完整写一个STM32的旋转编码器初始化代码

以下是一个简单的STM32旋转编码器初始化代码示例，使用TIM模块实现：

#include "stm32f4xx.h"

void Encoder_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_ICInitTypeDef TIM_ICInitStructure;
    
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
    
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
    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(GPIOA, &GPIO_InitStructure);
    
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_TIM1);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_TIM1);
    
    TIM_TimeBaseStructure.TIM_Prescaler = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_Period = 65535;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
    
    TIM_EncoderInterfaceConfig(TIM1, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);
    
    TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
    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(TIM1, &TIM_ICInitStructure);
    
    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(TIM1, &TIM_ICInitStructure);
    
    TIM_SetCounter(TIM1, 0);
    TIM_Cmd(TIM1, ENABLE);
}

代码中使用了TIM1模块，将PA8和PA9引脚配置为复用功能，对应的复用功能为TIM1_CH1和TIM1_CH2。使用TIM_EncoderInterfaceConfig函数配置编码器模式为TI1和TI2，同时设置计数器的方向为正向。最后，使用TIM_ICInit函数初始化TIM1_CH1和TIM1_CH2引脚的输入捕获功能，设置捕获极性为上升沿，并将捕获时钟预分频器设置为1，过滤器设置为0。最后，使用TIM_SetCounter函数将计数器清零，使能TIM1计数器。