STM32F103CBT6搭配EC11旋转编码器输入不可靠问题求助

云原生阿岚

2026-7-7

问题描述

基于STM32F103CBT6设计HID游戏手柄PCB，配置16MHz晶振、18个按键、4个EC11旋转编码器。按键功能正常，但编码器存在以下问题：

部分旋转动作未被识别
偶尔出现引脚跳变
甚至双引脚同时触发输入

编码器接线：中间引脚接地，另外两引脚接MCU引脚：

编码器1：PB8/PB9
编码器2：PB10/PB11
编码器3：PB12/PB13
编码器4：PB14/PB15
所有引脚配置为带内部上拉的GPIO输入。

尝试过两种方案均效果不佳：

轮询方式读取编码器状态（代码见下方），识别效果差
单编码器中断方案（仅实现单个编码器），设一个引脚为下降沿中断，另一个为GPIO输入，仍存在旋转时输入跳变问题

原轮询代码

#define ROT_PINS 8
#define ROT_BUTTONS 8

GPIO_TypeDef* rotary_ports[ROT_BUTTONS] = {GPIOB, GPIOB, GPIOB, GPIOB, GPIOB, GPIOB, GPIOB, GPIOB};
uint16_t rotary_pins[ROT_BUTTONS] = {GPIO_PIN_8, GPIO_PIN_9, GPIO_PIN_10, GPIO_PIN_11, GPIO_PIN_12, GPIO_PIN_13, GPIO_PIN_14, GPIO_PIN_15};

struct ButtonReport {
    uint8_t report_id;
    uint32_t buttons; 
} __attribute__((packed));

struct ButtonReport buttonReport;

void SCANALL(void)
{
    uint8_t targetRow, targetCol;

    // Clear the buttonReport struct
    memset(&buttonReport, 0, sizeof(buttonReport));

    // Scan encoders (knoppen 1-8)
    for (int i = 0; i < 8; i++) {
        uint8_t rotaryStatus = HAL_GPIO_ReadPin(rotary_ports[i], rotary_pins[i]);
        if (rotaryStatus == GPIO_PIN_RESET) {
            buttonReport.buttons |= (1 << i);
        } else {
            buttonReport.buttons &= ~(1 << i);
        }
    }
    // Stuur het rapport met de knopstatussen
    buttonReport.report_id = 1; // Stel het rapport-ID in als dat nodig is
    USBD_CUSTOM_HID_SendReport(&hUsbDeviceFS, (uint8_t*)&buttonReport, sizeof(buttonReport));
}

原中断代码

struct ButtonReport {
    uint8_t report_id;
    uint32_t buttons;
} __attribute__((packed));

struct ButtonReport buttonReport;

int encoderState = 0;
int lastEncoderState = 0;

void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
    if (GPIO_Pin == GPIO_PIN_8 || GPIO_Pin == GPIO_PIN_9) {
        encoderState = (HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_8) << 1) | HAL_GPIO_ReadPin(GPIOB, GPIO_PIN_9);
        int encoderChange = lastEncoderState - encoderState;

        // Clear button status initially
        buttonReport.buttons = 0;

        if (encoderChange == 1 || encoderChange == -3) {
            // Clockwise rotation - Simulate Button 1 press
            buttonReport.report_id = 1; // Set the report ID (if required)
            buttonReport.buttons |= 0x01; // Set Button 1 as pressed
        } else if (encoderChange == -1 || encoderChange == 3) {
            // Counterclockwise rotation - Simulate Button 2 press
            buttonReport.report_id = 1; // Set the report ID (if required)
            buttonReport.buttons |= 0x02; // Set Button 2 as pressed
        }

        lastEncoderState = encoderState;

        // Send the HID report to the PC
        USBD_CUSTOM_HID_SendReport(&hUsbDeviceFS, (uint8_t*)&buttonReport, sizeof(buttonReport));
    }
}

static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();

  /*Configure GPIO pins : PB10 PB12 PB14 PB8 */
  GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_12|GPIO_PIN_14|GPIO_PIN_8;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_FALLING;

  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /*Configure GPIO pins : PB11 PB13 PB15 PB9 */
  GPIO_InitStruct.Pin = GPIO_PIN_11|GPIO_PIN_13|GPIO_PIN_15|GPIO_PIN_9;
  GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  /* EXTI interrupt init*/
  HAL_NVIC_SetPriority(EXTI9_5_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(EXTI9_5_IRQn);

  HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);

/* USER CODE BEGIN MX_GPIO_Init_2 */
/* USER CODE END MX_GPIO_Init_2 */
}

解决建议

硬件层面优化

增加硬件滤波电路：EC11编码器的A、B输出引脚与GND之间并联100nF陶瓷电容，或在引脚到MCU之间串联1kΩ电阻+100nF电容组成RC滤波，抑制机械抖动和电磁干扰导致的信号跳变。
优化PCB布线：编码器走线尽量短，远离电源、晶振等干扰源；避免A、B引脚走线平行过长，减少串扰；采用大面积地平面，降低接地阻抗。
排查编码器硬件质量：更换不同批次/品牌的EC11编码器测试，排除机械触点磨损、内部结构不良导致的信号异常。

软件层面优化

1. 轮询方案改进（适合低转速场景）

原轮询代码错误地将编码器的A/B引脚当作独立按键处理，未利用相位关系识别旋转，也无消抖逻辑。改进方向：

同时读取每个编码器的A/B引脚状态，通过相位变化判断旋转方向
增加软件消抖，连续多次读取状态一致才判定有效
设置5-10ms的轮询周期，平衡响应速度与抗干扰能力

改进后的轮询示例代码：

#define ENCODER_COUNT 4
typedef struct {
    GPIO_TypeDef* portA;
    uint16_t pinA;
    GPIO_TypeDef* portB;
    uint16_t pinB;
    uint8_t lastState;
    int16_t count;
} Encoder_t;

Encoder_t encoders[ENCODER_COUNT] = {
    {GPIOB, GPIO_PIN_8, GPIOB, GPIO_PIN_9, 0, 0},
    {GPIOB, GPIO_PIN_10, GPIOB, GPIO_PIN_11, 0, 0},
    {GPIOB, GPIO_PIN_12, GPIOB, GPIO_PIN_13, 0, 0},
    {GPIOB, GPIO_PIN_14, GPIOB, GPIO_PIN_15, 0, 0}
};

struct ButtonReport buttonReport;

void SCAN_ENCODERS(void) {
    memset(&buttonReport, 0, sizeof(buttonReport));
    buttonReport.report_id = 1;

    for(int i=0; i<ENCODER_COUNT; i++){
        uint8_t currA = HAL_GPIO_ReadPin(encoders[i].portA, encoders[i].pinA);
        uint8_t currB = HAL_GPIO_ReadPin(encoders[i].portB, encoders[i].pinB);
        uint8_t currState = (currA << 1) | currB;

        if(currState != encoders[i].lastState){
            HAL_Delay(1); // 1ms消抖延时
            currA = HAL_GPIO_ReadPin(encoders[i].portA, encoders[i].pinA);
            currB = HAL_GPIO_ReadPin(encoders[i].portB, encoders[i].pinB);
            currState = (currA << 1) | currB;
            if(currState == encoders[i].lastState) continue;

            uint8_t transition = (encoders[i].lastState << 2) | currState;
            switch(transition){
                case 0b0001: case 0b0111: case 0b1110: case 0b1000:
                    encoders[i].count++;
                    buttonReport.buttons |= (1 << (i*2));
                    break;
                case 0b0010: case 0b1011: case 0b1101: case 0b0100:
                    encoders[i].count--;
                    buttonReport.buttons |= (1 << (i*2 + 1));
                    break;
                default: break;
            }
            encoders[i].lastState = currState;
        }
    }
    USBD_CUSTOM_HID_SendReport(&hUsbDeviceFS, (uint8_t*)&buttonReport, sizeof(buttonReport));
}

2. 中断方案改进

原中断代码仅监听单引脚下降沿，易丢失相位变化，且未做消抖处理。改进方向：

所有编码器A/B引脚设置为双边沿中断，确保捕获全部相位变化
添加时间戳消抖，过滤间隔小于5ms的重复中断
中断中仅更新编码器状态，HID报告发送放在主循环或定时器中断中处理，避免中断阻塞
使用状态机跟踪A/B相位变化，准确识别旋转方向

改进后的中断示例代码：

#define ENCODER_COUNT 4
typedef struct {
    uint8_t lastState;
    int16_t count;
    uint32_t lastIntTime;
} Encoder_t;

Encoder_t encoders[ENCODER_COUNT] = {0};
struct ButtonReport buttonReport;

// 初始化1ms定时器用于HID报告更新
void MX_TIM2_Init(void) {
    TIM_HandleTypeDef htim2;
    htim2.Instance = TIM2;
    htim2.Init.Prescaler = 16000-1;
    htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
    htim2.Init.Period = 1-1;
    htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    HAL_TIM_Base_Init(&htim2);
    HAL_TIM_Base_Start_IT(&htim2);
}

// 定时器回调：定期发送HID报告
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim) {
    if(htim->Instance == TIM2){
        memset(&buttonReport, 0, sizeof(buttonReport));
        buttonReport.report_id = 1;

        for(int i=0; i<ENCODER_COUNT; i++){
            if(encoders[i].count > 0){
                buttonReport.buttons |= (1 << (i*2));
                encoders[i].count--;
            }else if(encoders[i].count < 0){
                buttonReport.buttons |= (1 << (i*2 + 1));
                encoders[i].count++;
            }
        }
        USBD_CUSTOM_HID_SendReport(&hUsbDeviceFS, (uint8_t*)&buttonReport, sizeof(buttonReport));
    }
}

// EXTI中断回调
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin) {
    uint32_t currTime = HAL_GetTick();
    Encoder_t* currEncoder = NULL;
    uint8_t currA, currB, currState;

    switch(GPIO_Pin){
        case GPIO_PIN_8: case GPIO_PIN_9: currEncoder = &encoders[0]; break;
        case GPIO_PIN_10: case GPIO_PIN_11: currEncoder = &encoders[1]; break;
        case GPIO_PIN_12: case GPIO_PIN_13: currEncoder = &encoders[2]; break;
        case GPIO_PIN_14: case GPIO_PIN_15: currEncoder = &encoders[3]; break;
        default: return;
    }

    if(currTime - currEncoder->lastIntTime < 5) return;
    currEncoder->lastIntTime = currTime;

    if(GPIO_Pin % 2 == 0){
        currA = HAL_GPIO_ReadPin(GPIOB, GPIO_Pin);
        currB = HAL_GPIO_ReadPin(GPIOB, GPIO_Pin + 1);
    }else{
        currB = HAL_GPIO_ReadPin(GPIOB, GPIO_Pin);
        currA = HAL_GPIO_ReadPin(GPIOB, GPIO_Pin - 1);
    }
    currState = (currA << 1) | currB;

    uint8_t transition = (currEncoder->lastState << 2) | currState;
    switch(transition){
        case 0b0001: case 0b0111: case 0b1110: case 0b1000:
            currEncoder->count++;
            break;
        case 0b0010: case 0b1011: case 0b1101: case 0b0100:
            currEncoder->count--;
            break;
        default: break;
    }
    currEncoder->lastState = currState;
}

// 修改GPIO初始化：所有编码器引脚设为双边沿中断
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();

  GPIO_InitStruct.Pin = GPIO_PIN_8|GPIO_PIN_9|GPIO_PIN_10|GPIO_PIN_11|GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15;
  GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING_FALLING;
  GPIO_InitStruct.Pull = GPIO_PULLUP;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

  HAL_NVIC_SetPriority(EXTI9_5_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(EXTI9_5_IRQn);

  HAL_NVIC_SetPriority(EXTI15_10_IRQn, 1, 0);
  HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
}

3. 其他优化点

HID报告优化：将编码器映射为HID轴（如滚轮轴、X/Y轴），而非模拟按键，能更平滑处理连续旋转，避免按键触发频率限制。
调试辅助：添加串口打印，输出编码器的A/B状态、旋转计数等信息，快速定位跳变或漏识别的具体原因。

内容的提问来源于stack exchange，提问作者Djowwie

STM32F103CBT6搭配EC11旋转编码器输入不可靠问题求助

原轮询代码 #

原中断代码 #

硬件层面优化 #

软件层面优化 #

1. 轮询方案改进（适合低转速场景） #

2. 中断方案改进 #

3. 其他优化点 #