🔬 Arduino Sensors Laboratory

ECE NTUA | 8th Semester | Sensors Course

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📋 Overview

This repository contains Arduino code for various sensor experiments and projects completed during the Sensors course at the School of Electrical and Computer Engineering (ECE) of the National Technical University of Athens (NTUA).

The laboratory exercises explore different types of sensors, their characteristics, calibration methods, and practical applications in embedded systems.

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🧪 Laboratory Experiments

1. 📏 Distance Sensor (Ultrasonic + Temperature Compensation)

Directory: distance_sensor/

• Sensor Type: HC-SR04 Ultrasonic Sensor + DHT11 Temperature/Humidity Sensor
• Features:
  • Temperature-compensated distance measurement
  • Sound speed calculation based on environmental conditions
  • Buzzer alert for objects closer than 20cm
  • Range: 2-400 cm
• Key Components:
  • Ultrasonic sensor (HC-SR04)
  • DHT11 temperature/humidity sensor
  • Buzzer for proximity alerts

2. 🧲 Hall Effect Sensor

Directory: hall_sensor/

• Sensor Type: Hall Effect Magnetic Field Sensor
• Features:
  • Magnetic field strength measurement in mT (milliTesla)
  • LED brightness control based on field intensity
  • Real-time magnetic field visualization
  • Offset calibration
• Applications:
  • Magnetic field detection
  • Position sensing
  • Current measurement (indirect)

3. 💡 Light Sensor (LDR)

Directory: light_sensor/

• Sensor Type: Light Dependent Resistor (LDR)
• Features:
  • Dual operation modes (Analog/Digital)
  • Serial command interface ('A' for analog, 'D' for digital)
  • Frequency-based audio feedback
  • Threshold-based digital output
• Applications:
  • Ambient light monitoring
  • Automatic lighting control
  • Day/night detection

4. 🌡️ Temperature Sensor

Directory: temp_sensor/

• Sensor Type: LM35 Temperature Sensor
• Features:
  • Temperature measurement in Celsius
  • Multi-level LED indicator system:
    • 🟢 Green: ≤ 25°C
    • 🟠 Green + Orange: 25-35°C
    • 🔴 All LEDs: > 35°C
• Applications:
  • Environmental monitoring
  • Temperature control systems
  • HVAC applications

5. ⚡ Flux Gate Magnetometer

Directory: flux_gate_project/

• Sensor Type: Flux Gate Magnetometer
• Features:
  • Peak-to-peak voltage measurement
  • High-frequency sampling (~100 kHz)
  • Statistical signal analysis
  • Precise magnetic field detection
• Applications:
  • Geomagnetic field measurement
  • Navigation systems
  • Scientific research

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🛠️ Hardware Requirements

Common Components:

• Arduino Uno/Nano
• Breadboard and jumper wires
• USB cable for programming

Sensor-Specific Components:

Experiment	Required Components
Distance Sensor	HC-SR04, DHT11, Buzzer, Resistors
Hall Sensor	Hall effect sensor, LED, Resistors
Light Sensor	LDR, Speaker/Buzzer, Resistors
Temperature Sensor	LM35, 3x LEDs (Green, Orange, Red), Resistors
Flux Gate	Flux gate sensor, Signal conditioning circuit

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📚 Software Requirements

• Arduino IDE (v1.8.0 or later)
• Libraries:
  • dht.h (for DHT11 sensor)
  • Standard Arduino libraries

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🚀 Getting Started

1. Clone the repository:

   git clone https://github.com/AntonisAk/Sensors_Arduino_Labs.git
   cd Sensors_Arduino_Labs

2. Install required libraries:

   • Download and install the DHT library for the distance sensor project
   • Extract DHTLib.zip in the distance_sensor folder

3. Upload to Arduino:

   • Open the desired .ino file in Arduino IDE
   • Select your board and port
   • Upload the code

4. Connect hardware:

   • Follow the pin configurations defined in each sketch
   • Refer to comments in the code for wiring details

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📊 Pin Configurations

Distance Sensor:

• Trigger Pin: 9
• Echo Pin: 10
• DHT11: Pin 2
• Buzzer: Pin 4

Hall Sensor:

• Analog Input: A0
• LED Output: Pin 3

Light Sensor:

• LDR Input: A0
• Speaker Output: Pin 11

Temperature Sensor:

• LM35 Input: A0
• Green LED: Pin 2
• Orange LED: Pin 3
• Red LED: Pin 4

Flux Gate:

• Analog Input: A0

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📖 Learning Objectives

• Understanding different sensor technologies and their principles
• Sensor calibration and signal conditioning techniques
• Real-time data acquisition and processing
• Environmental compensation methods
• Digital signal processing basics
• Embedded system design principles

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🎓 Course Information

• Institution: National Technical University of Athens (NTUA)
• School: Electrical and Computer Engineering (ECE)
• Semester: 8th
• Course: Sensors and Measurement Systems