FSM - Can someone help me to solve this?

[Helpmeout]

1. The circuit uses three LEDs for the output (must be different colors, preferably red, yellow, and
green, to match a real light), and has three inputs.
2. At circuit power-on, normal ‘day’ operation commences:
a. Only the red LED is on for two seconds.
b. Then only the green LED is on for two seconds.
c. This is followed by the yellow LED which is on for one second. The cycle then repeats
indefinitely (until a pedestrian presses a switch), starting with red.
d. If a pedestrian presses a switch, the green light should transition to yellow (in 1 s) and
then to red (in 1 s) and remain red for 6 seconds before resuming the typical sequence.
3. At ‘night’ (triggered by light sensor), a special mode of operation commences:
a. Once the green LED is on, it remains on indefinitely until the presence of cross traffic is
detected by placing an object in front of the IR sensor (this sensor does not affect during
‘day‘). If cross-traffic is detected, then ‘day‘ operation resumes until the IR sensor
detects nothing.
b. ‘Night‘ mode ends and ‘day‘ mode resumes when the light sensor detects the presence
of strong light.

 

[Martaine2005]

Your state machine will require a micro controller.
It’s obviously a traffic light or pedestrian light crossing.
Using a counter IC, you could achieve the 2 second and 1 second intervals by jumping outputs.

what have you done so far to map this out?

Martin

 

[Helpmeout]

Yes I am looking to use decade counter but can I implement this without micro controller. Just by using 555 timer and Decade counter? It is really hard for me to work out on state diagram. I dont know where to start for this state diagram since it got more states.

Your state machine will require a micro controller.
It’s obviously a traffic light or pedestrian light crossing.
Using a counter IC, you could achieve the 2 second and 1 second intervals by jumping outputs.

what have you done so far to map this out?

Martin

 

[AnalogKid]

Anything can be done with logic gates and state machines if you are patient and careful. As this is homework, you don't get free answers, but here is some guidance ...

Because there are so many differences between day mode and night mode, and day mode is an internal component of night mode, consider one state machine for day mode, and an overall controlling state machine to handle the differences for night operation.

ak

 

[Helpmeout]

Anything can be done with logic gates and state machines if you are patient and careful. As this is homework, you don't get free answers, but here is some guidance ...

Because there are so many differences between day mode and night mode, and day mode is an internal component of night mode, consider one state machine for day mode, and an overall controlling state machine to handle the differences for night operation.

ak

Thanks for the reply I am have created a state diagram but however, I don't know whether it is correct because I am trying to create a state diagram including all the scenario including push button and Day & night condition