This document describes a microcontroller-based project to control traffic and regulate vehicle speeds. The system divides a city into zones and sets different speed limits for each zone based on traffic levels. Sensors detect when a vehicle enters a zone and the microcontroller varies the vehicle's speed based on the zone's limit. Information is displayed on LCD screens and data is transmitted between zones using RF modules. The system uses a power supply, rectifier, regulator, and other components to function properly. It aims to improve road safety by automatically enforcing variable speed limits tailored to each traffic zone.

2. Introduction
 Embedded systems are designed to do some specific
task, rather than be a general-purpose computer for
multiple tasks.
 An embedded system is not always a separate block -
very often it is physically built-in to the device it is
controlling.

3. Description to project
 The purpose of the project is to control the traffic problem
presently observed in cities.
 where due to large population and inadequate infrastructure,
road safety enforcement and traffic regulation is very difficult.
 The speed of the vehicle can be varied by varying the “duty
cycle” of the pulse input.
 This project uses regulated 5V, 500MA power supply, 7805
three terminal voltage regulator is used for voltage regulation.
 Bridge type full wave rectifier is used to rectify the ac output
of secondary of 230/12V step down transformer.

4. Block diagrams
Zone section:
POWER SUPPLY LCD DISPLAY
(16 X 2 LINES)
IR1 TX IR1 RX
ENTRY ENTRY MICRO
CONTROLLER
IR1 TX IR1 RX ENCODER
AT89S52
EXIT EXIT
IR2 TX IR2 RX
ENTRY ENTRY RF TX
IR2 TX IR2 RX
EXIT EXIT

5. Vehicle section:
LCD DISPLAY
BATTERY
(16 X 2 LINES)
MICRO
CONTROLLER
DECODER MOTOR
AT89S52 DRIVER
RF RX
MOTORS

6. BLOCK DIAGRAM EXPLANATION
Micro controller:
 In this project work the micro-controller is plays major
role.
 Micro-controllers were originally used as components in
complicated process-control systems.
 Micro-controllers are small in size and less cost.
 One of the major differences between a Microprocessor
and a Micro controller is that a controller often deals with
bits not bytes as in the real world application.

7. RF transmitter section
 RF transmitters are electronic devices that create
continuously varying electric current, encode sine waves,
and broadcast radio waves.
 Modulators encode these sign wives and antennas
broadcast them as radio signals.
 Radio techniques limit localized interference and noise.
 Additional considerations when selecting RF transmitters
include supply voltage, supply current, RF connectors,
special features, and packaging.

8. RF TRANSMITTER
Pin Description of the Transmitter
module

9. Flow chat for data transmission in
HT12E

10. RF receiver section
 RF receivers are electronic devices that separate radio
signals from one another and convert specific signals into
audio, video, or data formats.
 RF receivers use an antenna to receive transmitted radio
signals and a tuner to separate a specific signal from all of
the other signals that the antenna receives.
 RF receivers vary in terms of performance specifications
such as sensitivity, digital sampling rate, measurement
resolution, operating frequency, and communication
interface.

11. Functional description of RF
receiver module

12. Flow chart of HT12D for data transmission

13. IR-SENSOR
 Infrared (IR) radiation is part of the electromagnetic spectrum,
which includes radio waves, microwaves, visible light, and
ultraviolet light, as well as gamma rays and X-rays.
 A sensor network is a computer network of spatially distributed
devices using sensors to monitor conditions (such as temperature,
sound, vibration, pressure, motion or pollutants) at a variety of
locations
 IR wavelengths are usually expressed in microns, with the lR
spectrum extending from 0.7 to 1000microns.
 Based on the sensor's calibration equation and the target's
emissivity.
 This temperature value can be displayed on the sensor or, in the
case of the smart sensor, converted to a digital output and
displayed on a computer terminal.

14. IR SENSORS

15. MOTOR DRIVER

16. L293D:
 The L293 is an integrated circuit motor driver that can be
used for simultaneous, bi-directional control of two small
motors.
 The L293 is limited to 600 mA, but in reality can only
handle much small currents unless you have done some
serious heat sinking to keep the case temperature down.
 The L293 comes in a standard 16-pin, dual-in line
integrated circuit package. There is an L293 and an
L293D part number.

17. The Pinout for the L293

18. LINEAR KEYPAD
 This section basically consists of a Linear Keypad. Basically a
Keypad can be classified into 2 categories.
 One is Linear Keypad and the other is Matrix keypad.
 Linear Keypad: This Keypad got „n‟ no. of keys connected to
„n‟ data lines of microcontroller.
 This Keypad is used in places where one needs to connect less
no. of keys.
 Here in this project, a linear keypad is used with switches
connected in a serial manner.
 Linear keypad is used in this project because it takes less no.
of port pins.

19. Liquid crystal display
 Liquid crystal displays (LCDs) have materials, which
combine the properties of both liquids and crystals
 An LCD consists of two glass panels, with the liquid
crystal material sand witched in between them.
 The LCD‟s are lightweight with only a few millimeters
thickness. Since the LCD‟s consume less power, they are
compatible with low power electronic circuits, and can be
powered for long durations.
 Changing the display size or the layout size is relatively
simple which makes the LCD‟s more customers friendly.

20. Interfacing of LCD to a micro controller

21. Power supply
 The power supplies are designed to convert high voltage AC
mains electricity to a suitable low voltage supply for electronics
circuits and other devices.

22. Transformer
 A transformer is an electrical device which is used to
convert electrical power from one Electrical circuit to another
without change in frequency.
 A step-down transformer has a large number of turns on its
primary (input) coil which is connected to the high voltage
mains supply, and a small number of turns on its secondary
(output) coil to give a low output voltage.

23. RECTIFIER
 A circuit which is used to convert a.c to dc is known as
RECTIFIER. The process of conversion a.c to d.c is called
“rectification”.
 A bridge rectifier makes use of four diodes in a bridge
arrangement to achieve full-wave rectification.
OPERATION

24. Regulator
 Voltage regulator ICs is available with fixed (typically
5, 12 and 15V) or variable output voltages.
 The maximum current they can pass also rates them.
 Negative voltage regulators are available, mainly for
use in dual supplies.

25. CIRCUIT DISCRIPTION
 The objective of the paper is to present a conceptual model of
a microcontroller based variable electronic speed governor that
can be implemented to control the speed of any vehicle
depending on the local speed limit.
 The circuit is cost effective, efficient and easy to implement on
already existing vehicles.
 Every city, town or a village, can be marked and divided into
individual zones.
 The division depends upon the area under which the business,
residential, and industrial regions come under.
 The central business district being a very busy traffic zone
demands the least speed limit, with the residential and
industrial zones having lesser traffic densities, the speed limits
will vary accordingly.

26. CONCLUSION
 The project “MICRO CONTROLLER BASED
AUTOMATION VARIABLE FREQUENCY ELECTRONIC
SPEED GOVERNOR” has been successfully designed and
tested.
 It has been developed by integrating features of all the
hardware components used.
 Presence of every module has been reasoned out and placed
carefully thus contributing to the best working of the unit.
 Secondly, using highly advanced IC‟s and with the help of
growing technology the project has been successfully
implemented.