#include <OneWire.h>
#include <DallasTemperature.h>

#define ONE_WIRE_BUS 2

#define GREEN_LED 5
#define YELLOW_LED 6
#define RED_LED 7
#define BUZZER 8

OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);

float currentTemp;
float previousTemp = -100;
float maxTemp = -100;

void setup() {

  Serial.begin(9600);

  sensors.begin();

  pinMode(GREEN_LED, OUTPUT);
  pinMode(YELLOW_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(BUZZER, OUTPUT);

  Serial.println("=================================");
  Serial.println(" SMART TEMPERATURE MONITOR PRO");
  Serial.println("=================================");
}

void loop() {

  sensors.requestTemperatures();

  currentTemp = sensors.getTempCByIndex(0);

  if (currentTemp == DEVICE_DISCONNECTED_C) {
    Serial.println("Sensor Error!");
    delay(1000);
    return;
  }

  if (currentTemp > maxTemp)
    maxTemp = currentTemp;

  Serial.print("Current Temperature : ");
  Serial.print(currentTemp);
  Serial.println(" C");

  Serial.print("Maximum Temperature : ");
  Serial.print(maxTemp);
  Serial.println(" C");

  if (previousTemp != -100) {

    if (currentTemp > previousTemp)
      Serial.println("Trend : Rising");

    else if (currentTemp < previousTemp)
      Serial.println("Trend : Falling");

    else
      Serial.println("Trend : Stable");

  }

  if (currentTemp < 25) {

    Serial.println("Status : SAFE");

    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(YELLOW_LED, LOW);
    digitalWrite(RED_LED, LOW);

    noTone(BUZZER);

  }

  else if (currentTemp < 35) {

    Serial.println("Status : WARNING");

    digitalWrite(GREEN_LED, LOW);
    digitalWrite(YELLOW_LED, HIGH);
    digitalWrite(RED_LED, LOW);

    noTone(BUZZER);

  }

  else {

    Serial.println("Status : DANGER");

    digitalWrite(GREEN_LED, LOW);
    digitalWrite(YELLOW_LED, LOW);
    digitalWrite(RED_LED, HIGH);

    tone(BUZZER,1000);

  }

  previousTemp = currentTemp;

  Serial.println("----------------------------");

  delay(1000);
}