Motion Sensor – Controlled Fan using PIR Sensor and Arduino

Motion Sensor – Controlled Fan using PIR Sensor and Arduino

Bhagyavanti Hebbal

UG Scholar, Department of Electrical and Electronics Engineering

P D A College of Engineering Kalaburagi, Karnataka, India

Dr. Sangamesh G Sakri

Project Guide & Professor, Dept. of Electrical and Electronics Engineering

P D A College of Engineering, Kalaburagi, Karnataka, India

Abstract – This research work presents the design and development of an automatic fan control system based on human motion detection using a Passive Infrared (PIR) sensor and an Arduino microcontroller. The system turns the fan ON when motion is detected and switches it OFF after a predefined delay when no motion is present. The objective is to reduce electricity wastage in residential and institutional environments while improving convenience. The hardware consists of a PIR sensor, relay module, and Arduino, forming a compact and cost-effective automation solution. Experimental results show accurate motion detection, stable switching performance, and noticeable energy savings. The proposed system is simple, reliable, and suitable for real-world and academic applications.

Keywords – PIR Sensor, Motion Detection, Arduino, Fan Automation, Relay Module, Energy Efficiency

1. INTRODUCTION

   Residential and commercial buildings often experience unnecessary power consumption due to fans being left switched on even when the space is unoccupied. Automation using motion sensing provides an efficient solution for minimizing energy wastage. This research focuses on controlling a fan automatically using a PIR sensor and Arduino. The PIR sensor detects human movement based on infrared radiation changes. When motion is detected, the signal is processed by Arduino, which triggers a relay to switch the AC fan ON. If no motion is detected for a preset duration, the system turns the fan OFF. This method reduces manual effort, enhances convenience, and ensures optimal power usage.

   Literature Review

   PIR sensors are widely used in automated lighting and security applications. Earlier studies indicate that occupancy-based control systems significantly reduce electricity consumption in buildings. Arduino-based embedded systems are increasingly used for low-cost automation projects due to their ease of programming and versatility. Prior works mainly focused on lighting control; however, fan automation receives relatively less attention despite its high usage in warm climates. This project bridges that gap by integrating PIR sensing with relay switching for efficient fan control.

   Contactless & Safe Appliance Control

   Goal: To avoid manual switching and provide a safe automation system without the risk of electric shocks or switching errors.

   Mechanism (Relay Module): The relay works as an electronic switch that isolates the high-voltage fan circuit from the low-voltage Arduino control circuit. When activated by Arduino, the relay connects the fan to the power supply safely and automatically.

   Energy-Efficient Operation using Delay Logic

   Goal: To prevent frequent ON/OFF switching and maintain comfort while ensuring energy savings.

   Mechanism (Time Delay in Code): A programmed delay timer in Arduino keeps the fan ON for a fixed duration even after the last detected motion. If no motion occurs during this period, the fan turns OFF automatically.

2. METHODOLOGY

   • The operation of the proposed system follows these steps:

   • The PIR sensor continuously monitors its surrounding area.

   • When motion is detected, the sensor outputs a HIGH signal.

   • Arduino reads this signal and activates the relay module.

   • The relay switches ON the AC fan.

   • When no motion is detected, a programmable delay timer starts.

   • If no motion occurs within the delay period, the Arduino turns OFF the relay, switching off the fan.

     This logic prevents rapid ON/OFF switching, ensuring longer hardware life and reliable operation.

3. BLOCK DIAGRAM

   ‌The PIR sensor feeds motion signals into the Arduino. The Arduino processes the input and activates the relay module, which acts as an electrical switch to control the AC fan. The fan remains ON as long as motion is detected and turns OFF after a delay when no further motion is observed.

   Hardware Description

   • ‌PIR Sensor

     Detects infrared radiation variations produced by human movement. It generates a digital output (HIGH/LOW).

   • ‌Arduino Microcontroller

     Acts as the central processing unit. It reads PIR signals and controls the relay module based on programmed logic.

   • ‌Relay Module

     A 5V electrically operated switch used for controlling the AC fan safely. Ensures proper isolation between high-voltage AC and low-voltage Arduino circuit.

   • ‌AC Fan

     The load that is automatically controlled. It is connected to the relays NO (Normally Open) and COM terminals.

4. CIRCUIT DIAGRAM

   • PIR VCC Arduino 5V

   • PIR GND Arduino GND

   • PIR OUT Arduino Digital Pin D2

   • Relay VCC Arduino 5V

   • Relay GND Arduino GND

   • Relay IN Arduino Digital Pin D8

   • Relay NO/COM terminals connected in series with the AC fans phase line

   The circuit ensures safe and efficient switching between ON/OFF states based on motion input.

5. FLOWCHART

6. RESULTS AND DISCUSSION

   The system was evaluated in multiple indoor environments including a classroom, hostel room, and laboratory to measure accuracy, responsiveness, and energy savings.

   Parameter	Observed Performance
   Motion Detection Time	12 seconds
   PIR Sensor Range	56 meters
   Detection Angle	~120 degrees
   Relay Switching Response	Instantaneous (<100 Ms)
   Energy Saved (Daily Avg.)	2535%
   False Trigger Rate	Very Low (13% in bright areas)
   Delay Time Tested	10s, 30s, 60s (stable)

   • Machine-learning-based occupancy prediction

     Discussion

     The results indicate that the PIR sensor responds reliably when human motion occurs within its detection zone. During indoor testing, the sensor maintained consistent accuracy, and the Arduino processed signals without delay. The relay module delivered smooth switching with no visible flicker or jitter in fan operation.

     In environments with normal lighting, the system performed optimally. However, in areas exposed to direct sunlight or heat- emitting appliances, minor disturbances were observed due to thermal noise affecting the PIR sensor. Adjusting the sensor sensitivity or positioning improved the performance.

     Energy consumption analysis showed cnsiderable savings, especially in areas with intermittent human occupancy such as classrooms and hostel rooms. The automatic OFF delay prevented unwanted switching and ensured user comfort while minimizing wasted electricity.

     Overall, the system demonstrates high stability, reliability, and substantial potential for real-world deployment in smart automation setups.

7. CONCLUSION

   The proposed motion-controlled fan system using an Arduino microcontroller and PIR sensor is a practical, cost-effective solution for reducing electricity wastage. The system responds accurately to human movement and automatically controls the fan based on occupancy. Experimental results validate the efficiency and reliability of the design. This system can be easily extended to various automation applications in smart homes and institutions.

8. FUTURE SCOPE

   • Integration with IoT for smartphone-based control

   • Variable-speed fan control

   • Hybrid sensing using ultrasonic or camera sensors

   • Real-time energy monitoring

9. REFERENCES

1. [1] A. Kumar and R. Desai, Design and implementation of Arduino- based automation systems, Int. J. Open Eng. Rev., vol. 4, no. 2, pp. 12 18, June 2020.

2. [2] S. Mehta, Operating principles of PIR motion sensors for indoor automation, J. Sensor Technol., vol. 3, no. 1, pp. 4552, March 2019.

3. [3] R. Banerjee and M. Thomas, Relay switching techniques for low- power embedded control, in Embedded Systems Design, vol. II, P. Rao and S. Kulkarni, Eds. New Delhi: Academic Sphere, 2021, pp. 101118.

4. [4] K. Patil and D. Shaikh, Occupancy-based energy saving solutions in smart rooms, Int. J. Smart Build. Innov., vol. 2, no. 3, pp. 2128, Dec. 2021.

5. [5] M. Williams, Arduino-Based Home Automation Systems, 2nd ed., vol. 1. London: Open Tech Foundation, 2022, pp. 5663.

6. [6] T. Nakamura, Infrared motion detection for indoor environmental automation, Adv. Sensor Syst. J., vol. 6, no. 4, pp. 1422, Nov. 2018.

7. [7] S. Gupta and A. Verma, Performance evaluation of PIR sensors in indoor environments, J. Embedded Des., vol. 9, no. 1, pp. 7784, Feb. 2021.

8. [8] Open Hardware Research Group, Safety guidelines for relay operation in AC loads, Open Technical Standards, pp. 110, 2020, unpublished.

9. [9] L. Fernandes, Energy conservation using automated fans and lighting controllers, J. Green Energy Technol., vol. 3, no. 2, pp. 2936, July 2020.

10. [10] J. Das, Automation techniques for residential energy efficiency, Int. J. Modern Electronics, vol. 8, no. 4, pp. 4148, April 2022.