#include <DigiJoystick.h>

//Vcc5v-紫(6) G-茶(8)もつなぐ()は互換機のピン
#define CLOCK 2 //青(4)
#define LATCH 1 //黄(3)
#define DATA  0 //緑(2)

#define CENTER 127

uint8_t joyData[8];
byte padStatus;
byte padOldStatus;

void setup()
{
  pinMode(LATCH, OUTPUT);
  pinMode(CLOCK, OUTPUT);
  pinMode(DATA, INPUT);

  padOldStatus = 0;
  padStatus = 0xff;
}

void loop() {
  padStatus = readData();
  if(padStatus != padOldStatus)
  {
    joyData[0] = CENTER;
    joyData[1] = CENTER;
    if(!bitRead(padStatus,4)) joyData[1] = 0; //上
    else if(!bitRead(padStatus,5)) joyData[1] = 255; //下
    if(!bitRead(padStatus,6)) joyData[0] = 0; //左
    else if(!bitRead(padStatus,7)) joyData[0] = 255; //右
    joyData[6] = ~padStatus & 0xf; //ボタン
    padOldStatus = padStatus;
    //ジョイスティックの値をセット
    DigiJoystick.setValues(joyData);
  }
  DigiJoystick.delay(50);
}

byte readData()
{
  byte data;
  
  digitalWrite(LATCH, LOW);
  digitalWrite(CLOCK, LOW);
  digitalWrite(LATCH, HIGH);
  delayMicroseconds(12);
  digitalWrite(LATCH, LOW);
 
  for(int i=0; i<8; i++)
  {
    bitWrite(data, i, digitalRead(DATA));
    digitalWrite(CLOCK, HIGH);
    delayMicroseconds(12);
    digitalWrite(CLOCK, LOW);
    delayMicroseconds(12);
  }

  return data;
}