Arduino Weather Station with Multiple Sensors - Complete Wokwi Simulator Tutorial 2026

 

Step-by-Step Instructions for Wokwi Simulation

Project Overview

This weather station monitors temperature, humidity, rain detection, air quality, atmospheric pressure, and sunlight levels using Arduino Uno with DHT22, rain sensor, MQ-135 gas sensor, BMP180 pressure sensor, and LDR (Light Dependent Resistor), displaying data on a 20x4 LCD.

---

Step 1: Create New Wokwi Project

1. Go to https://wokwi.com
2. Click "New Project"
3. Select "Arduino Uno"

---

Step 2: Add All Components

Click the "+" button and add:

• 1x Arduino Uno (already included)
• 1x DHT22 Temperature & Humidity Sensor
• 1x LCD 20x4 with I2C Module
• 1x Rain Sensor Module
• 1x MQ-135 Gas Sensor (Air Quality)
• 1x BMP180 Barometric Pressure Sensor
• 1x Photoresistor (LDR) + 1x 10kΩ Resistor
• 4x LED (Blue, Red, Purple/Violet, Orange/Yellow)
• 4x 220Ω Resistors (for LEDs)
• 1x Breadboard

---

Step 3: Wiring Connections

Diagram.json:

{

  "version": 1,

  "author": "Anonymous maker",

  "editor": "wokwi",

  "parts": [

    {

      "type": "wokwi-breadboard",

      "id": "bb1",

      "top": 93,

      "left": 434.8,

      "attrs": { "color": "#eeefed" }

    },

    { "type": "wokwi-arduino-uno", "id": "uno", "top": -143.4, "left": 719.4, "attrs": {} },

    {

      "type": "wokwi-led",

      "id": "led1",

      "top": 174.4,

      "left": 647.4,

      "rotate": 180,

      "attrs": { "color": "blue" }

    },

    {

      "type": "wokwi-led",

      "id": "led2",

      "top": 174.4,

      "left": 781.8,

      "rotate": 180,

      "attrs": { "color": "red" }

    },

    {

      "type": "wokwi-led",

      "id": "led4",

      "top": 174.4,

      "left": 906.6,

      "rotate": 180,

      "attrs": { "color": "purple" }

    },

    {

      "type": "wokwi-led",

      "id": "led5",

      "top": 174.4,

      "left": 1021.8,

      "rotate": 180,

      "attrs": { "color": "orange" }

    },

    {

      "type": "wokwi-bmp180",

      "id": "bmp1",

      "top": -68.26504375416349,

      "left": -184.79089663380302,

      "attrs": {}

    },

    {

      "type": "wokwi-lcd2004",

      "id": "lcd1",

      "top": -166.4,

      "left": 1080.8,

      "attrs": { "pins": "i2c" }

    },

    {

      "type": "wokwi-gas-sensor",

      "id": "gas1",

      "top": 219.4,

      "left": 493.7,

      "rotate": 270,

      "attrs": {}

    },

    { "type": "wokwi-dht22", "id": "dht1", "top": -76.5, "left": 465, "attrs": {} },

    {

      "type": "wokwi-photoresistor-sensor",

      "id": "ldr1",

      "top": 236.9,

      "left": 388.3,

      "rotate": 270,

      "attrs": {}

    },

    {

      "type": "wokwi-bmp180",

      "id": "bmp2",

      "top": -58.665043754049485,

      "left": -175.19089663368902,

      "attrs": {}

    },

    {

      "type": "wokwi-resistor",

      "id": "r2",

      "top": 167.45,

      "left": 977.8,

      "rotate": 180,

      "attrs": { "value": "220" }

    },

    {

      "type": "wokwi-resistor",

      "id": "r3",

      "top": 43.2,

      "left": 383.45,

      "rotate": 90,

      "attrs": { "value": "220" }

    },

    {

      "type": "wokwi-resistor",

      "id": "r4",

      "top": 167.15,

      "left": 739.2,

      "attrs": { "value": "220" }

    },

    {

      "type": "wokwi-resistor",

      "id": "r5",

      "top": 167.15,

      "left": 864,

      "attrs": { "value": "220" }

    },

    {

      "type": "wokwi-resistor",

      "id": "r6",

      "top": 167.15,

      "left": 604.8,

      "attrs": { "value": "220" }

    },

    {

      "type": "wokwi-bmp180",

      "id": "bmp3",

      "top": 18.134956246862515,

      "left": -98.39089663277707,

      "attrs": {}

    },

    { "type": "wokwi-slide-switch", "id": "sw1", "top": -34, "left": 627.1, "attrs": {} },

    {

      "type": "wokwi-slide-potentiometer",

      "id": "pot1",

      "top": 33.8,

      "left": 1122.2,

      "attrs": { "travelLength": "30" }

    },

    {

      "type": "wokwi-bmp180",

      "id": "bmp4",

      "top": -237.49316363124655,

      "left": 384.92513662480815,

      "attrs": {}

    }

  ],

  "connections": [

    [ "bb1:55t.c", "uno:1", "violet", [ "v-86.4", "h48", "v-220.8", "h-67.2" ] ],

    [ "bb1:62t.d", "bb1:tn.50", "black", [ "v0" ] ],

    [ "bb1:43t.c", "uno:2", "violet", [ "v-86.4", "h-172.8", "v-220.8", "h249.6" ] ],

    [ "bb1:50t.c", "bb1:tn.40", "black", [ "v-48", "h-9.6" ] ],

    [ "bb1:30t.c", "uno:3", "violet", [ "v-76.8", "h-57.6", "v-240", "h249.6" ] ],

    [ "bb1:37t.d", "bb1:tn.30", "black", [ "v0" ] ],

    [ "bb1:16t.c", "uno:4", "violet", [ "v-326.4", "h326.4" ] ],

    [ "bb1:23t.d", "bb1:tn.18", "black", [ "v0" ] ],

    [ "lcd1:GND", "uno:GND.3", "black", [ "h-19.2", "v192", "h0", "v9.6", "h-134.4" ] ],

    [ "lcd1:VCC", "bb1:tp.38", "red", [ "h-9.6", "v211.3", "h-19.2" ] ],

    [ "dht1:VCC", "bb1:tp.16", "red", [ "v48", "h172.8" ] ],

    [ "dht1:GND", "bb1:tn.17", "black", [ "v28.8", "h153.6" ] ],

    [ "bb1:1t.c", "bb1:tp.1", "red", [ "v0" ] ],

    [ "bb1:2t.a", "bb1:tn.1", "black", [ "v0" ] ],

    [ "bb1:4t.a", "uno:A0", "white", [ "v-86.4", "h441.6" ] ],

    [ "bb1:3t.a", "uno:6", "violet", [ "v-9.6", "h57.6", "v-192", "h374.4" ] ],

    [ "bb1:12t.a", "bb1:tn.9", "black", [ "v0" ] ],

    [ "bb1:13t.a", "bb1:tp.10", "red", [ "v-19.2", "h9.6", "v-19.2" ] ],

    [ "bb1:10t.a", "uno:A1", "white", [ "v-124.8", "h384" ] ],

    [ "sw1:1", "bb1:tp.15", "red", [ "v0" ] ],

    [ "sw1:2", "uno:8", "violet", [ "v9.6", "h144.1", "v-86.4", "h105.6" ] ],

    [ "sw1:3", "bb1:tn.15", "black", [ "v38.4", "h-9.4", "v76.8" ] ],

    [ "pot1:VCC", "bb1:tp.31", "red", [ "h-28.8", "v-76.8", "h-268.8" ] ],

    [ "pot1:SIG", "bb1:tn.48", "black", [ "h-67.2", "v37.6", "h-38.4" ] ],

    [ "pot1:GND", "uno:A2", "white", [ "v0", "h24.4", "v-48", "h-403.2" ] ],

    [ "dht1:SDA", "r3:1", "red", [ "v9.6", "h-57.5", "v-38.4", "h-19.2" ] ],

    [ "r3:2", "bb1:tp.16", "red", [ "h67.2", "v-1.2", "h0" ] ],

    [ "dht1:SDA", "uno:5", "violet", [ "v9.6", "h316.9", "v-86.4", "h124.8" ] ],

    [ "uno:5V", "bb1:tp.28", "red", [ "v19.1", "h-92.2" ] ],

    [ "uno:GND.2", "bb1:tn.26", "black", [ "v38.3", "h-130.5", "v28.8" ] ],

    [ "lcd1:SDA", "uno:A4", "gold", [ "h0" ] ],

    [ "lcd1:SCL", "uno:A5", "blue", [ "h0" ] ],

    [ "led1:A", "bb1:22t.e", "", [ "$bb" ] ],

    [ "led1:C", "bb1:23t.e", "", [ "$bb" ] ],

    [ "led2:A", "bb1:36t.e", "", [ "$bb" ] ],

    [ "led2:C", "bb1:37t.e", "", [ "$bb" ] ],

    [ "led5:A", "bb1:61t.e", "", [ "$bb" ] ],

    [ "led5:C", "bb1:62t.e", "", [ "$bb" ] ],

    [ "gas1:AOUT", "bb1:10t.e", "", [ "$bb" ] ],

    [ "gas1:DOUT", "bb1:11t.e", "", [ "$bb" ] ],

    [ "gas1:GND", "bb1:12t.e", "", [ "$bb" ] ],

    [ "gas1:VCC", "bb1:13t.e", "", [ "$bb" ] ],

    [ "ldr1:VCC", "bb1:1t.e", "", [ "$bb" ] ],

    [ "ldr1:GND", "bb1:2t.e", "", [ "$bb" ] ],

    [ "ldr1:DO", "bb1:3t.e", "", [ "$bb" ] ],

    [ "ldr1:AO", "bb1:4t.e", "", [ "$bb" ] ],

    [ "r2:1", "bb1:61t.d", "", [ "$bb" ] ],

    [ "r2:2", "bb1:55t.d", "", [ "$bb" ] ],

    [ "r4:1", "bb1:30t.d", "", [ "$bb" ] ],

    [ "r4:2", "bb1:36t.d", "", [ "$bb" ] ],

    [ "r5:1", "bb1:43t.d", "", [ "$bb" ] ],

    [ "r5:2", "bb1:49t.d", "", [ "$bb" ] ],

    [ "r6:1", "bb1:16t.d", "", [ "$bb" ] ],

    [ "r6:2", "bb1:22t.d", "", [ "$bb" ] ],

    [ "led4:A", "bb1:49t.e", "", [ "$bb" ] ],

    [ "led4:C", "bb1:50t.e", "", [ "$bb" ] ]

  ],

  "dependencies": {}

}

DHT22 Sensor (Temperature & Humidity)

DHT22 Pin	Arduino Pin
VCC	5V
DATA	Pin 2
GND	GND

LCD 20x4 with I2C

I2C LCD Pin	Arduino Pin
VCC	5V
GND	GND
SDA	A4
SCL	A5

Rain Sensor

Rain Sensor	Arduino Pin
VCC	5V
GND	GND
A0 (Analog)	A0

MQ-135 Gas Sensor (Air Quality)

MQ-135 Pin	Arduino Pin
VCC	5V
GND	GND
A0	A1

BMP180 Pressure Sensor

BMP180 Pin	Arduino Pin
VCC	3.3V
GND	GND
SDA	A4 (shared with LCD)
SCL	A5 (shared with LCD)

LDR (Light Sensor)

• One end of LDR → 5V
• Other end of LDR → A2 and one end of 10kΩ resistor
• Other end of 10kΩ resistor → GND

Code:

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 4);

#include <DHT.h>

#define DHTPIN 5

#define RAINPIN 8

#define BARPIN A2

#define AIRPIN A1

#define LDRPIN A0

#define DHTTYPE DHT22

DHT dht(DHTPIN, DHTTYPE);

#define  LedRain 1

#define  LedSun 2

#define  LedTemp 3

#define  LedAir 4

int temperature;

int humidity;

float lightPercent;

float airPercent;

float rain;

float pressure;

int rainState;

int barValue;  

int airValue;

void setup() {

Serial.begin(9600);

lcd.init();

lcd.backlight();

lcd.setCursor(4, 0);

lcd.print("METEOSTAT");

lcd.setCursor(2, 1);

lcd.print("STEM UMSSN 2026");

lcd.setCursor(4, 2);

lcd.print("Team Xenodi");

delay(2000);

pinMode(LedRain, OUTPUT);

pinMode(LedSun, OUTPUT);

pinMode(LedTemp, OUTPUT);

pinMode(LedAir, OUTPUT);

pinMode(LDRPIN, INPUT);

pinMode(AIRPIN, INPUT);

pinMode(RAINPIN, INPUT);

pinMode(BARPIN, INPUT);

dht.begin();

}

void loop() {

int rainState = digitalRead(RAINPIN);

int barRaw  = analogRead(BARPIN);

int pressure = map(barRaw, 0, 1023, 950, 1050);

int airRaw  = analogRead(AIRPIN);

int airPercent = map(airRaw, 0, 1023, 0, 100);

int lightRaw = analogRead(LDRPIN);      

int lightPercent = map(lightRaw, 0, 1023, 0, 100);

float temperature = dht.readTemperature();

float humidity = dht.readHumidity();

Serial.print("Humidity: ");

Serial.print((int)humidity);

Serial.println("%");

Serial.print("Temp: ");

Serial.print((int)temperature);

Serial.println("C");

Serial.println(rainState);

Serial.print("Rain: ");

if (rainState == HIGH) {

    Serial.println("YES");

  }

  else {

    Serial.println("NO");

  }

Serial.print("Air Quality: ");

Serial.print((int)airPercent);

Serial.print("%");

if (airPercent < 30) {

  Serial.println(" Safe");

} else if (airPercent < 60 and airPercent > 31) {

  Serial.println(" Moderate");

} else if (airPercent < 100 and airPercent > 61) {

  Serial.println(" GET OUT!!");

}

Serial.print("Pre: ");

Serial.print(pressure);

Serial.println("hPa");

Serial.print("Sun: ");

Serial.print((int)lightPercent);

Serial.print("%");

if (lightPercent < 30) {

    Serial.println(" SAFE ");

  } else if (lightPercent < 60 and lightPercent > 31) {

    Serial.println(" MEDIUM");

  } else if (lightPercent <100 and lightPercent > 61) {

    Serial.println(" TAKE COVER!!");

  }

delay(100);

lcd.clear();

lcd.setCursor(0,0);

 lcd.print("Sun: ");

lcd.print((int)lightPercent);

lcd.print("%");

if (lightPercent < 30) {

    lcd.print(" SAFE ");

  } else if (lightPercent < 60 and lightPercent > 31) {

    lcd.print(" MEDIUM");

  } else if (lightPercent <100 and lightPercent > 61) {

    lcd.print(" TAKE COVER!!");

  }

lcd.setCursor(0,1);

lcd.print("Temp: ");

lcd.print((int)temperature);

lcd.print("C");

lcd.print("      ");

lcd.setCursor(0,2);

if (rainState == HIGH) {

    lcd.print("Rain: YES");

  } else {

    lcd.print("Rain : NO");

  }

lcd.setCursor(0,3);

lcd.print("Air: ");

lcd.print((int)airPercent);

lcd.print("%");

if (airPercent < 30) {

lcd.print(" Safe");

} else if (airPercent < 60 and airPercent > 31) {

lcd.print(" Moderate");

} else if (airPercent < 100 and airPercent > 61) {

lcd.print(" GET OUT!!");

}

delay(100);

    // Rain LED

    if (RAINPIN == HIGH) {

        digitalWrite(LedRain, HIGH);

    } else {

        digitalWrite(LedRain, LOW);

    }

    // Air quality LED

    if (airPercent > 60) {

        digitalWrite(LedAir, HIGH);

    } else {

        digitalWrite(LedAir, LOW);

    }

    // Temperature LED

    if (temperature > 35) {

        digitalWrite(LedTemp, HIGH);

    } else {

        digitalWrite(LedTemp, LOW);

    }

    // Sunlight LED

    if (lightPercent > 70) {

        digitalWrite(LedSun, HIGH);

    }

    else

    {

      digitalWrite(LedSun, LOW);

    }

}

   

LED Indicators

LED Color	Function	Arduino Pin	Connection
Blue	Humidity	Pin 8	Anode → 220Ω → Pin 8, Cathode → GND
Red	Temperature	Pin 9	Anode → 220Ω → Pin 9, Cathode → GND
Purple	Rain	Pin 10	Anode → 220Ω → Pin 10, Cathode → GND
Orange	Sun/Light	Pin 11	Anode → 220Ω → Pin 11, Cathode → GND

---

Step 4: Install Required Libraries

1. Click "Library Manager" (book icon)
2. Add these libraries:
• DHT sensor library (by Adafruit)
• LiquidCrystal I2C
• Adafruit BMP085 Library (works with BMP180)
• Wire (built-in for I2C)

Step 5: Start Simulation

1. Click the green "Start Simulation" button
2. Open Serial Monitor to see detailed readings
3. Observe the LCD display and LED indicators

---

Step 6: Test Sensor Interactions

Adjust DHT22 (Temperature/Humidity)

• Click on DHT22 sensor
• Adjust temperature slider (affects red LED)
• Adjust humidity slider (affects blue LED)

Simulate Rain

• Click on rain sensor
• Lower the value to simulate rain (purple LED turns on)
• Increase to simulate dry conditions

Change Air Quality

• Click on MQ-135 sensor
• Increase value to simulate poor air quality
• Watch for "GET OUT!!" message when quality is bad

Adjust Light Level

• Click on LDR/Photoresistor
• Change resistance to simulate day/night
• Orange LED indicates bright conditions

Pressure Sensor

• BMP180 shows atmospheric pressure
• Displays in hPa on LCD

---

Expected Behavior:

LCD Display Shows:

• Line 1: Current humidity percentage
• Line 2: Current temperature in Celsius
• Line 3: Atmospheric pressure in hPa
• Line 4: Sun percentage and air quality status

LED Indicators:

• 🔵 Blue LED: ON when humidity > 50%
• 🔴 Red LED: ON when temperature > 25°C
• 🟣 Purple LED: ON when rain detected
• 🟠 Orange LED: ON when bright sunlight detected

Serial Monitor Output:

• Detailed readings every 2 seconds
• Easy-to-read formatted data