/*
Controlling LEDs via NES Controller
Created/Modified By Edward Ford
19 February 2010
Dixon, IL

Original Work:
Reading a NES Controller
By Sebastian Tomczak
21 July 2007
Adelaide, Australia
*/

int latch = 2; // set the latch pin
int clock = 3; // set the clock pin
int datin = 4;// set the data in pin

int upPin = 12; //set direction UP arrow to Pin 12
int downPin = 11; //set direction DOWN arrow to Pin 11
int leftPin = 10; //set direction LEFT arrow to Pin 10
int rightPin = 9; //set direction RIGHT arrow to Pin 9

int selectPin = 8; //set button SELECT arrow to Pin 8
int startPin = 7; //set button START arrow to Pin 7

int bPin = 6; //set button b to Pin 6
int aPin = 5; //set button a to Pin 5
byte controller_data = 0;

/* SETUP */
void setup() {
  Serial.begin(57600);
  pinMode(latch,OUTPUT);
  pinMode(clock,OUTPUT);
  pinMode(datin,INPUT);
  
  pinMode(upPin, OUTPUT);
  pinMode(downPin, OUTPUT);
  pinMode(leftPin, OUTPUT);
  pinMode(rightPin, OUTPUT);
  pinMode(selectPin, OUTPUT);
  pinMode(startPin, OUTPUT);
  pinMode(bPin, OUTPUT);
  pinMode(aPin, OUTPUT);
  
  digitalWrite(latch,HIGH);
  digitalWrite(clock,HIGH);
}

/* CONTROLLER READ */
void controllerRead() {
  controller_data = 0;
  digitalWrite(latch,LOW);
  digitalWrite(clock,LOW);

  digitalWrite(latch,HIGH);
  delayMicroseconds(2);
  digitalWrite(latch,LOW);

  controller_data = digitalRead(datin);

  for (int i = 1; i <= 7; i ++) {
    digitalWrite(clock,HIGH);
    delayMicroseconds(2);
    controller_data = controller_data << 1;
    controller_data = controller_data + digitalRead(datin) ;
    delayMicroseconds(4);
    digitalWrite(clock,LOW);
  }
}

/* PROGRAM */
void loop() {
controllerRead();
 /*This is where all the action is. Loop calls the controllerRead function which 
 controllerRead then returns a number in binary form. If the no buttons are pressed
 then controllerRead returns 11111111. See comments below for specific return values
 
 The switch statement then reads controller_data and compares it the the 8 known values it may produce.
 Those conditions are then mapped to an LED which is defined in the top section of the code.
 */
 switch (controller_data) {
   case B01111111:    // A = 01111111
     digitalWrite(aPin, HIGH); //turn A LED on
     break;
   case B10111111:    // B = 10111111
     digitalWrite(bPin, HIGH);
     break;
   case B11011111:    // Select Button = 11011111
     digitalWrite(selectPin, HIGH);
     break;
   case B11101111:    // Start = 11101111
     digitalWrite(startPin, HIGH); //turn STRART LED on
     break;
   case B11110111:    // UP = 11110111
     digitalWrite(upPin, HIGH); //turn UP LED on
     break;
   case B11111011:    // DOWN = 11111011
     digitalWrite(downPin, HIGH); //turn DOWN LED on
     break;
   case B11111101:    // LEFT = 11111101
     digitalWrite(leftPin, HIGH); //turn LEFT LED on
     break;
   case B11111110:    // RIGHT = 11111110
     digitalWrite(rightPin, HIGH); //turn RIGHT LED on
     break;
 }
   delay(10);
   //return all pins to LOW.
     digitalWrite(upPin, LOW);
     digitalWrite(downPin, LOW);
     digitalWrite(leftPin, LOW);
     digitalWrite(rightPin, LOW);
     digitalWrite(selectPin, LOW);
     digitalWrite(startPin, LOW);
     digitalWrite(bPin, LOW);
     digitalWrite(aPin, LOW);
   //Wait for next button push
}