stm32f2xx与stm32f10x 在正交编码器应用关于定时器初始化中的区别

如题，送给自己做警醒。

如果关于正交编码器，平台stm32f103推荐参考代码：
http://www.openedv.com/posts/list/44775.htm
 

注意：

如果stm32f2xx系列上面的网址的代码要做适当修改。

以下说重点：stm32f2xx系列，在调试中对GPIO的初始化，切记选择GPIO_Mode_AF模式，即端口复用。

随后，要做端口映射处理，即调用：GPIO_PinAFConfig（）函数。

这2个方式不选择，timer是不会有反应的

本人是stm32f207,花了4天惨痛代价。

以下贴代码：

/* Private define ------------------------------------------------------------*/
#define ENCODER_TIMER                TIM3  // Encoder unit connected to TIM3
#define ENCODER_PPR           (u16)(1000)   // number of pulses per revolution
#define SPEED_BUFFER_SIZE               8

#define COUNTER_RESET   (u16)10
#define ICx_FILTER      (u8) 6 // 6<-> 670nsec

#define TIMx_PRE_EMPTION_PRIORITY 0x0F
#define TIMx_SUB_PRIORITY 0x0F

*******************************************************************************
* Function Name : ENC_Init
* Description : General Purpose Timer x set-up for encoder speed/position
* sensors
* Input : None
* Output : None
* Return : None
*******************************************************************************/
void Encoder_Init(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_ICInitTypeDef TIM_ICInitStructure;

/* Encoder unit connected to TIM3, 4X mode */
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

/* TIM3 clock source enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/* Enable GPIOC, clock */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
//GPIO_Init
GPIO_StructInit(&GPIO_InitStructure);
/* Configure PC.06,07 as encoder input */
GPIO_InitStructure.GPIO_Pin = INTA_PIN | INTB_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; //这个地方注意
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOC, &GPIO_InitStructure);

/* Connect TIM3 pins to AF2 */
GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_TIM3); //这个地方注意
GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_TIM3); //这个地方注意

/* Enable the TIM3 Update Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = TIMx_PRE_EMPTION_PRIORITY;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = TIMx_SUB_PRIORITY;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

/* Timer configuration in Encoder mode */
TIM_DeInit(ENCODER_TIMER);
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);

TIM_TimeBaseStructure.TIM_Prescaler = 0x0; // No prescaling
TIM_TimeBaseStructure.TIM_Period = 0x0F;//(4*ENCODER_PPR)-1;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(ENCODER_TIMER, &TIM_TimeBaseStructure);

TIM_EncoderInterfaceConfig(ENCODER_TIMER, TIM_EncoderMode_TI1,
TIM_ICPolarity_Falling, TIM_ICPolarity_Falling);
TIM_ICStructInit(&TIM_ICInitStructure);
TIM_ICInitStructure.TIM_ICFilter = ICx_FILTER; //--?--
TIM_ICInit(ENCODER_TIMER, &TIM_ICInitStructure);

// Clear all pending interrupts
TIM_ClearFlag(ENCODER_TIMER, TIM_FLAG_Update);
TIM_ITConfig(ENCODER_TIMER, TIM_IT_Update, ENABLE);
//Reset counter
//ENCODER_TIMER->CNT = COUNTER_RESET;

ENC_Clear_Speed_Buffer();

TIM_Cmd(ENCODER_TIMER, ENABLE);
}

/*******************************************************************************
* Function Name  : TIM3_IRQHandler
* Description    : This function handles TIMx Update interrupt request.
                   Encoder unit connected to TIM3
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void TIM3_IRQHandler(void)
{  
    /* Clear the interrupt pending flag */
    TIM_ClearFlag(ENCODER_TIMER, TIM_FLAG_Update);

}