// Kode 3.4 : Pengukuran Periode dengan Interupsi

#define PERIODE_DISPLAY 5
#define PERIODE_GATE 100

#define NPulse 10

// Pemetaan Port
#define BUTTON1 A2
#define OPTO 2
#define BCD1 8
#define T1 12
#define T2 13
#define MOTOR_INPUT1 3
#define MOTOR_INPUT2 A1

// fungsi-fungsi dari modul sebelumnya
boolean s1IsPressed() {
  static boolean b1_old = 0;
  boolean b1 = digitalRead (BUTTON1);
  boolean s1 = (b1 && !b1_old);
  b1_old = b1;
  return s1;
}

void writeDigit(int bcd){
  for (int i=0; i<4; i++){
    digitalWrite(BCD1 + i, bcd & 0x01);
    bcd = bcd >> 1;
  }
}

int digits[3];
void writeDigit3(int data) {
  digits[0] = data%10;
  data = data/10;
  digits[1] = data % 10;
  data = data / 10;
  digits[2] = data %10;
}

int index = 0;
void shiftDigit() {
  writeDigit(digits[index]);
  digitalWrite(T1, index & 0x02);
  digitalWrite(T2, index & 0x01);
  index = (index + 1) % 3;
}

// memeriksa ada tidaknya pulsa pada optocoupler
boolean optoIsFired() {
  static boolean b1_old = 1;
  boolean b1 = digitalRead(OPTO);
  boolean s1 = (b1 && !b1_old);
  b1_old = b1;
  return s1;
}
//variabel global
long tdisplay, tgate;
volatile long pulse;
int pwm;

void setup() {
  Serial.begin(115200);
  Serial.println("Pengukuran Periode dengan Interupsi");
  // inisialisasi mode pin
    for(int pin=BCD1;pin<=T2;pin++){
      pinMode(pin, OUTPUT);
    }
  attachInterrupt(digitalPinToInterrupt(OPTO),taskOpto,RISING);

  // Inisialisasi shift register
  pinMode(T1, OUTPUT);
  pinMode(T2, OUTPUT);
  digitalWrite(T1,LOW);
  digitalWrite(T2,LOW);

  // Inisialisasi INPUT1 dan INPUT2 motor driver
  pinMode(MOTOR_INPUT1, OUTPUT);
  pinMode(MOTOR_INPUT2, OUTPUT);
  analogWrite(MOTOR_INPUT1, 0);
  digitalWrite(MOTOR_INPUT2, LOW);

  // Inisialisasi BUTTON1
  pinMode(BUTTON1, INPUT);
  digitalWrite(BUTTON1,HIGH);

  // inisialisasi variabel global
  tgate = tdisplay = millis();
  pulse = 0;
  pwm = 255;
}

// Menurunkan pwm secara step
void taskButton() {
  pwm = pwm - (256/16);
  if (pwm < 0) pwm = 255;
  analogWrite(MOTOR_INPUT1, pwm);
}

// Menaikkan cacahan pulse apabila opto terdeteksi
void taskOpto() {
  pulse++;
}

// Task dipanggil setiap Tgate
// untuk menghitung Period
void taskPeriod(long ms) {

  long tgate2 = ms;
  long tw = tgate2-tgate;

  // hitung period
  float period = float(tw)/NPulse;

  // tampilkan ke 7 segment
  writeDigit3(period);

  // untuk membandingkan, kirim ke serial
  // pwm tw pulse periodd
  Serial.print(pwm);
  Serial.print(" ");
  Serial.print(tw);
  Serial.print(" ");
  Serial.print(pulse);
  Serial.print(" ");
  Serial.println(period);

  // reset cacahan
  pulse = 0;
  tgate=millis();
}

// task menampilkan bacaan 7 segment
void taskDisplay() {
  shiftDigit();
}

// loop utama
void loop() {
  long ms = millis();
  if (optoIsFired()) {
    taskOpto();
  }
  else if (pulse >= NPulse) {
    noInterrupts();
    taskPeriod(ms);
    tgate = millis();
    interrupts();
  }
  else if (s1IsPressed()) {
    noInterrupts();
    taskButton();
    interrupts();
  }
  else if (ms >= tdisplay) {
    taskDisplay();
    tdisplay = tdisplay + PERIODE_DISPLAY;
  }
}