIOA,GPIO_PinSource1,GPIO_AF_TIM5); //复用为TIM5
	
	TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);  
	TIM_TimeBaseStructure.TIM_Prescaler=psc;  //定时器分频
	TIM_TimeBaseStructure.TIM_Period=arr;   //自动重装载值 0xFFFF 65535
	TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1; 	//时钟分频
	TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式
	TIM_TimeBaseInit(TIM5,&TIM_TimeBaseStructure);  //初始化TIM5
	
  //编码器模式1 – 根据TI1FP1的电平，计数器在TI2FP2的边沿向上/下计数。
	TIM_EncoderInterfaceConfig(TIM5,TIM_EncoderMode_TI1,TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);  //编码器接口模式配置
	TIM_ICStructInit(&TIM_ICInitStructure);  //默认值赋值
	TIM_ICInitStructure.TIM_ICFilter =0x2;   //滤波 0x0~0xF  
	TIM_ICInit(TIM5, &TIM_ICInitStructure);  //初始化

	TIM_ClearFlag(TIM5, TIM_FLAG_Update);//清除标志位
	TIM_ITConfig(TIM5, TIM_IT_Update, ENABLE); //更新中断 
 
	TIM_SetCounter(TIM5,0);  //计数器清零
	TIM_Cmd(TIM5, ENABLE); 
	
	NVIC_InitStructure.NVIC_IRQChannel=TIM5_IRQn;   //添加中断函数
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0x02; //抢占优先级2
	NVIC_InitStructure.NVIC_IRQChannelSubPriority=0x03; //子优先级3
	NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
	NVIC_Init(&NVIC_InitStructure); 	
}

volatile int16_t N=0;
void TIM5_IRQHandler(void)   //溢出中断
{
	if(TIM_GetITStatus(TIM5,TIM_IT_Update)==SET) //中断标志位
	{
		      if((TIM5->CR1 & TIM_CR1_DIR) == TIM_CR1_DIR)//向下计数 DIR=1
          {          
                     N--;               
          }
          else if((TIM5->CR1 & TIM_CR1_DIR) == 0)//向上计数 DIR=0
          {
                     N++;            
          }
	}
	TIM_ClearITPendingBit(TIM5,TIM_IT_Update);  //清除中断标志位    
}

int main(void)
{ 
	u32 data;

	TIM5_Config(0XFFFF,0); //定时器初始化     16位自动加载

	while(1)
	{
			data=N * 65536 + TIM5->CNT;     //读取编码器值
		    data=GetENCODECounter(data);  //编码器值反方向处理
		
			delay_ms(200);  
	}   
}

//编码器反方向转换
//输出0xX0000000  正方向X=0  反方向X=1
u32 GetENCODECounter(u32 count)  //编码器反方向数值转换
{
	if(count>0X80000000)     //负方向
	{
		count=0XFFFFFFFF-count;  //
		count=count | 0X80000000 ;			
	}
	return count;
}