// (Really Simple) PID Class by Ivan Seidel
// GitHub.com/ivanseidel
// Use as you want. Leave credits

class PID{
public:

	double error;
	double sample;
	double lastSample;
	double kP, kI, kD;
	double P, I, D;
	double pid;

	double setPoint;
	long lastProcess;

	PID(double _kP, double _kI, double _kD){
		kP = _kP;
		kI = _kI;
		kD = _kD;
	}

	void addNewSample(double _sample){
		sample = _sample;
	}

	void setSetPoint(double _setPoint){
		setPoint = _setPoint;
	}

	double process(){
		// Implementação P ID
		error = setPoint - sample;
		float deltaTime = (millis() - lastProcess) / 1000; ;
		lastProcess = millis();

		//P
		P = error * kP;

		//I
		I = I + (error * kI) * (deltaTime/1000);

		//D
		D = (lastSample - sample) * kD / deltaTime;
		lastSample = sample;

		// Soma tudo
		pid = P + I + D;

		return pid;
	}
};

#define pSENSOR         A1
#define pCONTROLE       3

PID meuPid(1.0, 0, 0);

void setup() {
	Serial.begin(9600);

	pinMode(pSENSOR, INPUT);
	pinMode(pCONTROLE, OUTPUT);
}

int controlePwm = 50;

void loop() {

	// Lê temperatura
	double temperature = map(analogRead(pSENSOR), 0, 1023, 0, 100);

	// Manda pro objeto PID!
	meuPid.addNewSample(temperature);


	// Converte para controle
	controlePwm = (meuPid.process() + 50);
	// Saída do controle
	analogWrite(pCONTROLE, controlePwm);

}