#include <Arduino.h>

#include <DHT.h> // Library for the DHT sensor

#include <PID_v1.h> // Library for the PID controller

#define DHT_PIN 2 // Pin number for the DHT sensor

#define HEATER_PIN 14 // Pin number for the heater

#define DHT_TYPE DHT11 // Type of DHT sensor (DHT11, DHT22, etc.)

// Parameters for the PID controller

#define Kp 1

#define Ki 0.1

#define Kd 0.1

#define SAMPLE_TIME 1000 // Sample time in milliseconds

// Setpoint for the temperature (in degrees Celsius)

#define TEMPERATURE_SETPOINT 25

// Variables for the PID controller

double input = 0;

double output = 0;

double setpoint = TEMPERATURE_SETPOINT;

PID pid(&input, &output, &setpoint, Kp, Ki, Kd, REVERSE);

DHT dht(DHT_PIN, DHT_TYPE); // Initialize the DHT sensor

void setup() {

// put your setup code here, to run once:

Serial.begin(115200);

dht.begin();

pid.SetSampleTime(SAMPLE_TIME); // Set the sample time for the PID controller

pinMode(HEATER_PIN, OUTPUT); // Set the heater pin as an output

pid.SetMode(AUTOMATIC); // Enable the PID controller

}

void loop() {

// put your main code here, to run repeatedly:

// Read the temperature and humidity from the DHT sensor

float temperature = dht.readTemperature();

float humidity = dht.readHumidity();

// Set the input value for the PID controller

input = temperature;

// Compute the output value from the PID controller

pid.Compute();

// Set the output value as the duty cycle of the heater

analogWrite(HEATER_PIN, output);

// Print the temperature and humidity to the serial console

Serial.print("Temperature: ");

Serial.print(temperature);

Serial.print("C, Humidity: ");

Serial.print(humidity);

Serial.println("%");

// Delay for the sample time

delay(SAMPLE_TIME);

}