Railway-Crossing Indicator(regarding to state machine)

[kingsleyloo]

Guys,im a newbie of electronic student. I need all of u to help me have a look about my this design question since i really cant find any clearer example to refer><(my lecturer told that it's actually related to state machine..=_=)


The intersection junction of a railway and a road. The flashing light and warning bell are to be turned on when a train enters Area 2 either from Area 1 or Area 3; and turn off when a train leaves the intersection. The flashing light and warning bell will turn on for 5 seconds and 3 seconds respectively. Three signals P1, P2 and P3 are generated when a train is in Area 1, 2 and 3 respectively.

Design a railway-crossing indicator that meets the design specification above.

Hints:

(a) Your circuit should have 5 outputs, 3 signals for Area 1, Area 2 and Area 3. Use LEDs to simulate as outputs.
(b) The railway-crossing indicator has 4 states: No train approaching, Train approaching, Train at intersection junction and Train left the intersection junction.
(c) Use counters to keep track of time for the flashing light and warning bell signals.
(d) Use LEDs to simulate P1, P2 and P3 signals.
(e) Use switches to simulate the presence of train in respective area.


Can anyone give me any information or suggestion about this design? thanks a lot

 

[angie1199]

Take a look at **broken link removed**.

It has the lights and gates switched. You should be able to use the gates option for a bell instead.

Angie

 

[Mikebits]

Take a look at **broken link removed**.

It has the lights and gates switched. You should be able to use the gates option for a bell instead.

Angie

The assignment specifies a state machine which implies sequential logic.

 

[kingsleyloo]

Angie,thanks for ur link

Mike:ya,it's related to sequantial detector(state machine). So,do you have any idea or suggestion about it?

 

[Mikebits]

Angie,thanks for ur link

Mike:ya,it's related to sequantial detector(state machine). So,do you have any idea or suggestion about it?

Your first step should be to draw out your state diagram. Once you have that, then you can figure out how to proceed.
Qfsm - Homepage

 

[kingsleyloo]

Your first step should be to draw out your state diagram. Once you have that, then you can figure out how to proceed.
Qfsm - Homepage

this is the figure n my state diagram below. my major problem is that i don't know how to use LEDs and counters to present the thing out. i unable to link the LEDs and counters with this question. sorry to dissapoint u=_="

**broken link removed**[/URL][/IMG]