stm32 旋转编码器

STM32的旋转编码器可以使用TIM（定时器）模块进行读取，具体步骤如下：

1. 配置TIM为编码器模式，使用两个输入捕获通道。
2. 在程序中启动TIM计数器。
3. 在捕获中断中读取TIM的CNT寄存器值，即为编码器当前位置。
4. 根据编码器转动方向，增加或减少计数器值。

下面是一个使用TIM2和TIM3读取编码器值的例子代码：

#include "stm32f4xx.h"

void TIM_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_ICInitTypeDef TIM_ICInitStructure;

    /* TIM2 and TIM3 clock enable */
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 | RCC_APB1Periph_TIM3, ENABLE);

    /* TIM2 and TIM3 configuration in encoder mode */
    TIM_TimeBaseStructure.TIM_Prescaler = 0;
    TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    TIM_TimeBaseStructure.TIM_Prescaler = 0;
    TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

    TIM_EncoderInterfaceConfig(TIM2, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);
    TIM_EncoderInterfaceConfig(TIM3, TIM_EncoderMode_TI12, TIM_ICPolarity_Rising, TIM_ICPolarity_Rising);

    TIM_ICStructInit(&TIM_ICInitStructure);
    TIM_ICInitStructure.TIM_ICFilter = 6;
    TIM_ICInit(TIM2, &TIM_ICInitStructure);
    TIM_ICInit(TIM3, &TIM_ICInitStructure);

    TIM_Cmd(TIM2, ENABLE);
    TIM_Cmd(TIM3, ENABLE);
}

int main(void)
{
    uint16_t encoder_value = 0;
    TIM_Configuration();

    while (1)
    {
        /* Read encoder value */
        encoder_value = TIM_GetCounter(TIM2);
        /* Process encoder value */
    }
}