/*
  * ----------------------------------------------------------------------------------------------------
  * Backyard Brains 2015
  * Muscle SpikerShield Arduino UNO Code for Control header output
  *
  * Code monitors amplitude of EMG envelope, displays EMG strength on LED bar and outputs 
  * (ON/OFF) signal on header output on the Muscle SpikerShield board.
  * 
  * V1.0
  * Written by Marcio Amorim
  * Updated by Stanislav Mircic
  *
  * Tested with Muscle SpikerShield V2.31
  * ----------------------------------------------------------------------------------------------------
  */
  #define NUMBER_OF_LEDS 6                    //Number of LEDs in LED bar
  #define OUTPUT_PIN 2                        //Header output pin
  #define OPERATION_MODE_BUTTON_PIN 7         //pin for button that controls operation mode
  #define SENSITIVITY_BUTTON_PIN 4            //pin for button that controls sensitivity
  #define INDICATOR_LED_PIN 13                //pin for LED that indicates state of output
  
  #define OPERATION_MODE_ON_OFF 1             //operation mode ON/OFF
  #define OPERATION_MODE_FLICKER 2            //operation mode flickering
  
  #define OUTPUT_STATE_ON 1                   //output is in active (HIGH) state
  #define OUTPUT_STATE_OFF 0                  //output is in inactive (LOW) state

  int emgMeasurement = 0;                     //current value of measured EMG
  int buttonState;                            //temporary variable for reading of button state
  
  int outputState = OUTPUT_STATE_OFF;
  int currentOperationMode = 2;

  //EMG saturation values (when EMG reaches this value the output will be activated/deactivated)
  int sensitivities[] = {200, 350, 520, 680, 840, 1000};
  int lastSensitivitiesIndex = 2;             //set initial sensitivity index
  int sensitivity;                            //current sensitivity threshold
  
  byte ledbarHeight = 0;                      //temporary variable for led bar height
  byte ledPins[] = {8, 9, 10, 11, 12, 13};    //pins for LEDs in LED bar


  //-----------------------------------------------------------------------------------
  //   Setup inputs and outputs
  // ----------------------------------------------------------------------------------
  void setup()
  {
    //set realy pin as output
    pinMode(OUTPUT_PIN, OUTPUT);
    
    //set button pins as inputs
    pinMode(OPERATION_MODE_BUTTON_PIN, INPUT);
    pinMode(SENSITIVITY_BUTTON_PIN, INPUT);
  
    //set all pins for LED bar to output
    for(int i = 0; i < NUMBER_OF_LEDS; i++)
    { 
      pinMode(ledPins[i], OUTPUT);
    }
    
    //get the current sensitivity
    sensitivity = sensitivities[lastSensitivitiesIndex];
  }




  //-----------------------------------------------------------------------------------
  //   Main loop
  //
  //   - Checks state of sesitivity button
  //   - Checks state of default-state button
  //   - Measure EMG
  //   - Shows EMG strength on LED bar
  //   - Sets state of the header output (1/0)
  // ----------------------------------------------------------------------------------
  void loop()
  {
    
    //-----------------------  Switch mode of operation  -----------------------------------
    
    buttonState = digitalRead(OPERATION_MODE_BUTTON_PIN);
    if(buttonState == HIGH)
    {
        if(currentOperationMode == OPERATION_MODE_ON_OFF)
        {
            flickeringEffect();
            currentOperationMode = OPERATION_MODE_FLICKER;
        }
        else
        {
            onOffEffect();
            currentOperationMode = OPERATION_MODE_ON_OFF;
        }
    }
    
   //-----------------------  Switch sensitivity ------------------------------------
      
    //check if button is pressed (HIGH)
    if (digitalRead(SENSITIVITY_BUTTON_PIN))
    { 
        turnOffAllLeds();
      
        //increment sensitivity index
        lastSensitivitiesIndex++;
        if(lastSensitivitiesIndex==NUMBER_OF_LEDS)
        {
          lastSensitivitiesIndex = 0;
        }
      
        //get current sensitivity value
        sensitivity = sensitivities[lastSensitivitiesIndex]; 
        
        //light up LED at lastSensitivitiesIndex position for visual feedback
        digitalWrite(ledPins[lastSensitivitiesIndex], HIGH);
       
        //wait user to release button
        while (digitalRead(SENSITIVITY_BUTTON_PIN)) 
        {  
          delay(10);
        }       
        //whait a bit more so that LED light feedback is always visible
        delay(100);        
    }
  
  
    //--------------------------- Measure EMG signal --------------------------------------
    
    emgMeasurement = analogRead(A0);
  
  
    //---------------------- Display EMG strength on LED bar ------------------------------
    
    turnOffAllLeds();
    emgMeasurement= constrain(emgMeasurement, 0, sensitivity);
    ledbarHeight = map(emgMeasurement, 0, sensitivity, 0, NUMBER_OF_LEDS);
    
    for(int k = 0; k < ledbarHeight; k++)
    {
        digitalWrite(ledPins[k], HIGH);
    }
  
  
    //------------------ Control output based on EMG strength ----------------------------
  
     //Control for ON/OFF mode of operation
     if(currentOperationMode == OPERATION_MODE_ON_OFF)
     {
         //If EMG reach threshold toggle current state
         //of output and wait for half the second
         //before next measurement of EMG
         
         if(emgMeasurement >= sensitivity)
         {
             if(outputState == OUTPUT_STATE_OFF)
             {
                 digitalWrite(OUTPUT_PIN, HIGH);
                 outputState = OUTPUT_STATE_ON;
             }
             else
             {
                 digitalWrite(OUTPUT_PIN, LOW);
                 outputState = OUTPUT_STATE_OFF;
             }
             delay(500);
         }
     }
    
    //Control for flickering mode of operation control
    if(currentOperationMode == OPERATION_MODE_FLICKER)
    {
        //If EMG reach threshold turn ON output
        //otherwise turn OFF output
        if(emgMeasurement >= sensitivity )
        {
            digitalWrite(OUTPUT_PIN, HIGH);
            outputState = OUTPUT_STATE_ON;
        }
        else
        {
            digitalWrite(OUTPUT_PIN, LOW);
            outputState = OUTPUT_STATE_OFF;
        }
        delay(20);
    }
    
    //------------------------ Show indicator of output state ----------------------------
    
    if(outputState == OUTPUT_STATE_OFF)
    {
        digitalWrite(INDICATOR_LED_PIN, LOW);
    }
    else
    {
        digitalWrite(INDICATOR_LED_PIN, HIGH);
    }
  } 
  
  
  
  
  //---------------------------------------------------------------------------
  //
  //                 Helper functions
  //
  //---------------------------------------------------------------------------
  
  

  //---------------------------------------------------------------------------
  // Turn OFF all LEDs in LED bar
  //---------------------------------------------------------------------------
  void turnOffAllLeds()
  {
    for(int k = 0; k < NUMBER_OF_LEDS; k++)
    {
      digitalWrite(ledPins[k], LOW);
    }
  }
  
  
  //---------------------------------------------------------------------------
  // Turn ON all LEDs in LED bar
  //---------------------------------------------------------------------------
  void turnOnAllLeds()
  {
    for(int k = 0; k < NUMBER_OF_LEDS; k++)
    {
      digitalWrite(ledPins[k], HIGH);
    }
  }
  
  
  //---------------------------------------------------------------------------
  // Flicker all LEDs in LED bar just that user knows that we are in 
  // flickering mode 
  //---------------------------------------------------------------------------
  void flickeringEffect()
  {
      for(int i=0;i<5;i++)
      {
        turnOnAllLeds();
        delay(100);
        turnOffAllLeds();
        delay(100);
      }
  }
  
  
  //---------------------------------------------------------------------------
  // Flicker ON all LEDs in LED bar whait for half the second and turn it off. 
  // Just that user knows that we are in ON/OFF mode 
  //---------------------------------------------------------------------------
  void onOffEffect()
  {
      turnOnAllLeds();
      delay(500);
      turnOffAllLeds();
  }