in project i m really confused what to do to identify different kinds of traiins to know which train has passed? after that i have to give signal to other leds either red or green. so please give me solution. after this we will update database and allow the train to pass which has higher priority and stop train with lower priority.

 

In the real world this has been done with barcodes among other schemes. This lets you even track the cars.

Regards
cww

 

with out a full inter grated system with data base allowing some sort of cataloguing and tracking this would come to be very difficult a number system trains with a number 1 in there first tracking id number are given the highest rank the code written for the sub controllers would need to work with this same type of idea there may be many controllers in the system and a
network would need to over see the communications it is not answerable in five or less lines good luck ---

 

Have you thought of utilising RFID.

This would avoid contamination of barcodes by dirt, and enable complete asset tracking of the train carriages.

Derrick Stableford

 

RFID is probably the most robust solution. There are many RFID integrating companies out there. A simple Google search will find many.