Smart Flex System - Sign Language to Text

IEEM Mini Project | AISSMS College of Engineering, Pune
SE R&A Batch-C | Guide: R. Wani Sir

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📋 Overview

The Smart Flex System is an innovative Arduino-based project that converts finger bend gestures (detected via a flex sensor) into text messages. The system displays real-time status on an LCD screen and communicates via Bluetooth, making it ideal for assistive communication devices and sign language interpretation.

✨ Features

• Flex Sensor-Based Gesture Recognition - Detects finger bending and converts to status messages
• LCD Display - Real-time status display on 16x2 I2C LCD ("I am Fine" / "Need Help!")
• Bluetooth Communication - Wireless data transmission and remote command interface
• Buzzer Alerts - Audio feedback for emergency detection
• EEPROM Calibration Storage - Persistent sensor calibration across power cycles
• Command Interface - Full-featured serial terminal with multiple commands
• Auto-Calibration - Guided calibration process with live ADC value display

🔧 Hardware Required

Component	Specification	Connection
Microcontroller	Arduino Uno	-
Flex Sensor	2.2" / 4.5"	Analog Pin A0
LCD Display	16x2 I2C	SDA, SCL
Bluetooth Module	HC-05	RX: Pin 10, TX: Pin 11
Buzzer	Active/Passive	Digital Pin 9
Power Supply	9V Battery / USB	-

📁 Repository Structure

smart-flex-system/
├── smart_flex_system.ino    # Main Arduino firmware (v8.1)
├── README.md                # Project documentation
└── .gitignore              # Git ignore file

🚀 Getting Started

Prerequisites

• Arduino IDE (v1.8.x or higher)
• Required Libraries:
  • Wire.h (built-in)
  • LiquidCrystal_I2C.h (Download)
  • SoftwareSerial.h (built-in)
  • EEPROM.h (built-in)

Installation Steps

1. Clone the repository

   git clone https://github.com/arise-om/smart-flex-system.git
   cd smart-flex-system

2. Install required libraries

   • Open Arduino IDE
   • Go to Sketch → Include Library → Manage Libraries
   • Search and install LiquidCrystal_I2C

3. Wire the circuit (see circuit diagram below)

4. Upload the code

   • Open smart_flex_system.ino in Arduino IDE
   • Select Tools → Board → Arduino Uno
   • Select the correct COM port
   • Click Upload

5. First Run Calibration

   • Connect via Bluetooth or Serial Monitor (9600 baud)
   • System will auto-start calibration if needed
   • Follow on-screen instructions

📟 Bluetooth Commands

Connect via Bluetooth terminal (9600 baud) and use these commands:

Command	Description
HELP	Display all available commands
CAL	Start manual calibration process
STATUS	Show current sensor calibration values
RESET	Reset calibration to defaults
INFO	Display system and build information
ECHOON	Enable serial output (default: ON)
ECHOOFF	Disable serial output
BUZZON	Enable buzzer alerts (default: ON)
BUZZOFF	Disable buzzer alerts

🎯 Usage

1. Power On - System displays welcome screens
2. Calibration - Auto-calibrates on first use
3. Normal Operation - Displays "I am Fine." when flex sensor is straight
4. Help Signal - Displays "Need Help!" and triggers buzzer when sensor is bent beyond threshold (75%)
5. Bluetooth Monitoring - Real-time data streaming to connected device

🔬 Calibration Process

1. Send CAL command via Bluetooth
2. Step 1: Keep sensor STRAIGHT for 5 seconds (watch live ADC values)
3. Step 2: BEND sensor fully for 5 seconds
4. System automatically saves calibration to EEPROM
5. Confirmation beep and LCD message

🛠️ Troubleshooting

Issue	Solution
LCD not displaying	Check I2C address (default: 0x27), verify SDA/SCL connections
Bluetooth not connecting	Ensure HC-05 is paired, check baud rate (9600)
Inaccurate readings	Run CAL command for recalibration
No buzzer sound	Check buzzer polarity, verify pin 9 connection, try BUZZON
Values not saving	EEPROM issue - power cycle and recalibrate

📊 Technical Specifications

• Sensor Range: 0-1023 ADC units
• Bend Detection Threshold: 75% (configurable in code)
• Update Rate: ~300ms (configurable)
• Bluetooth Baud Rate: 9600
• Serial Baud Rate: 9600
• Power Consumption: ~150mA @ 5V
• Operating Voltage: 5V DC

🎓 Project Information

Institution: AISSMS College of Engineering, Pune
Department: Electronics Engineering
Batch: SE R&A, Batch-C
Project Type: IEEM (Innovation in Electronics Engineering & Management) Mini Project
Guide: Prof. R. Wani Sir
Version: 8.1
Date: November 2025

📝 Code Structure

The firmware is organized into functional sections:

• Pin Configuration - Hardware pin definitions
• Object Initialization - LCD, Bluetooth, and sensor setup
• Calibration System - EEPROM storage and auto-calibration
• Welcome Screens - Startup display sequence
• Main Loop - Banner scrolling, sensor reading, status display
• Command Handler - Bluetooth command processing
• Utility Functions - Buzzer patterns, display helpers

🤝 Contributing

Contributions, issues, and feature requests are welcome! Feel free to check the issues page.

📄 License

This project is open-source and available for educational purposes.

👥 Team

Developed by SE R&A students at AISSMS COE, Pune.

📞 Contact

For queries or collaboration:

• GitHub: @arise-om
• Repository: smart-flex-system

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