#include <Servo.h>

// =======================
// Konfigurasi Pin
// =======================
const int o2Pin = A9;      // Input sensor O₂ (potensiometer)
const int rpmPin = A8;     // Input simulasi RPM (potensiometer)
const int servoPin = 7;    // Output servo

// =======================
// Konfigurasi Batas RPM
// =======================
int maxRPM = 9000;  // Bisa diganti menjadi 8500, 12000, dll.

// =======================
// Objek Servo
// =======================
Servo limiterServo;

// =======================
// Variabel Global
// =======================
float o2Voltage = 0;
int o2Value = 0;
int rpmValue = 0;
int rpm = 0;
int servoAngle = 0;
String mixtureStatus;

void setup() {
  Serial.begin(9600);
  limiterServo.attach(servoPin);

  Serial.println("=== ECU SIMULATOR START ===");
  delay(800);
}

void loop() {

  // =======================
  // BACA SENSOR O₂
  // =======================
  o2Value = analogRead(o2Pin);
  o2Voltage = o2Value * (5.0 / 1023.0);

  if (o2Voltage < 0.3) mixtureStatus = "LEAN";
  else if (o2Voltage <= 0.7) mixtureStatus = "IDEAL";
  else mixtureStatus = "RICH";

  // =======================
  // BACA PULSER (SIMULASI RPM)
  // =======================
  rpmValue = analogRead(rpmPin);
  rpm = map(rpmValue, 0, 1023, 0, maxRPM);

  // =======================
  // SERVO FULL 0–180 BASED ON RPM
  // =======================
  servoAngle = map(rpm, 0, maxRPM, 0, 180);

  // Batasi jika lewat batas (jaga servo aman)
  servoAngle = constrain(servoAngle, 0, 180);

  limiterServo.write(servoAngle);

  // =======================
  // OUTPUT SERIAL MONITOR
  // =======================
  Serial.print("RPM: ");
  Serial.print(rpm);

  Serial.print(" | O2: ");
  Serial.print(o2Voltage, 2);
  Serial.print("V");

  Serial.print(" | Mixture: ");
  Serial.print(mixtureStatus);

  Serial.print(" | Servo: ");
  Serial.print(servoAngle);
  Serial.println(" deg");

  delay(250);
}