FM Receiver Using Arduino

📌 Project Overview

This project presents the design and development of an FM Receiver using the Arduino UNO microcontroller and the RDA5807M FM tuner module.
It demonstrates how embedded systems can replace traditional analog circuits with digital tuning and control to achieve higher precision, flexibility, and ease of use.

The system receives FM radio signals, decodes them through the RDA5807M chip, and outputs high-quality audio through earphones or a speaker.
A simple LCD interface and push-button control make the system user-friendly and educational.

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🎯 Objectives

• Build a digital FM radio receiver using Arduino.
• Eliminate traditional analog tuning circuits.
• Enable frequency switching through a push-button interface.
• Display frequency information on an LCD screen.
• Provide an efficient and educational embedded system prototype.

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⚙️ Components Used

Component	Description
Arduino UNO	Central microcontroller that controls the system.
RDA5807M Module	FM receiver IC for decoding and tuning radio frequencies.
LCD Display (16x2)	Displays current frequency and status.
Push Button	Used to change FM channels or cycle frequencies.
Jumper Wires	Used for circuit connections.
Earphones / Speaker	Audio output device.

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🧩 Circuit Description

• The Arduino UNO communicates with the RDA5807M using I²C protocol (SDA and SCL pins).
• The LCD module is also connected via I²C, minimizing the number of required pins.
• On startup, the Arduino initializes the RDA5807M at a default FM frequency (e.g., 93.5 MHz).
• Every press of the push button switches to the next stored frequency in a predefined list.
• Audio is output from the RDA5807M module to an earphone or small speaker.
• The system operates on 5V DC power supplied by the Arduino board.

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🔄 Working Principle

1. Initialization – The Arduino initializes the RDA5807M module and sets a default FM frequency.
2. User Input – Each button press sends a signal to the Arduino to change the frequency.
3. I²C Communication – Arduino communicates new tuning commands to the RDA5807M module.
4. Signal Reception – The module receives the corresponding FM signal and demodulates the audio.
5. Output – Clear audio is output through earphones or a speaker, and the LCD displays the current frequency.

This digital approach ensures accuracy and stability compared to analog FM tuners, which often suffer from drift and noise.

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🧠 Working Features

• Digital tuning using a push button.
• Stable and noise-free FM reception.
• LCD display shows tuned frequency.
• Low power consumption.
• Portable and easy to use.
• Uses only low-cost components.

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📊 Advantages

• Replaces analog tuning with digital precision.
• Compact and lightweight hardware.
• Cost-effective solution for hobbyists and students.
• Demonstrates real-world use of I²C communication.
• Serves as a great educational project for electronics and embedded systems.

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⚠️ Limitations

• Limited to FM frequency range supported by RDA5807M (87.5–108 MHz).
• Audio quality depends on antenna and local signal strength.
• Only basic channel switching (no full scan or memory).

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🧪 Output

• The LCD displays the active frequency and changes with each button press.
• The system successfully plays FM audio through earphones or small speakers.
• Demonstrates clear frequency control and switching between stations.

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🧩 Circuit Connection Summary

Arduino Pin	Connected To	Description
5V	VCC (RDA5807M + LCD)	Power Supply
GND	GND (RDA5807M + LCD)	Common Ground
A4	SDA	I²C Data Line
A5	SCL	I²C Clock Line
D2	Push Button	Frequency Change Input

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📥 Installation Steps

1. Download Arduino IDE
   https://www.arduino.cc/en/software

2. Install Required Libraries
   In Arduino IDE, go to Sketch → Include Library → Manage Libraries and install:

   • Wire.h
   • RDA5807M.h (FM module library)
   • LiquidCrystal_I2C.h

3. Upload Code to Arduino UNO
   Connect the Arduino board and upload the .ino file.

4. Make Connections
   Follow the circuit diagram and connect modules accordingly.

5. Power the Board
   Once powered, the LCD will show the current frequency and audio output will play.

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▶️ How to Use

1. Power on the Arduino system.
2. Default frequency will appear on the LCD.
3. Press the button to change the FM station.
4. Connect earphones or speaker to hear audio.
5. Observe frequency updates on the LCD screen.

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📈 Applications

• Educational tool for learning radio frequency communication.
• Embedded systems and IoT-based communication projects.
• Portable digital FM radio device.
• Demonstration model for engineering and electronics students.

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🔮 Future Scope

• Add auto-scan for available FM channels.
• Include volume control and mute options.
• Integrate Bluetooth module for wireless audio output.
• Display station name using RDS data decoding.
• Power via battery for portability.

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👨‍💻 Authors

• Lakshmanan S – 2022504310

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🏁 Conclusion

This project successfully demonstrates a digital FM receiver using Arduino UNO and RDA5807M.
It provides a cost-effective and reliable alternative to analog FM radios with better control and precision.
By merging embedded systems with digital signal communication, this project shows how simple microcontroller-based solutions can modernize traditional analog systems.

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