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

bit 7 = A
bit 6 = B
bit 5 = select
bit 4 = start
bit 3 = up
bit 2 = down
bit 1 = left
bit 0 = right
*/

/* INITIALISATION */

int latch = 2; // set the latch pin
int clock = 3; // set the clock pin
int datin = 4;// set the data in pin
byte controller_data = 0;

/* SETUP */
void setup() {
Serial.begin(57600);
pinMode(latch,OUTPUT);
pinMode(clock,OUTPUT);
pinMode(datin,INPUT);

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();
Serial.println(controller_data, BIN);
delay(100);
}