#include <Adafruit_Sensor.h>
#include <OneWire.h>      // For DS18B20 sensor
#include <DallasTemperature.h>
#include <Wire.h>


#define TEMP_THRESHOLD 30     //temperature threshold in Celsius

#define DS18B20_PIN 4         // DS18B20 sensor pin (liquid temperature)
#define HEATER_PIN 14         // Heater control pin
#define PELTIER_PIN 27        // Peltier module control pin


float liquidTemperature = 0.0; // Liquid temperature from DS18B20

// Setup for DS18B20
OneWire oneWire(DS18B20_PIN);
DallasTemperature sensors(&oneWire);

void setup() {
  Serial.begin(9600);
  
  
  // Initialize output devices
  pinMode(HEATER_PIN, OUTPUT);
  pinMode(PELTIER_PIN, OUTPUT);

  // Turn off all output devices initially
  digitalWrite(HEATER_PIN, LOW);
  digitalWrite(PELTIER_PIN, LOW);
}

void loop() {
// Read liquid temperature from DS18B20
  sensors.requestTemperatures();
  liquidTemperature = sensors.getTempCByIndex(0); // Assuming one DS18B20 sensor

  // Print sensor readings
  Serial.print("Liquid Temperature: "); Serial.print(liquidTemperature); Serial.println(" C");
  // Control logic for output devices
  controlHeater();
  controlPeltier();
  
  delay(2000); // Adjust delay as per required sampling rate
}
// Function to read level sensor using HC-SR04

void controlHeater() {
  if (liquidTemperature < TEMP_THRESHOLD) {
    digitalWrite(HEATER_PIN, HIGH); // Turn on heater if temperature is below threshold
    Serial.println("Heater ON");
  } else {
    digitalWrite(HEATER_PIN, LOW); // Turn off heater
    Serial.println("Heater OFF");
  }
}

void controlPeltier() {
  if (liquidTemperature > TEMP_THRESHOLD) {
    digitalWrite(PELTIER_PIN, HIGH); // Cool down if temperature exceeds threshold
    Serial.println("Peltier ON (Cooling)");
  } else {
    digitalWrite(PELTIER_PIN, LOW);
    Serial.println("Peltier OFF");
  }
}