#include <Adafruit_Sensor.h>

#include <DHT.h>

#include <DHT_U.h>

#define DHTPIN 5 // Digital pin connected to the DHT sensor

#define DHTTYPE DHT11 // DHT 11

DHT_Unified dht(DHTPIN, DHTTYPE);

uint32_t delayMS;

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20,4); // set the LCD address to 0x27 for a 16 chars and 2 line display

int Selector = 2;

int Switch = 3;

int relay = 4;

int LEDRed = 8;

int LEDWhite = 9;

void setup()

{

pinMode (relay, OUTPUT);

pinMode (Switch, INPUT_PULLUP);

pinMode (Selector, INPUT);

pinMode (LEDRed, OUTPUT);

pinMode (LEDWhite, OUTPUT);

Serial.begin(9600);

// Initialize device.

dht.begin();

Serial.println(F("DHTxx Unified Sensor Example"));

// Print temperature sensor details.

sensor_t sensor;

dht.temperature().getSensor(&sensor);

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

Serial.println(F("Temperature Sensor"));

Serial.print (F("Sensor Type: ")); Serial.println(sensor.name);

Serial.print (F("Driver Ver: ")); Serial.println(sensor.version);

Serial.print (F("Unique ID: ")); Serial.println(sensor.sensor_id);

Serial.print (F("Max Value: ")); Serial.print(sensor.max_value); Serial.println(F("°C"));

Serial.print (F("Min Value: ")); Serial.print(sensor.min_value); Serial.println(F("°C"));

Serial.print (F("Resolution: ")); Serial.print(sensor.resolution); Serial.println(F("°C"));

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

// Print humidity sensor details.

dht.humidity().getSensor(&sensor);

Serial.println(F("Humidity Sensor"));

Serial.print (F("Sensor Type: ")); Serial.println(sensor.name);

Serial.print (F("Driver Ver: ")); Serial.println(sensor.version);

Serial.print (F("Unique ID: ")); Serial.println(sensor.sensor_id);

Serial.print (F("Max Value: ")); Serial.print(sensor.max_value); Serial.println(F("%"));

Serial.print (F("Min Value: ")); Serial.print(sensor.min_value); Serial.println(F("%"));

Serial.print (F("Resolution: ")); Serial.print(sensor.resolution); Serial.println(F("%"));

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

// Set delay between sensor readings based on sensor details.

delayMS = sensor.min_delay / 1000;

lcd.init();

lcd.backlight();

}

void loop()

{

delay(delayMS);

sensors_event_t event;

dht.temperature().getEvent(&event);

if (isnan(event.temperature)) {

Serial.println(F("Error reading temperature!"));

}

else {

Serial.print(F("Temperature: "));

Serial.print(event.temperature);

Serial.println(F("°C"));

}

dht.humidity().getEvent(&event);

if (isnan(event.relative_humidity)) {

Serial.println(F("Error reading humidity!"));

}

else {

Serial.print(F("Humidity: "));

Serial.print(event.relative_humidity);

Serial.println(F("%"));

}

if (digitalRead (Selector) == LOW)

{

if (digitalRead (Switch) == HIGH)

{

lcd.setCursor(1, 0);

lcd.print("Manual Mode");

lcd.setCursor(3, 1);

lcd.print("Active Fan");

digitalWrite (relay, HIGH);

digitalWrite (LEDRed, HIGH);

digitalWrite (LEDWhite, LOW);

Serial.println("Active fan");

}

else

{

lcd.setCursor(1, 0);

lcd.print("Manual Mode");

lcd.setCursor(2, 1);

lcd.print("Disactive Fan");

digitalWrite (relay, LOW);

digitalWrite (LEDRed, LOW);

digitalWrite (LEDWhite, LOW);

Serial.println("Disactive Fan");

}

}

else {

if (event.temperature > 30) // read event.temperature

{

lcd.setCursor(0, 0);

lcd.print("Automatic Mode");

lcd.setCursor(2, 1);

lcd.print("The fan is on");

lcd.setCursor(2, 0);

Serial.println("The fan is turned on");

digitalWrite(relay, HIGH); // turn on

digitalWrite (LEDRed, LOW);

digitalWrite (LEDWhite, HIGH);

}

else {

digitalWrite(relay, LOW); // turn off

digitalWrite (LEDRed, LOW);

digitalWrite (LEDWhite, LOW);

Serial.println("The fan is Off");

lcd.setCursor(0, 0);

lcd.print("Automatic Mode");

lcd.setCursor(2, 1);

lcd.print("The fan is off");

lcd.setCursor(2, 0);

}

}

}

In the next auto mode animation video the yellow DC fan motor was shown because the Dc fan is suddenly became not working, so I had to use an alternative for the DC fan only, while everything works in the text code as programmed as the LCD writes in time A text message indicates the fan is on/off and there is a white LED inside the enclosure emitting light in the fan's working mode and vice versa. I should not forget to mention that according to the DHT11 sensor in the video it measures the temperature and humidity and takes action based on it and this is the function of the auto mode.

This exercise basically relies on 4 LEDs to switch ON and then OFF sequentially in one direction from right to left (the first LED will turn on, then turn off at the same moment the second LED is on, then turn off at the same time the moment That the third LED is on … and so on).

Whenever I press the pushbutton, the illumination order of the 4 LEDs will be reversed in the direction. Also, turning the potentiometer knob changes the speed of switching LEDs; either faster or slower

The components used were as follows:

• 1 Arduino UNO

• 4 LEDs

• 1 Push Button

• 1 Potentiometer

• 1 Breadboard

• Jumper wires

The idea of the lock system is to make connections via wires and using a servo motor (180) and a keypad to simulate the process of opening a safe protected with a secret number.

The idea of the lock system is to make connections via wires and use a servomotor (180) and a keypad to simulate the process of opening a safe protected by a password.

I started plugging in the components on a mini breadboard using the Arduino Uno board and a text code by the Arduino IDE app to have the function of entering/pressing custom numbers as passcode to access the protected safe like when I press 1234# the lock must be unlocked (the servo motor will take action at a 90 degree angle) with a little tone from the puzzer, otherwise if the number doesn't have At least one number/symbol of the password. The puzzer (piezo) will emit a huge beep that acts as an emergency alarm. Meanwhile, the servo motor is supposed to take no action as shown in the next video.

The main idea of LED fade is to make the LED using an Arduino Uno board and a breadboard reach its highest light-emitting point (at 255) and gradually return to the zero state in the next second and so on.

Then I found that I could control the LED light by typing the numbers chosen in the range 0 to 255 where 255 is the max. value and 0 is the lowest. Thus, any numbers assigned between them can radiate light with a certain amount of illumination.