ABSTRACT:

Railways, being the cheapest mode of transportation are preferred over all the other means. When we go through the daily news papers, we come across many railway accidents occurring at unmanned railway crossings. This is mainly due to the carelessness in manual operations or lack of workers. In order to overcome these dangerous problems we in this project came up with a solution for the same. Using simple electronic components and a wireless communication technique we have tried to automate the control of railway gates. The main aim of this project is automating the unmanned railway gate i.e. the gate is closed automatically whenever the train arrives and gate is opened after the train leaves the railway-road crossing. AT89C51 microcontroller is the heart of the circuit as it controls all the functions. Here in this project, the railway gate will be controlled by using wireless communication from a remote place through PC. The wireless communication between the remote areas will be achieved by using the RF modules called RF transmitter along with an RF encoder and RF receiver along with an RF decoder. The project is designed in such a way that the microcontroller will be interfaced to the PC through serial communication which is a supportable feature of 8051 microcontroller, on the transmitter side i.e. at the controlling unit. Here two keys on the keyboard will be dedicated for controlling the gate i.e. to open and close the gate. The microcontroller and PC will get interfaced via a serial line driver IC MAX232 . And for the visual effects, the front end will also be developed by using a good user interface software VB .NET to input the data to the controller through serial communication.  And the controller will also be interfaced to the RF transmitter through RF encoder to encode the data received by the controller and to transmit the signal. The controller will be programmed in such a way that, whenever the predefined data receives by the controller from PC, it sends corresponding signals to the RF encoder which encodes the data and passes it to the transmitter, so that the data will be transmitted. The transmitted data will be received by the receiver which will be interfaced to the controller through an RF decoder, on the receiver side. The receiver unit will be fixed to the railway gate. The decoder is used to decode the encoded data into 4 bit digital data and will pass it to the controller. Now the controller performs the predefined task of closing or opening the gate. We interface a DC motor the controller through a driver IC L293D to control the movements of gate. Here the liquid crystal display makes the system user friendly by displaying the status of  gate.             This project uses regulated 5V, 500mA power supply. Unregulated 12V DC is used for relay. 7805 three terminal voltage regulator is used for voltage regulation. Full wave bridge rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.

TECHNICAL SPECIFICATIONS:

HARDWARE:

Micro controller         :           AT89S52

Crystal                        :           11.0592 MHz

LCD                            :           HD44780

RF transmitter             :           STT-433MHZ

RF receiver                 :           STT-433MHZ

RF encoder                 :           HT12E

RF decoder                 :           HT12D

DC motor                    :          

Driver IC                     :           L293D

Power supply

Transformer                :           12V step down 

Filter                           :           1000uf/25V

Voltage Regulator      :           7805

SOFTWARE :

Keil microvision