TECHNICAL DETAILS

CPU: Central processing unit is the brain of AUTO MODE METRO TRAIN. It processes all inputs and gives corresponding outputs.

KEYPAD: Keypad is use to input password (0-9 digit) into microcontroller. Three switches are uses for function switches.

SEVEN SEGMENT: Seven-segment display is use to show inputted digits from keypad.

OPEN/CLOSE SWITCHES: NPN transistor is use to opening and closing of lock.

ADVANTAGES 

1. It uses low cost microcontroller.

2. very simple to use.

3. long length password.

4. low power consumption.

FURTHER MODIFICATION

In future, security system can be in-built with this lock like:

1. Wrong password input alarm.
2. Finger print sensor.
3. IR detector for theft.