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1.1 INTRODUCTION:
Metro Train was first introduced in Kolkata in India . Metro Train facilitates transportation within the city limits. It is only for the transportation from one place to another place in a city, not from one city to another. It is faster than an ordinary train, so people can reach their destination soon. It avoids traffic jam in the city as it is always below the ground level or above the ground level. It avoids accidents occurring in the city due to heavy traffic. More people can travel in metro train. It can carry hundreds of people at a time. It saves fuel for future use. People traveling in their own vehicles can also afford to travel in metro train. It has announcement system for announcing the station names through which the passengers can get to know their destination which is not available in buses and auto. Also buzzer will make a beep sound to indicate the train is stopped or train is leaving. It also displays the station name. It avoids pollution.
Initially it may involve more investments but later the output got will be worth of the investment made. For a well planned city it is easy to plan for metro train whereas for a city which is not well planned it is very difficult. It requires more initial steps before it is started like survey of soil, digging the soil to examine, etc. Many problems like destroying of properties for widening the road will occur which will affect those people who are well settled.
Metro train is yet to be introduced in our Garden City BANGALORE. It is also approved by the government. Initial works have been started. Within few years even Bangalore will have metro train facility.
1.2 Functional Description of the Project:
The main aim of this project is to make an automated place announcement system for Train using voice IC and the radio frequency wireless card for tracking the station data. In buses and train there are no facilities like automated place announcement system or display system, so it is very difficult and inconvenient for the passengers to know the respective area they are in at present especially to those who are new to the place. So this project is designed in such a way that, it will announce the place names automatically by sensing the RF signals transmitted from each bus stop or the railway station. In our project the PCB and the CIRCUIT diagram is designed using Express PCB software.
1.3 Working Principle of metro train:
The flow chart shown in figure 1 explains the working principle of the metro train. The project consists of microcontroller with the RF receiver and the voice recorder chip with speaker .The whole system is attached to the vehicle (BUS or Train). When the project is powered the train moves, until it encounters a RF card placed beneath the track. The encoded RF transmitters are placed in the BUS stops or the railway stations. The microcontroller in the TRAIN is programmed in such a way that every station name saved in the voice chip which is having a unique code. So whenever the bus or train reaches the station, the receiver in the bus or in the train receives the codes, which are transmitted form the transmitter and the microcontroller receives this code and checks in the look up table, saved in the chip. Which ever matches, the controller will send the command to the voice chip to play that particular voice, the announcement can be done for 6 seconds with the station number and the place. At the same time the train stops for about 10 seconds in the station and then before leaving the station, it will again start to announce “THE TRAIN IS LEAVING” and the train starts to move to next station. The voice chip will play the voice and this will be heard in the speaker. This voice is repeated till the train leaves the station. In this module LCD is used for the
display purpose, in the programming what we have stored it will be displayed in the LCD. For E.g.: station number will be displayed when the train reaches the station, even when the train is leaving it will display on the LCD even it will announce it using the IC chip, the train is in which station and when it is leaving also. Buzzer is used in this module; it will give beep sound when the train reaches a station and when it is leaving station every time.
Another feature added to this project is:
• The change of RF card numbers through serial port.
• Voice recording by changing the jumper position in the module.
The above figure shows the block diagram of the metro train. 8051 being the main IC controls all the operations. The LCD, buzzer, voice chip and RF card reader are interfaced to this IC. The components which are interfaced are explained below:
Voltage Regulator (LM 7805):
Figure 3 shows the block diagram of voltage regulator. The LM78XX series of three terminal positive regulators are available in the TO-220 package and with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 1A output current. Although designed primarily as fixed voltage regulators, these devices can be used with external components to obtain adjustable voltages and currents.
Features:
• Output Current up to 1A.
• Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24.
• Thermal Overload Protection.
• Short Circuit Protection.
• Output Transistor Safe Operating Area Protection.
The micro controller and other devices get power supply from AC to DC adapter through voltage regulator as shown in figure 4. The adapter output voltage will be 12V DC non regulated. The 7805 voltage regulators are used to convert 12 V to 5VDC.
LCD 16x2:

Liquid crystal displays (LCDs) offer several advantages over traditional cathode-ray tube displays that make them ideal for several applications. Of course, LCDs are flat and they use only a fraction of the power required by cathode-ray tubes.
They are easier to read and more pleasant to work with for long periods of time than most ordinary video monitors. There are several tradeoffs as well, such as limited view angle, brightness, and contrast, not to mention high manufacturing cost.
16x2 LCD which is shown in figure 5 is used in this project to display data to user. There are two rows and 16 columns. It is possible to display 16 characters on each of the 2 rows. It has two registers, command register and data register.
LCDs can add a lot to your application in terms of providing an useful interface for the user, debugging an application or just giving it a "professional" look. The most common type of LCD controller is the Hitachi 44780 which provides a relatively simple interface between a processor and an LCD. Using this interface is often not attempted by inexperienced designers and programmers because it is difficult to find good documentation on the interface, initializing the interface can be a problem and the displays themselves are expensive.