Adding new example of how to check for left or right turns

This library primarily intends for you to track an integer value between a given minimum and maximum value as the knob is turned.

However, in this example we show you how to fire an event when the knob is turned left or right instead of tracking an integer value.

examples/LeftOrRight/LeftOrRight/LeftOrRight.ino

@@ -0,0 +1,120 @@
+/**
+ * ESP32RotaryEncoder: LeftOrRight.ino
+ * 
+ * This is a simple example of how to track whether the knob was
+ * turned left or right instead of tracking a numeric value
+ * 
+ * Created 1 November 2023
+ * By Matthew Clark
+ */
+
+#include <ESP32RotaryEncoder.h>
+
+// Change these to the actual pin numbers that
+// you've connected your rotary encoder to
+#define DI_ENCODER_A   27 // CLK
+#define DI_ENCODER_B   14 // DT
+#define DI_ENCODER_SW  12
+#define DO_ENCODER_VCC 13
+
+
+RotaryEncoder rotaryEncoder( DI_ENCODER_A, DI_ENCODER_B, DI_ENCODER_SW, DO_ENCODER_VCC );
+
+// Used by the `loop()` to know when to
+// fire  an event when the knob is turned
+volatile bool turnedRightFlag = false;
+volatile bool turnedLeftFlag = false;
+
+void turnedRight()
+{
+  Serial.println( "Right ->" );
+
+  // Set this back to false so we can watch for the next move
+  turnedRightFlag = false;
+}
+
+void turnedLeft()
+{
+  Serial.println( "<- Left" );
+
+  // Set this back to false so we can watch for the next move
+  turnedLeftFlag = false;
+}
+
+void knobCallback( int value )
+{
+  // See the note in the `loop()` function for
+  // an explanation as to why we're setting
+  // boolean values here instead of running
+  // functions directly.
+
+  // Don't do anything if either flag is set;
+  // it means we haven't taken action yet
+  if( turnedRightFlag || turnedLeftFlag )
+    return;
+
+  // Set a flag that we can look for in `loop()`
+  // so that we know we have something to do
+  switch( value )
+  {
+    case 1:
+      turnedRightFlag = true;
+    break;
+
+    case -1:
+      turnedLeftFlag = true;
+    break;
+  }
+
+  // Override the tracked value back to 0 so that 
+  // we can continue tracking right/left events
+  rotaryEncoder.setEncoderValue( 0 );
+}
+
+void buttonCallback()
+{
+	Serial.println( "boop!" );
+}
+
+void setup()
+{
+	Serial.begin( 115200 );
+
+  // This tells the library that the encoder has its own pull-up resistors
+  rotaryEncoder.setEncoderType( EncoderType::HAS_PULLUP );
+
+  // The encoder will only return -1, 0, or 1, and will not wrap around.
+  rotaryEncoder.setBoundaries( -1, 1, false );
+
+  // The function specified here will be called every time the knob is turned
+	// and the current value will be passed to it
+  rotaryEncoder.onTurned( &knobCallback );
+
+	// The function specified here will be called every time the button is pushed
+  rotaryEncoder.onPressed( &buttonCallback );
+
+	// This is where the inputs are configured and the interrupts get attached
+  rotaryEncoder.begin();
+}
+
+void loop()
+{
+  // Check to see if a flag is set (is true), and if so, run a function.
+  //
+  // Why do it like this instead of within the `knobCallback()` function?
+  //
+  // Because the `knobCallback()` function is executed by a internal
+  // timer ISR (interrupt service routine), which needs to be fast and
+  // lean, so setting a boolean is the fastest way, and then let the main
+  // `loop()` do the heavy-lifting.
+  //
+  // If you were to let the `knobCallback()` function do all the work,
+  // there's a chance you'd have issues with WiFi or Bluetooth connections,
+  // or even cause the MCU to crash.
+
+  if( turnedRightFlag )
+    turnedRight();
+
+  else if( turnedLeftFlag )
+    turnedLeft();
+}

library.json

@@ -25,6 +25,11 @@
       "name": "Two Rotary Encoders",
       "base": "examples/TwoRotaryEncoders",
       "files": [ "TwoRotaryEncoders.ino" ]
+    },
+    {
+      "name": "Left or Right",
+      "base": "examples/LeftOrRight",
+      "files": [ "LeftOrRight.ino" ]
     }
   ],
   "frameworks": "arduino",