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[attachment=7994]

Submitted by:
K.JEEVITHA
(06S21A0420)
S.Y.M.JYOTHI
V.JYOTSNA
J.KOMALI
P.LAKSHMI DIVYAVANI
G.LAKSHMI PRASANNA



Under the Esteemed Guidance of:
K.SUNDAR SRINIVAS


NOVA COLLEGE OF ENGINEERING AND TECHNOLOGY FOR WOMEN


ABSTRACT
Now a day there is a lot of problem with neglecting railway signals by the driver in day today life. The driver may neglect the train signals or it may not be clear due to fog etc that reflects accidents of trains at different places. We have taken the above problem for that we need one solution that solution i.e. developed with automatic speed control of train based on signals developed with microcontroller.Here we have used an Infra Red (IR) transmitter at the signal terminal i.e. continuously transmit the communication code to the receiver based on the signals nature (Red, Yellow and Green). We have established the receiver part in the train that receives communication code transmitted from the transmitter and it gives an alarm in the train subsequently the signal status is displayed on the display (16X2 dot matrix display).
In along with this the speed control of train control system is attached to the microcontroller that reduces the speed of the train when yellow signal is detected, the train stops when red signal is detected, if green is detected the intimation received in the train travels with full speed.
So here we have established asynchronous protocol for transmitting and receiving data’s between signal and train with the help of two microcontrollers. The assembly level program is written in microcontroller for executing entire operation.
In future same system can be connected to Frequency Shift Keying (FSK) for increasing more distance between signals and train.

INTRODUCTION

The speed of the train is regulated by sending signals using LED’s .The signal is received
by the IR LED. Here three LED’s are used at the transmitter side which indicates the color and the type of regulation. The signal is given to the microcontroller which codes the signal. The coded signal is applied to the LED through an Astable Multivibrator.
The signal is received by the IR receiver and is given to the microcontroller at the receiving side. The signals that are then decoded and the appropriate message is send to the liquid crystal display connected to the microcontroller. This means the receiver part in the train that receives communication code transmitted from the transmitter and it gives an alarm in the train In along with this the speed control of train control system is attached to the microcontroller that reduces the speed of the train when yellow signal is detected, the train stops when red signal is detected, if green is detected the intimation received in the train travels with full speed.
Therefore, an asynchronous protocol for transmitting and receiving data’s between signal and train with the help of two microcontrollers. The assembly level program is written in microcontroller for executing entire operation.

TRANSMITTER

In this transmitter part we have used 89c2051 micro controller for the purpose of detecting signals status and transmit appropriate 8bit code to the receiver via IR modulator. Here we have used three LED’s (Red color, Green color, yellow color) to the input port of the micro controller when the signal is at on state the input port comes to bit 0, if the signal is at off state the input port comes to bit 1.
Signaling System:
In the signaling system block these three LED’s are connected via 1K resisters.

RESET LOGIC

The reset logic block provides rest signals to the micro controller. This is constructed with 8.2K resisters and 10µf capacitors.

CRYSTAL OSCILLATORS

This block provides necessary frequency sine wave to the micro controller. This frequency is converted to square wave within the micro controller.

IR MODULATOR

The IR modulator is nothing but an Astable multivibrator generates 35 KHz frequency while receiving bit 0 from the micro controller TXD pin. The frequency

of Astable is decided by R, C connected to the comparator pins of 555. In this module the data is inverted by using one transistor.

IR DRIVER
IR driver is a current cum voltage amplifier (power amplifier) then it increase the input power received from the output of IR modulator.

IR LED
The IR LED is driven by IR driver. It switches at the rate of 35 KHz frequency received from the IR modulator. The IR light is emitted in the free space.

Micro Controller 895C2051

Here we use MC51XX series 20 pin micro controller serves the total operation of transmission. The assembly program written in the micro controller always scans for light and transmits the appropriate 8bit code through asynchronous TXD pin of micro controller in regular intervals.

RECEIVER

Here the IR receiver receives IR frequency from transmitter generates a bit 0 while IR frequency focused on the IR detector, generates bit 1 when there is no IR signal. This IR data is given to the RXD pin of the micro controller used in the receiver.

The Micro Controller

The micro controller receives IR data through RXD pin. The received data is accumulated in serial buffer of 89c52 micro controller. If the data compares with the predefined codes 00H, 01H, 02H. If the code received from IR receiver equals to 00H then the motor will be stopped. If the code equals to 01H we are applying a low voltage
to the motor that rotates with lower speed. If code equals to 02H then the motor rotates with full speed by applying 3 volts, at the same time it gives an alarm indication to the driver and subsequently displays the relevant signal status on the 16X2 dot matrix display attached to the output port of the micro controller.

16X2 Matrix Display
The display is connected to the output port of microcontroller displays the signal information in one or two rows. The details of the display are given in subsequent section.

Buzzer Driver and Buzzer

It is connected to the output port of micro controller. The buzzer is connected via buzzer driver transistor.

The Motor and its Driver

The speed controller regulator is constructed with the two relays operated from two transistors which are connected to the output port of the micro controller. We have a train motors from the output of regulator switch

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