update code and doc for rotary encoders examples

Author: LouWii

Test-rotary-encoder-MIDI/README.md

@@ -15,4 +15,8 @@ The code requires 3 libraries:
 
 ### MIDI_CONTROLLER
 
-This library makes it really easy to create MIDI controls from buttons, switches, potentiometers, faders, sensors, rotary encoders... The only step required is to create your control, apply some settings to it and the library will take care of detecting and sending commands to the computer. That library also makes the Arduino Leonardo (and other compatible boards) to be detected as a MIDI device on your computer. [See full documentation](https://github.com/tttapa/MIDI_controller/wiki/Library-documentation)
+This library makes it really easy to create MIDI controls from buttons, switches, potentiometers, faders, sensors, rotary encoders... The only step required is to create your control, apply some settings to it and the library will take care of detecting and sending commands to the computer. That library also makes the Arduino Leonardo (and other compatible boards) to be detected as a MIDI device on your computer. [See full documentation](https://github.com/tttapa/MIDI_controller/wiki/Library-documentation).
+
+As you can see in the code, we almost do nothing for the rotary encoder to work, no change detection, no debouncing, the library does everything for us. 👍
+
+My goal was to use this control in Lightroom, via [MIDI2LR](https://github.com/rsjaffe/MIDI2LR). MIDI2LR will need a specific setting for a rotary encoder to work properly, see the comment in the code file.

Test-rotary-encoder-MIDI/Test-rotary-encoder-MIDI.ino

@@ -6,7 +6,7 @@
 
 /*
   This is an example of the "RotaryEncoder" class of the MIDI_controller library.
-  Connect the A and B pins of the encoder to 2 interrupt pins (2 and 3). 
+  Connect the A and B pins of the encoder to 2 interrupt pins (0 and 1).
   It's recommended to use 100nF capacitors between the A and B pins and ground (hardware debounce).
   Connect the common (C) pin to the ground. Pull-up resistors are not necessary, since the internal ones will be used.
   Map the control change message 0x14 to the right control in your DJ or DAW software, 
@@ -36,7 +36,8 @@ const uint8_t Channel = 1;       // MIDI channel 1
 const uint8_t Controller = 0x14; // MIDI Control Change controller number https://www.midi.org/specifications/item/table-3-control-change-messages-data-bytes-2
 const int speedMultiply = 1; // No change in speed of the encoder (number of steps is multiplied by 1)
 
-RotaryEncoder encoder(1, 0, Controller, Channel, speedMultiply, NORMAL_ENCODER, TWOS_COMPLEMENT);
+// If the control is reversed, inverse the 2 pins 0 and 1 here or directly on your board
+RotaryEncoder encoder(0, 1, Controller, Channel, speedMultiply, NORMAL_ENCODER, TWOS_COMPLEMENT);
 
 // Instantiate a MIDI interface that sends debug messages to the USB Serial port (Serial Monitor)
 //USBDebugMIDI_Interface midiInterface(115200);

Test-rotary-encoder-volume/README.md

@@ -20,4 +20,4 @@ The encoder library allows us to easily interact with the encoder, without any h
 
 Project-HID allows us to make the Arduino Leonardo appear as a *consumer* USB product on a computer, which is the only way to control volume on Windows machine (and probably OSX too). See [the documentation](https://github.com/NicoHood/HID/wiki/Consumer-API) for more information about `Consumer`. The library has some pre-defined constants for common USB codes, but you can send pretty much everything you want.
 
-For more information about *consumer* USB codes, check the official USB documentation on HID usage tables[https://www.usb.org/document-library/hid-usage-tables-112](https://www.usb.org/document-library/hid-usage-tables-112). Codes for *consumer* hardware are on page 75).
+For more information about *consumer* USB codes, check the official USB documentation on HID usage tables [https://www.usb.org/document-library/hid-usage-tables-112](https://www.usb.org/document-library/hid-usage-tables-112). Codes for *consumer* hardware are on page 75).

Test-rotary-encoder-volume/Test-rotary-encoder-volume.ino

@@ -8,10 +8,19 @@
 // Might cause problems if other libs or code uses attachInterrupt()
 #define ENCODER_OPTIMIZE_INTERRUPTS
 
+// If the control is reversed, inverse the 2 pins here or directly on your board
 Encoder encoder(0, 1);
 
-long encod = 0;
-const int step = 2;
+const int debounceDelay = 20;
+
+long encoderCurrentValue;
+long encoderLastChange = 0;
+// The step allows us to change the "sensibility" of the encoder, we "detect" a change only if the encoder has changed n steps
+//  The more steps, the least sensible
+const int step = 1;
+
+long currentTime;
+long encoderNewValue;
 
 void setup() {
   Serial.begin(9600);
@@ -20,19 +29,21 @@ void setup() {
 }
 
 void loop() {
-  long newEnc;
-
-  newEnc = encoder.read();
-  if ( abs((encod - newEnc)) == step ) {
-
-    // Control sound?
-    if (encod < newEnc) {
-      Consumer.write(MEDIA_VOLUME_UP);
-    } else {
-      Consumer.write(MEDIA_VOLUME_DOWN);
+  currentTime = millis();
+
+  encoderNewValue = encoder.read();
+  if ( abs((encoderCurrentValue - encoderNewValue)) >= step ) {
+
+    if (currentTime - encoderLastChange > debounceDelay) {
+      if (encoderCurrentValue < encoderNewValue) {
+        Consumer.write(MEDIA_VOLUME_UP);
+        Serial.println("Volume Up");
+      } else {
+        Consumer.write(MEDIA_VOLUME_DOWN);
+        Serial.println("Volume Down");
+      }
+      encoderCurrentValue = encoderNewValue;
+      encoderLastChange = currentTime;
     }
-    encod = newEnc;
-    Serial.println(newEnc);
-    delay(20);
   }
 }

Test-rotary-encoder/README.md

@@ -11,6 +11,8 @@ If you don't know what a rotary encoder is, the official Arduino playground has
 The code requires 1 library:
 * encoder [https://www.pjrc.com/teensy/td_libs_Encoder.html](https://www.pjrc.com/teensy/td_libs_Encoder.html)
 
+The code contains comments that should allow you to understand everything. If you're curious about *debouncing*, check [the official Arduino debounce documentation](https://www.arduino.cc/en/Tutorial/Debounce).
+
 ### Encoder
 
-The encoder library allows us to easily interact with the encoder, without any hassle.
+The encoder library allows us to easily interact with the encoder, without any hassle.

Test-rotary-encoder/Test-rotary-encoder.ino

@@ -5,28 +5,47 @@
 // Might cause problems if other libs or code uses attachInterrupt()
 #define ENCODER_OPTIMIZE_INTERRUPTS
 
-Encoder encoder(1, 0);
+// If the control is reversed, inverse the 2 pins here or directly on your board
+Encoder encoder(0, 1);
 
-long encod;
-const int step = 2;
+const int debounceDelay = 20;
+
+long encoderCurrentValue;
+long encoderLastChange = 0;
+// The step allows us to change the "sensibility" of the encoder, we "detect" a change only if the encoder has changed n steps
+//  The more steps, the least sensible
+const int step = 1;
+
+long currentTime;
+long encoderNewValue;
 
 void setup() {
   Serial.begin(9600);
 }
 
 void loop() {
-  long newEnc;
-
-  newEnc = encoder.read();
-  if ( abs((encod - newEnc)) == step ) {
-
-    if (encod < newEnc) {
-      // Going up
-    } else {
-      // Going down
+  currentTime = millis();
+
+  encoderNewValue = encoder.read();
+  if ( abs((encoderCurrentValue - encoderNewValue)) >= step ) {
+    // Debouncing: consider a change of state is valid if it happens after x milliseconds
+    //  If not, we consider it as noise and do nothing
+    if (currentTime - encoderLastChange > debounceDelay) {
+      if (encoderCurrentValue < encoderNewValue) {
+        // Going up
+      } else {
+        // Going down
+      }
+      Serial.print("Time: ");
+      Serial.print(currentTime);
+      Serial.print("; Last time: ");
+      Serial.print(encoderLastChange);
+      Serial.print("; Encoder value: ");
+      Serial.print(encoderNewValue);
+      Serial.print("; Encoder last value: ");
+      Serial.println(encoderCurrentValue);
+      encoderCurrentValue = encoderNewValue;
+      encoderLastChange = currentTime;
     }
-    encod = newEnc;
-    Serial.println(newEnc);
-    delay(20);
   }
 }