//From bildr article: http://bildr.org/2012/08/rotary-encoder-arduino/

//Note: This code is for reference only. It may not work!
class RotaryEncoder
{
  public:
  //Identification information
  int encoderPin1;  //Encoder data 1
  int encoderPin2;  //Encoder data 2
  int encoderBtnPin;  //Integrated pushbutton input
  
  //Data processing information
  volatile int lastEncoded;
  //voltaile long encoderValue;
  
  boolean newValue;     //Allows loop program to send serial data outside of interrupt
  boolean rotDirection; //Rotation Direction, CW = 0, CCW = 1
  
  unsigned long lastClickTime; //Stores the last time the button was clicked for determining double clicks
  boolean dblClicked; //Double clicked?
  
  //int lastMSB; //Last most significant bit
  //int lastLSB; //Last least significant bit
  
  //Constructor
  RotaryEncoder(int nPin1, int nPin2, int nPin3);
  
  //Methods
  boolean isNew();
  boolean hasDblClicked();
  void    SendRot();
  void    SendDblClick();
  
};

RotaryEncoder::RotaryEncoder(int nPin1, int nPin2, int nPin3)
{
  encoderPin1 = nPin1;
  encoderPin2 = nPin2;
  encoderBtnPin = nPin3;
  
  lastEncoded = 0;
  newValue = false;
  lastClickTime = 0;
  dblClicked = false;
  
  //lastMSB = 0;
  //lastLSB = 0;
  
  pinMode(encoderPin1, INPUT_PULLUP);
  pinMode(encoderPin2, INPUT_PULLUP);
  pinMode(encoderBtnPin, INPUT_PULLUP);
  
  //call updateEncoder() when any high/low changed seen
  attachInterrupt(encoderPin1, updateEncoder, CHANGE);
  attachInterrupt(encoderPin2, updateEncoder, CHANGE);
  attachInterrupt(encoderBtnPin, encoderBtn_ISR, CHANGE); //Button interrupt service handler @todo
}

boolean RotaryEncoder::isNew()
{
  return newValue;
}

boolean RotaryEncoder::hasDblClicked()
{
  return dblClicked;
}

/* Rotary Encoder Message Format
The format is similar to the other formats used:

[00001]      [0]      [00]      [0]      [0000000]
ID #        Type     Value  Super speed  Don't Care

The ID number, 1, is reserved for the rotary encoder
The type is binary (0)
The value can be: 0 = CW, 1 = CCW, 2 = Double Click
The super speed bit is 1 when the rotary dial is pressed down and held while rotating
It speeds up scrolling by letting the computer know to send multiple rotation messages detent

*/
void RotaryEncoder::SendRot()
{
  newValue = false; //Reset the flag
  
  int message = 0;
  message |= rotDirection;
  message <<= 1; //Shift the value left 1 bit to make room for super speed bit
  message |= digitalRead(encoderBtnPin); //Add in the value of the integrated push button
  message <<= 7; //Shift the value left 7 bits to line it up with the data format
  
  sendMessage(1, 0, message);
  
}

void RotaryEncoder::SendDblClick()
{
  dblClicked = false; //Reset the flag
  sendMessage(1, 0, 0b0000001100000000); //Send a binary 2 in the value position (indicates Dbl Click)
  //Note that we do not care about the super speed bit in this situation
}

RotaryEncoder encoder(P2_0, P2_1, P2_2); //New rotary encoder connected to pins 8-10

void setup()
{
  Serial.begin (9600);
}

void loop()
{
  if(encoder.isNew())
    encoder.SendRot();
    
  if(encoder.hasDblClicked())
    encoder.SendDblClick();
    
}

void sendMessage(int a, int b, int c) //Placeholder function
{
  
}

void updateEncoder()
{
  
  int MSB = digitalRead(encoder.encoderPin1); //MSB = most significant bit
  int LSB = digitalRead(encoder.encoderPin2); //LSB = least significant bit

  int encoded = (MSB << 1) |LSB; //converting the 2 pin value to single number
  int sum  = (encoder.lastEncoded << 2) | encoded; //adding it to the previous encoded value

  if(sum == 0b1101 || sum == 0b0100 || sum == 0b0010 || sum == 0b1011) //CW
  {
    encoder.newValue = true;
    encoder.rotDirection = false; //CW
  }
  if(sum == 0b1110 || sum == 0b0111 || sum == 0b0001 || sum == 0b1000) //CCW
 {
   encoder.newValue = true;
   encoder.rotDirection = true; //CCW
 }

  encoder.lastEncoded = encoded; //store this value for next time
}

//Called when the encoder button is pressed
void encoderBtn_ISR()
{
  /*if(lastClickTime == 0) //Last click time has been reset, this is the first click
    lastClickTime = millis();
  else //This is another click (or bounce?)
  {*/
    unsigned long deltaClickTime = millis()-encoder.lastClickTime;
    if(deltaClickTime >= 100 && deltaClickTime < 300) //Lower/upper limit 1/10 to 3/10 second
      encoder.dblClicked = true; //It's within range, set the flag
    else if(deltaClickTime > 300) //It's over the length of time, reset the lastClickTime
      encoder.lastClickTime = millis();
  //}
}