FYP2 WEEK 9

 Activity: Complete the coding for FYP 2

Objective: 

• To complete the DHT22 coding for the project
• To test the coding and troubleshoot the program if there is any problem

#include <Wire.h>

#include "DHT.h"

#include <LiquidCrystal_I2C.h>

#define DHTPIN 12

#define DHTTYPE DHT22

LiquidCrystal_I2C lcd (0x27, 20, 4);      //I2C address 0x27, 20 column and 4 row

DHT dht(DHTPIN,DHTTYPE);

int temp_sensor_pin = A0;                 //The output pin of LM35

int ref_pin = A1;

int fan_pin = 9;

int waterpump_pin = 10; 

int heater_pin = 5;

int red_led = 6;

int green_led = 7;

int blue_led = 8;

int buzzer_pin = 11;

int fan_speed;

int ref_value_min = 0;

int ref_value_max = 50;

int max_temp_limit;

int min_temp_limit;

void setup ()

{

  Serial.begin(9600);

  dht.begin();

  lcd.init();

  lcd.backlight();

  lcd.setCursor(6,0);

  lcd.print("AUTOMATIC");

  lcd.setCursor(0,1);

  lcd.print("COOLING ROOF SYSTEM");

  lcd.setCursor(10,2);

  lcd.print("BY");

  lcd.setCursor(8,3);

  lcd.print("EIZLAN");

  delay(1500);

  lcd.clear();

  lcd.setCursor(0,0);

  lcd.print("Ref.Temp:");

  lcd.setCursor(0,1);

  lcd.print("Cur.Temp:");

  pinMode(red_led,OUTPUT);

  pinMode(green_led,OUTPUT);

  pinMode(blue_led,OUTPUT);

  analogWrite(fan_pin, fan_speed);

  analogWrite(waterpump_pin, fan_speed);

}

void loop()

{

  int ref_value;

  float temperature = dht.readTemperature();

  ref_value = analogRead(ref_pin);

  ref_value = map(ref_value, 0, 1023, 0, 100);

  max_temp_limit = ref_value+5;

  min_temp_limit = ref_value-5;

  lcd.setCursor(10,0);

  lcd.print(ref_value);                             //Print refference temperature

  lcd.print(" ");

  lcd.print((char)223);   

  lcd.print("C");

  lcd.setCursor(10,1);

  lcd.print(temperature);                           //Print temperature

  lcd.print(" ");

  lcd.print((char)223);

  lcd.print("C");

  Serial.print("Temperature: ");

  Serial.println(temperature);

  if (temperature > max_temp_limit)

  {

    lcd.setCursor(0,2);

    lcd.print("HIGH TEMPERATURE");

    lcd.setCursor(0,3);

    lcd.print("FAN & WP TURN ON");

    if(fan_speed<150) fan_speed +=20;

    analogWrite(fan_pin, fan_speed);

    analogWrite(waterpump_pin, fan_speed);

    digitalWrite(heater_pin, LOW);

    digitalWrite(red_led,HIGH);

    delay(100);

    digitalWrite(red_led,LOW);

    digitalWrite(green_led,LOW);

    digitalWrite(blue_led,LOW);

    tone(buzzer_pin,1245,1000);

  }

  else if (temperature < min_temp_limit)

  {

    lcd.clear();

    lcd.setCursor(0,0);

    lcd.print("Ref.Temp:");

    lcd.setCursor(0,1);

    lcd.print("Cur.Temp:");

    lcd.setCursor(10,0);

    lcd.print(ref_value);                             //Print refference temperature

    lcd.print(" ");

    lcd.print((char)223);   

    lcd.print("C");

    lcd.setCursor(10,1);

    lcd.print(temperature);                           //Print temperature

    lcd.print(" ");

    lcd.print((char)223);

    lcd.print("C");

    lcd.setCursor(0,2);

    lcd.print("LOW TEMPERATURE");

    lcd.setCursor(0,3);

    lcd.print("HEATER TURN ON");

   if(fan_speed<150) fan_speed +=20;

    digitalWrite(fan_pin, LOW);

    digitalWrite(waterpump_pin, LOW);

    analogWrite(heater_pin, fan_speed);

    digitalWrite(red_led,LOW);

    digitalWrite(green_led,LOW);

    digitalWrite(blue_led,HIGH);

  }

  else if((temperature <max_temp_limit) && (temperature > min_temp_limit))

  {

    lcd.clear();

    lcd.setCursor(0,0);

    lcd.print("Ref.Temp:");

    lcd.setCursor(0,1);

    lcd.print("Cur.Temp:");

    lcd.setCursor(10,0);

    lcd.print(ref_value);                             //Print refference temperature

    lcd.print(" ");

    lcd.print((char)223);   

    lcd.print("C");

    lcd.setCursor(10,1);

    lcd.print(temperature);                           //Print temperature

    lcd.print(" ");

    lcd.print((char)223);

    lcd.print("C");

    lcd.setCursor(0,2);

    lcd.print("TEMPERATURE IS");

    lcd.setCursor(0,3);

    lcd.print("WITHIN LIMIT");

    

    if(fan_speed<150) fan_speed +=20;

    analogWrite(fan_pin, fan_speed); 

    digitalWrite(waterpump_pin, LOW);

    digitalWrite(heater_pin, LOW);

    digitalWrite(red_led,LOW);

    digitalWrite(green_led,HIGH);

    digitalWrite(blue_led,LOW);

    }

  delay(1000);                            //1s delay 

}