BTech Electronics & Communication Engineering Project for Embedded Systems on Temperature Controlled Fan using ATMega8 Controller and LM35 Temperature Sensor.

1. EMBEDDED SYSTEMS
PROJECT PROPOSAL

2. TEMPERATURE CONTROLLED
FAN USING
MICROCONTROLLER

3. Introduction

4. The proposed system i.e. temperature controlled fan
using microcontroller will be used to control the
speed of the fan according to the temperature and
specify the temperature in the display.
AIM

5. • Domain: Embedded Systems
• Application Area: Automation
• Purpose of Work: Conversion of a manual fan to
an automatic speed controlled fan according to the
temperature

6. Required Tools
&
Literature Review

7. Required Components
• ATmega8
• Temperature sensor (LM35)
• L293D motor driver
• Crystal Oscillator
• DC motor/fan
• LCD
• Power supply

8. Temperature Sensor: LM35
The o/p of this temperature sensor is linearly proportional to the Celsius scale.
This IC doesn’t need any external calibration to give accuracies.
The main function of the temperature sensor in the proposed system is to
detect the temperature of external environment of fan.

9. ATmega8
ATmega8 microcontroller has 23 programmable input/output (I/O) pins which can be used
for interfacing with external world. It is possible to configure them as input or output by
setting a particular register value through programming. This IC comes in 3 different
packages, but we are using the popular 28-Pin PDIP package (Atmega8-16PU). The 23
I/O ports of ATmega8 are organised into 3 groups: Port B (PB0 to PB7) Port C (PC0 to
PC6) Port D (PD0 to PD7).

10. ATmega8
Circuit Design

11. Crystal Oscillator
A crystal oscillator is an oscillator circuit, which uses the mechanical
resonance of a vibrating to create an electrical signal with a very precise
frequency.
The crystal oscillator is used in the system to provide clock signal to the
microcontroller

12. L293D
L293D is a 16 pin IC, with eight pins, on each side, dedicated to the
controlling of a motor. There are 2 INPUT pins, 2 OUTPUT pins and 1
ENABLE pin for each motor.

13. Properties of Temperature Controlled Fan
• When the temperature surpasses 35 ᵒ C then fan should run at max
speed.
• When the temperature drops below 15 ᵒ C then fan should be at min
speed.
• The fan speed should change according to the range of temperature
from 15 ᵒ C to 35 ᵒC,

14. Expected Results
&
Future Scope

15. • Replace the manually operated fans by automatic temperature
sensor fans
• The applications of the temperature controlled fan includes where
the consumption of power has to be controlled such as firms,
institutes, organizations, home appliance, in computers to cool
the processor.
• Furthermore this project can be enhanced by interfacing it with
air conditioners.

16. References

17. • www.elprocus.com
• www.engineersgarage.com

18. SUMMARY

19. THE
END
Prepared By:-
Aditya Ratnaparkhi
Chaitanya Pawa
Rajat Dhawan
Shivam Chhabra