// Author:  Nien Lam
// Date:    09-15-2009
// Title:   Finger Switches
// Descr:   Metal contacts attached to the fingers (index, middle, ring) when touched with 
//          a metal plate will light the corresponding LED.  When all 3 fingers close the 
//          switch, the larger LED turns on.


// Digital input pins for finger swtiches.
int indexFinPin  = 2;
int middleFinPin = 3;
int ringFinPin   = 4;

// Digital output pins for the LEDs.
int firstLedPin  = 8;
int secondLedPin = 9;
int thirdLedPin  = 10;
int masterLedPin = 11;


void setup() 
{
  // Set finger switches as inputs.
  pinMode(indexFinPin,  INPUT);      
  pinMode(middleFinPin, INPUT);      
  pinMode(ringFinPin,   INPUT);      

  // Set LEDs as output.
  pinMode(firstLedPin,  OUTPUT);      
  pinMode(secondLedPin, OUTPUT);      
  pinMode(thirdLedPin,  OUTPUT);     
  pinMode(masterLedPin, OUTPUT);     
}


void loop() 
{
  // Reset all LEDs to LOW state.
  digitalWrite(firstLedPin,  LOW);    
  digitalWrite(secondLedPin, LOW);    
  digitalWrite(thirdLedPin,  LOW);    
  digitalWrite(masterLedPin,  LOW);    


  // Turn on LEDs depending on which finger switch is closed.
  if (digitalRead(indexFinPin))
    digitalWrite(firstLedPin, HIGH);    

  if (digitalRead(middleFinPin))
    digitalWrite(secondLedPin, HIGH);    

  if (digitalRead(ringFinPin))
    digitalWrite(thirdLedPin, HIGH);    


  // Turn on Master LED if all finger switches are closed.
  if (digitalRead(indexFinPin) && digitalRead(middleFinPin) && digitalRead(ringFinPin))
    digitalWrite(masterLedPin, HIGH);    


  // Add delay for each cycle.
  delay(200);
}