Simple software de-bounce in RotaryEncoder::_encoder_ISR()

[martind69]

Hi, i had a problem with bouncy china knob's

maybe you can update your code like this. I copied from RotaryEncoder::_button_ISR() and changed to micros()

void ARDUINO_ISR_ATTR RotaryEncoder::_encoder_ISR()
{
  /**
   * Almost all of this came from a blog post by Garry on GarrysBlog.com:
   * https://garrysblog.com/2021/03/20/reliably-debouncing-rotary-encoders-with-arduino-and-esp32/
   *
   * Read more about how this works here:
   * https://www.best-microcontroller-projects.com/rotary-encoder.html
   */

  static uint8_t _previousAB = 3;
  static int8_t _encoderPosition = 0;
  static unsigned long _lastInterruptTime = 0;
  static long _stepValue;
  bool valueChanged = false;

  // Simple software de-bounce
  if( ( micros() - _lastInterruptTime ) < 100 )
    return;

  _previousAB <<= 2;  // Remember previous state

  if( digitalRead( encoderPinA ) ) _previousAB |= 0x02; // Add current state of pin A
  if( digitalRead( encoderPinB ) ) _previousAB |= 0x01; // Add current state of pin B

  _encoderPosition += encoderStates[( _previousAB & 0x0f )];


  /**
   * Based on how fast the encoder is being turned, we can apply an acceleration factor
   */

  unsigned long speed = micros() - _lastInterruptTime;

  if( speed > 40000 )                              // Greater than 40 milliseconds
    _stepValue = this->stepValue;                  // Increase/decrease by 1 x stepValue

  else if( speed > 20000 )                         // Greater than 20 milliseconds
    _stepValue = ( this->stepValue <= 9 ) ?        // Increase/decrease by 3 x stepValue
      this->stepValue : ( this->stepValue * 3 )    // But only if stepValue > 9
    ;

  else                                             // Faster than 20 milliseconds
    _stepValue = ( this->stepValue <= 100 ) ?      // Increase/decrease by 10 x stepValue
      this->stepValue : ( this->stepValue * 10 )   // But only if stepValue > 100
    ;


  /**
   * Update counter if encoder has rotated a full detent
   * For the following comments, we'll assume it's 4 steps per detent
   * The tripping point is `STEPS - 1` (so, 3 in this example)
   */

  if( _encoderPosition > encoderTripPoint )        // Four steps forward
  {
    this->currentValue += _stepValue;
    valueChanged = true;
  }
  else if( _encoderPosition < -encoderTripPoint )  // Four steps backwards
  {
    this->currentValue -= _stepValue;
    valueChanged = true;
  }

  if( valueChanged )
  {
    encoderChangedFlag = true;

    // Reset our "step counter"
    _encoderPosition = 0;

    // Remember current time so we can calculate speed
    _lastInterruptTime = micros();
  }
}

[MaffooClock]

My apologies for letting this get cold!

So you're proposing the following patch:

--- ESP32RotaryEncoder.cpp	2025-01-23 08:49:43
+++ ESP32RotaryEncoder-changed.cpp	2025-01-23 08:56:51
@@ -328,11 +328,14 @@
   static int8_t _encoderPosition = 0;
   static unsigned long _lastInterruptTime = 0;
   static long _stepValue;
-
   bool valueChanged = false;

-  _previousAB <<=2;  // Remember previous state
+  // Simple software de-bounce
+  if( ( micros() - _lastInterruptTime ) < 100 )
+    return;

+  _previousAB <<= 2;  // Remember previous state
+
   if( digitalRead( encoderPinA ) ) _previousAB |= 0x02; // Add current state of pin A
   if( digitalRead( encoderPinB ) ) _previousAB |= 0x01; // Add current state of pin B

\ No newline at end of file
@@ -343,12 +346,12 @@
    * Based on how fast the encoder is being turned, we can apply an acceleration factor
    */

-  unsigned long speed = millis() - _lastInterruptTime;
+  unsigned long speed = micros() - _lastInterruptTime;

-  if( speed > 40 )                                 // Greater than 40 milliseconds
+  if( speed > 40000 )                              // Greater than 40 milliseconds
     _stepValue = this->stepValue;                  // Increase/decrease by 1 x stepValue

-  else if( speed > 20 )                            // Greater than 20 milliseconds
+  else if( speed > 20000 )                         // Greater than 20 milliseconds
     _stepValue = ( this->stepValue <= 9 ) ?        // Increase/decrease by 3 x stepValue
       this->stepValue : ( this->stepValue * 3 )    // But only if stepValue > 9
     ;
\ No newline at end of file
@@ -384,6 +387,6 @@
     _encoderPosition = 0;

     // Remember current time so we can calculate speed
-    _lastInterruptTime = millis();
+    _lastInterruptTime = micros();
   }
 }
\ No newline at end of file

...appears to be reasonable enough. I'll commit this change after I've tested.