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

#define TEMP_ONE 7
#define TEMP_TWO 8

OneWire oneWireOne(TEMP_ONE);
OneWire oneWireTwo(TEMP_TWO);

DallasTemperature sensorsOne(&oneWireOne);
DallasTemperature sensorsTwo(&oneWireTwo);

float zeroPoint = 0;         // Variable to store the zero point temperature
float lastCelsiusTwo = 0;    // Variable to store the last temperature of sensor two

void setup() {
  sensorsOne.begin();
  sensorsTwo.begin();
  Serial.begin(9600);
  setZeroPoint();  // Set the initial zero point
  sensorsTwo.requestTemperatures();
  lastCelsiusTwo = sensorsTwo.getTempCByIndex(0);  // Initialize the last temperature
}

void loop() {
  sensorsOne.requestTemperatures();
  sensorsTwo.requestTemperatures();

  float CelsiusOne = sensorsOne.getTempCByIndex(0);
  float CelsiusTwo = sensorsTwo.getTempCByIndex(0);

  // Calculate the temperature difference with sensor one as the main temperature
  float tempDifferenceC = CelsiusTwo - zeroPoint;

  // Check if the temperature difference is negative
  if (tempDifferenceC < 0) {
    setZeroPoint();       // Reset the zero point
    tempDifferenceC = 0;  // Reset the temperature difference
    Serial.println("Zero point readjusted due to negative difference.");
  }

  // Print the temperature difference
  Serial.print("Temperature Difference from Sensor One: ");
  Serial.print(tempDifferenceC);
  Serial.println(" C");

  float tempRate = (CelsiusTwo - lastCelsiusTwo);  // Temperature change rate in °C/s

  if (abs(tempRate) >= 0.5) {
    Serial.print("Sudden Temperature Change Detected: ");
    Serial.print(tempRate);
    Serial.println(" °C/s");
  }

  // Update the last temperature and time
  lastCelsiusTwo = CelsiusTwo;
}

// Function to set the zero point
void setZeroPoint() {
  sensorsOne.requestTemperatures();
  zeroPoint = sensorsOne.getTempCByIndex(0);
}