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

Voice Based Notice Board Using Android

A notice board updated by voice. The user speaks the notice into an Android app, which converts it to text and sends it over Bluetooth to an 8051 that displays it on the board.

Components & cost

What is the Voice Based Notice Board Using Android project?

A notice board updated by voice. The user speaks the notice into an Android app, which converts it to text and sends it over Bluetooth to an 8051 that displays it on the board.

Key facts

Type
Final year project · Intermediate
Suitable for
Diploma capstone and B.E / B.Tech final year
Build time
4 to 6 weeks
Estimated component cost
₹2,400 – ₹3,600
Guidance from
₹9,999 (Hardware / IoT Final Year)

How the Voice Based Notice Board Using Android 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 Push buttons and switches provide manual inputs and the power switch.
  3. The 8051 microcontroller with board runs the embedded C program that scans inputs and controls the outputs through its four I/O ports.
  4. The Bluetooth module links the circuit to a smartphone app so the user can send commands or receive readings.
  5. The 16×2 LCD with I2C adapter shows readings, status and messages to the user.
  6. The LEDs indicate status.

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
8051 (AT89S52) microcontroller with board1Runs the embedded C program that scans inputs and controls the outputs through its four I/O ports.₹300
Push buttons and switches2Provide manual inputs and the power switch.₹80
Bluetooth module (HC-05)1Links the circuit to a smartphone app so the user can send commands or receive readings.₹280
16×2 LCD with I2C adapter1Shows readings, status and messages to the user.₹220
LEDs (assorted)1Indicate status.₹20
12 V power adapter / step-down transformer1Supplies stable low-voltage power from the mains.₹250
Passive components, PCB and wiring kit1Crystal oscillator, resistors (assorted), capacitors (assorted), transistors / MOSFETs, cables, connectors and jumper wires, diodes, PCB / breadboard and ICs and IC sockets.₹445
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₹2,400 – ₹3,600

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₹2,400 – ₹3,600
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

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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 Voice Based Notice Board Using Android project?

A notice board updated by voice. The user speaks the notice into an Android app, which converts it to text and sends it over Bluetooth to an 8051 that displays it on the board.

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 Push buttons and switches provide manual inputs and the power switch. The 8051 microcontroller with board runs the embedded C program that scans inputs and controls the outputs through its four I/O ports. The Bluetooth module links the circuit to a smartphone app so the user can send commands or receive readings.

What is the architecture of the 8051 microcontroller?

The 8051 is an 8-bit Harvard-architecture microcontroller with 4 KB ROM (8 KB in AT89S52), 128 bytes RAM, four 8-bit I/O ports, two 16-bit timers, a UART and five interrupt sources.

Why is a pull-up resistor needed with a push button?

Without it the input pin floats and reads random values. The pull-up keeps it HIGH until the button connects it to ground.

How does the HC-05 Bluetooth module communicate with the microcontroller?

It uses UART serial at 9600 baud by default. Data typed in the phone app is received by the module and passed to the controller's RX pin as serial characters.

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.

Why is a resistor connected in series with an LED?

It limits the current to a safe value (about 10–20 mA). Without it, the LED would draw too much current and burn out. R = (supply voltage − LED voltage) ÷ current.

Explain the block diagram of your project.

The input section senses the real-world quantity, the 8051 microcontroller with board processes it according to the program, and the output section acts locally and sends the data or alert wirelessly. The power supply section feeds every block.

Which communication protocols are used between the modules?

UART (serial) for the GSM, GPS, Bluetooth or fingerprint modules and 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.

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Want to build Voice Based Notice Board Using Android?

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