/*
We managed to control three leds with keyboard by using the function Serial.read().
The commands are sent to arduino through USB serial port.
 
 */


// pins used
int ledpin1 = 9;
int ledpin2 = 10;
int ledpin3 = 11;

// value of Serial.read()
int val;

// Store the value of Serial.read() separately for each Pin 
int val1;
int val2;
int val3;


// brightness value for fadeToOn
int i = 255;    

// brightness values for blink
int j = 0;    
int k= 255;


// for producing the delay
long previousMillis = 0;        // will store the value last time LED was updated
long interval = 40;           // the interval of blinking (milliseconds)





/////////////////////////////////////////// SETUP ////////////////////////////////////////////
void setup()
{
  Serial.begin(9600);
  pinMode(ledpin1, OUTPUT);
  pinMode(ledpin2, OUTPUT);
  pinMode(ledpin3, OUTPUT);
}


/////////////////////////////////////////// LOOP ////////////////////////////////////////////
void loop()
{

  if (Serial.available()){
    val = Serial.read();

    // ledPin1    
    if (val == 'r'){       
      fadeToOn(ledpin1); 
      val1 =val; 
    }
    if (val == 'f'){  
      blink(ledpin1);      
      val1 =val; 
    }
    if  (val == 'v'){ 
      turnOff(ledpin1);
      val1 =val; 
    }

    // ledPin2  
    if (val == 't'){       
      fadeToOn(ledpin2);  
      val2 =val; 
    }
    if (val == 'g'){  
      blink(ledpin2); 
      val2 =val;      
    }
    if  (val == 'b'){ 
      turnOff(ledpin2);
      val2 =val; 
    }


    // ledPin3  
    if (val == 'y'){       
      fadeToOn(ledpin3);  
      val3 =val; 
    }
    if (val == 'h'){  
      blink(ledpin3); 
      val3 =val;      
    }
    if  (val == 'n'){ 
      turnOff(ledpin3);
      val3 =val; 
    }

  }

  if (val1 == 'f'){  
    blink(ledpin1); 
  }
  if (val2 == 'g'){  
    blink(ledpin2); 
  }
  if (val3 == 'h'){  
    blink(ledpin3); 
  }


}



///////////////////////////////////// function: fade to on ///////////////////////////////////////
void fadeToOn(int ledpin){
  while(j<255){
    if ((millis() - previousMillis) > interval) {
      analogWrite(ledpin, j);  // sets the value (range from 0 to 255)
      j+=5;
      previousMillis = millis();
    }
  }
  if (j=255){
    analogWrite(ledpin,255);
  }
  j=0;

}

///////////////////////////////////// function: blink with fade  ///////////////////////////////////////
void blink(int ledpin){

  while(i<25){    //fade to on
    if ((millis() - previousMillis) > interval) {
      analogWrite(ledpin, i);  // sets the value (range from 0 to 255)
      i+=5;
      previousMillis = millis();
    }  
  }

  while(i>=25 && i<255){  
    if ((millis() - previousMillis) > interval) {
      analogWrite(ledpin, i);  // sets the value (range from 0 to 255)
      i+=5;
      previousMillis = millis();
    }  
  }
  i=25;

  while(k>25){
    if ((millis() - previousMillis) > interval) {
      analogWrite(ledpin, k);  // sets the value (range from 0 to 255)
      k-=5;
      previousMillis = millis();
    }
  }
  k=255;
}

///////////////////////////////////// function:  turn off the led  ///////////////////////////////////////
void turnOff(int ledpin){
  analogWrite (ledpin, 0);
}