/*
 * This ESP32 code is created by esp32io.com
 *
 * This ESP32 code is released in the public domain
 *
 * For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-cooling-system-using-ds18b20-temperature-sensor
 */

 //Modified by Kishore Gaikwad, 23-Apr-2022

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

#define TEMP_UPPER_THRESHOLD  36 // upper temperature threshold
//#define TEMP_LOWER_THRESHOLD  34 // lower temperature threshold

#define SENSOR_PIN     12  // ESP32 pin connected to DS18B20 sensor's DQ pin
#define RELAY_FAN_PIN  26 // ESP32 pin connected to relay

OneWire oneWire(SENSOR_PIN);
DallasTemperature DS18B20(&oneWire);

void setup() {
  Serial.begin(115200); // initialize serial
  DS18B20.begin();    // initialize the DS18B20 sensor
  pinMode(RELAY_FAN_PIN, OUTPUT);
}

void loop() {
  DS18B20.requestTemperatures();                  // send the command to get temperatures
  float temperature = DS18B20.getTempCByIndex(0); // read temperature in Celsius
  Serial.print(temperature);
  Serial.println("ºC");
  if (temperature > TEMP_UPPER_THRESHOLD) {
    Serial.println("Turn the fan on");
    digitalWrite(RELAY_FAN_PIN, LOW); // turn on
  } else if (temperature < TEMP_UPPER_THRESHOLD) {
    Serial.println("Turn the fan off");
    digitalWrite(RELAY_FAN_PIN, HIGH); // turn off
  }

  delay(500);
}