Smart-Humdifier-using-DHT11-Arduino

This smart humidifier will help you to control humidifier using a Humidifier driver, Arduino Nano as well as a DHT11 sensor.

When humidity is below 40% humidifier will work on continous mode, And if humidity is between 40% to 65% humidifier will work on with pauses mode, As well as if humidity exceeded 65% humidifier will turn off as too much humidity is not good. (*if this humidity range is not satisfying for you you can adjust maximum humidity and low humidity levels from the code)

Why It’s Important to Manage the Humidity in Your House

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contact on:

alham@duck.com

parts:

• Arduino Nano/uno
• DHT11 sensor
• Humidifier Driver board
• 5V Relay

first you should add 'DHTLib.zip' .zip library to your Arduino IDE. then open the code from Arduino IDE and upload the code to your Arduino board.

see circuit diagram to see clearly

Connect Arduino pin 2 to relay signal in pin.

Connect Arduino pin A2 to DHT11 sensor's sata out pin.

connect all Gnd pins

connect all Vcc pins

*you can either connect 5V from arduino board or humidifier via usb port or you can connect external 5V supply to powerup .

CODE:

// Smart_Humidifier_Using_DHT11_-_Arduino
// code written by alham,
// last modified date 2022.4.13
// follow on,
                // twitter :-https://twitter.com/alham__aa
                // github :-https://github.com/MrAlham
//contact from: alham@duck.com

#include<Arduino.h>
#include<dht.h>  // include library for working with dht11

#define humidifier 2        //humidifier's switch(relay) connects to
#define sensepin  A2        //dht 11 sensor's data out pin connects to

dht dht11;
int temp, humidity, state;
float val;
int previous_state = 0;
int max_humidity = 65;
int low_humidity = 40;

void setup() {

  Serial.begin(9600);     //openning Serial monitor with baud rate of 9600
  pinMode (humidifier, OUTPUT);       //setting relay's pin as output (humidifier's switch)

}

void loop() {
  val = dht11.read11(sensepin);       //getiing values from sensor
  delay(200);
  humidity = (dht11.humidity);                   //assigning humidity readings to variables
  humidity = (humidity - (humidity * 20 / 100)); //-20% to keep accuracy
  temp = (dht11.temperature);                    //assigning temperature readings to variabl
  temp = temp - 2;                               //-2 to keep accuracy
  delay(200);

  Serial.print("Humidity=  ");             //printing humidity on
  Serial.println(humidity);                //the serial monitor
  Serial.print("Temperature=  ");          //printing temperature on
  Serial.println(temp);                    //the serial monitor
  delay(200);

  if (humidity >= max_humidity) {
    if (previous_state != 0) {
      state_zero();
    }
  }

  if (humidity <= low_humidity) {
    if (previous_state != 1) {
      state_one();
    }
  }

  if (low_humidity + 1 <= humidity & max_humidity - 1 > humidity) {
    if (previous_state = 2) {
      state_two();
    }
  }
  Serial.println("### _starting delay period_ ###");
  delay (15000);
}
void state_zero() {
  if (state == 0) {
    Serial.println("switch state is '0' ");
    previous_state = 0;
  } else if (state == 1)
  {
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =2
    delay(500);
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =0
    delay(500);

    Serial.println("switch state is '0' ");
    state = 0;
    previous_state = 0;
  } else if (state == 2)
  {
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =0
    delay(500);
    Serial.println("switch state is '0' ");
    state = 0;
    previous_state = 0;
  }

}

void state_one() {
  if (state == 1) {
    Serial.println("switch state is '1' ");
    previous_state = 1;
  } else if (state == 2)
  {
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =0
    delay(500);
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =1
    delay(500);

    Serial.println("switch state is '1' ");
    state = 1;
    previous_state = 1;

  } else if (state == 0)
  {
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =1
    delay(500);
    Serial.println("switch state is '1' ");
    state = 1;
    previous_state = 1;
  }

}

void state_two() {
  if (state == 2) {
    Serial.println("switch state is '2' ");
    previous_state = 2;
  } else if (state == 0)
  {
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =1
    delay(500);
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =2
    delay(500);

    Serial.println("switch state is '2' ");
    state = 2;
    previous_state = 2;
  } else if (state == 1)
  {
    digitalWrite(humidifier, HIGH);
    delay(500);
    digitalWrite(humidifier, LOW);      //state =2
    delay(500);
    Serial.println("switch state is '2' ");
    state = 2;
    previous_state = 2;
  }

}

If yoy have any problem feel free to contact me. Thank you,