E&TC / ECE · Embedded and digital electronics · Final year project

Home Air Quality Monitoring System

A home air quality monitor. It measures carbon dioxide, humidity and temperature inside and outside the room and displays them, so residents know when to ventilate.

Components & cost

What is the Home Air Quality Monitoring System project?

A home air quality monitor. It measures carbon dioxide, humidity and temperature inside and outside the room and displays them, so residents know when to ventilate.

Key facts

Type
Final year project · Beginner to intermediate
Suitable for
Diploma capstone and B.E / B.Tech final year
Build time
3 to 4 weeks
Estimated component cost
₹2,200 – ₹3,200
Guidance from
₹9,999 (Hardware / IoT Final Year)

How the Home Air Quality Monitoring System works

  1. 12 V power adapter / step-down transformer supplies the circuit; a regulator gives the controller and sensors a steady 5 V.
  2. The Arduino Uno R3 reads the inputs, runs the decision logic written in C/C++ and drives the outputs.
  3. The 16×2 LCD with I2C adapter shows readings, status and messages to the user.

Block diagram

Components list and cost

Typical prices from Indian online stores and electronics markets (Lamington Road, Budhwar Peth, SP Road). Buy from one store where you can to save on shipping.

ComponentQtyWhat it doesApprox. cost
Arduino Uno R31Reads the inputs, runs the decision logic written in C/C++ and drives the outputs.₹550
16×2 LCD with I2C adapter1Shows readings, status and messages to the user.₹220
12 V power adapter / step-down transformer1Supplies stable low-voltage power from the mains.₹250
Passive components, PCB and wiring kit1Resistors (assorted), capacitors (assorted), PCB / breadboard and cables, connectors and jumper wires.₹310
Wiring, PCB, soldering and enclosure1Project overhead₹450
Demo model base / mounting board1Project overhead₹500
Testing spares and replacements1Project overhead₹300
Estimated totalVaries with brand, quality and city₹2,200 – ₹3,200

Prices are estimates for budgeting. We confirm the bill of materials when your design is frozen, and components are charged at actual cost with bills.

How much does this project cost?

OptionWhat you getCost
Components onlyYou buy the parts and build it yourself₹2,200 – ₹3,200
Hardware / IoT Final YearWorking model or guided build, Circuit diagram and bill of materials, Firmware / code with explanationfrom ₹9,999 + components
Capstone Project (CPE)Working project or model, Black book in MSBTE format, Step-by-step explanation₹9,999 + components
Diploma ITR100% working source code, Project report PDF, PPT₹1,999 + components

No GST and no hidden charges. Use the cost calculator for a quote with your deadline and add-ons, or see all plans.

Download the project brief (PDF)

Summary, working, components and cost and viva questions on one branded PDF to show your guide or team. To get it developed, contact us on WhatsApp.

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What you submit with this project

  • Working model with circuit diagram and program code
  • Project report or black book in your university's chapter order (block diagram, circuit, calculations, results)
  • Presentation for the review and final viva
  • Synopsis for topic approval, if your college asks for one

E&TC / ECE viva questions on this project

What is the aim of the Home Air Quality Monitoring System project?

A home air quality monitor. It measures carbon dioxide, humidity and temperature inside and outside the room and displays them, so residents know when to ventilate.

Explain the working of your project in short.

12 V power adapter / step-down transformer supplies the circuit; a regulator gives the controller and sensors a steady 5 V. The Arduino Uno R3 reads the inputs, runs the decision logic written in C/C++ and drives the outputs. The 16×2 LCD with I2C adapter shows readings, status and messages to the user.

What microcontroller is on the Arduino Uno and what are its key specifications?

The Uno uses the ATmega328P: 8-bit, 16 MHz clock, 32 KB flash, 2 KB SRAM, 14 digital I/O pins (6 PWM) and 6 analog inputs with a 10-bit ADC.

Why is an I2C adapter used with the LCD?

It reduces the wiring from about 10 pins to 2 (SDA and SCL), leaving more controller pins free for sensors.

How is 230 V AC converted to 5 V DC for the circuit?

A transformer steps down the voltage, a bridge rectifier converts AC to pulsating DC, a capacitor smooths it and a 7805 regulator gives a steady 5 V.

Explain the block diagram of your project.

The input section senses the real-world quantity, the Arduino Uno R3 processes it according to the program, and the output section displays the result and drives the actuators. The power supply section feeds every block.

Which communication protocols are used between the modules?

I2C for the display, RTC or motion sensor (only SDA and SCL lines). Each protocol was chosen because the module supports it and it uses the fewest pins.

What is the operating voltage of the circuit?

The controller and most sensors work at 5 V (ESP boards and some modules at 3.3 V). A 12 V adapter powers the board, and a regulator steps it down. Motors and relays get their own supply line so they do not reset the controller.

What is the difference between accuracy and precision?

Accuracy is how close a reading is to the true value. Precision is how close repeated readings are to each other. A sensor can be precise but inaccurate if it is not calibrated.

Academic use: Project Buddyy offers mentoring, guidance and reference material for learning. You stay responsible for following your institution's academic integrity rules and for understanding everything you submit.

Want to build Home Air Quality Monitoring System?

Send your college, deadline and team size. We confirm the scope, cost and what you will submit.