This document describes a project to develop an automatic engine locking system for vehicles using a microcontroller to prevent drunken driving. It includes an alcohol detection sensor, AT89S52 microcontroller, power supply, buzzer, LCD display, motors, and other components. The system is intended to automatically detect if a driver has consumed alcohol and lock the engine if so. It aims to increase road safety by preventing accidents caused by drunken driving. Future enhancements could include GSM and GPS technologies to notify others of alcohol detection and track the vehicle's location.

1. B.Vineetha (11RQ1A0486)
G.Vaishnavi (11RQ1A0484)
M.Mounika (11RQ1A0439)
B.Soujanya (11RQ1A0468)

2. Contents:
 Aim
 Introduction to embedded systems
 Introduction for microcontroller based automatic engine locking system for
drunken drivers
 Block diagram of project
 Power supply
 Microcontroller
 Alcohol detection sensor
 Buzzer driver circuit
 Transformer
 LCD
 Motors
 LM324 op-amp
 Advantages
 Applications
 Future enhancement
 Conclusion

3. Aim:
The main purpose behind this project is “Drunken
driving detection”. Now-a-days, many accidents are
happening because of the alcohol consumption of the
driver. Thus drunk driving is a major reason of accidents
in almost all countries all over the world.

4. Introduction to Embedded systems:
 An embedded system is one that has computer-hardware with
software embedded in it as one of its most important component. It is
a dedicated computer-based system for an application(s) or product.
 An embedded system has three main components.
1. It has hardware
2. It has main application software.
3. It has a real time operating system (RTOS)

5.  An embedded system has software designed to keep in view three
constraints:
(i) Available system memory.
(ii) Available processor speed.
(iii) The need to limit power dissipation when running the system
continuously.

6. Introduction to Microcontroller based
automatic engine locking system for drunken
drivers
 Most of these days, we hear lot of accidents due to drunken driving.
Drunken drivers will not be in stable condition and so the rash driving is the
inconvenience for other road users and also question of life and death for the
drunken driver and for others.
 The system uses a compact circuitry built around Flash version of
AT89S52 microcontroller with a non-volatile memory capable of retaining the
password data for over ten years. Programs are developed in embedded C. ISP
is used to dump the code into the microcontroller.

7. Block diagram:
Alcohol
Detection
sensors
AT89S52
Micro
Controller
Buzzer
LM324
Power
supply
Motors

8. Power supply:
 The above process is needed for the conversion of AC to
DC using rectifier and then ripples are removed using
filter circuit(capacitor).
 Here we use 7805 voltage regulator.

9. Micro controller:
Fig: 8051 microcontroller pin diagram

10. Alcohol detection sensor:
 The alcohol detection sensor used in our project is MQ-3 sensor.
Fig: MQ-3 alcohol detection sensor

11. Buzzer driver circuit:
 Microcontroller pins are not sufficient to drive circuits like relays and buzzers.
 So we use driver circuit in between microcontroller and buzzer.
 This complete structure is known as buzzer driver circuit.
AT89S52
Micro
Controller
Driver
circuit
Buzzer
Fig: Buzzer driver circuit

12. TRANSFORMER:

13. LCD:
LCD (Liquid Crystal Display) screen is an electronic
display module and find a wide range of applications.
A 16x2 LCD display is very basic module and is very
commonly used in various devices and circuits. A
16x2 LCD means it can display 16 characters per line
and there are 2 such lines.
Fig: LCD pin diagram

14. Motors:
 Here we use DC motors.
 The speed of a DC motor is directly proportional to the supply voltage.
 If we reduce the supply voltage from 12 Volts to 6 Volts, the motor will run at
half the speed.

15. LM324 op-amp:
 The LM324 series are low-cost, quad op-amps with true differential inputs.
 They have several distinct advantages over standard operational amplifiers.
 Single Supply Operation: 3.0 V to 32 V (LM224, LM324, LM324A).
 Low Input Bias Currents: 100 nA Maximum (LM324A).
 Four Amplifiers Per Package.

16. •Low cost.
•Automated operation.
•Low Power consumption.
•It provides an automatic safety system for cars and other
vehicles as well.

17. •“Alcohol Detector project” can be used in the various vehicles for
detecting whether the driver has consumed alcohol or not.
•This project can also be used in various companies or organization to
detect alcohol consumption of employees.

18. Future enhancement:
 We can implement GSM technology to inform the relatives or
owners of the vehicle about the alcohol consumption.
 We can implement GPS technology to find out the location of
the vehicle.

19. In this project we have developed a real time model
that can automatically lock the engine when a drunken
driver tries to drive a car. Now-a-days car accidents are
mostly seen. By fitting this alcohol sensor into the car,
we can save guard the life of the driver and also the
remaining passengers.

20. References:
 Embedded systems
 Microcontroller AT89S52
 www.wikipedia.org
 www.atmel.com
 Passive Alcohol Sensors Tested in 3 States of Youth Alcohol
Enforcement-NHSA(1996)

22. QUERIES..?