# Help me! -- How to design an elevator pad/display in which a user enters a floor number

Discussion in 'Homework Help' started by Batoul_5, Dec 30, 2015.

1. ### Batoul_5 Thread Starter New Member

Dec 30, 2015
5
0
Hello everyone,

I have a project on digital logic design, and please I need help.

How to design an elevator pad/display in which a user enters a floor number, and the display shows the floor numbers in sequence (whether going up or going down). Using the logic gates, FSM, etc.

If you have any idea how can I do it please let me know,
Thank you all.

2. ### atferrari AAC Fanatic!

Jan 6, 2004
2,647
759
Hola Batoul

If your elevator cover, say 8 floors, you would need 14 buttons, 7 to go up and 7 to go down. (Hope you understand why).

Once this is clear for you, decide on how you will read them. I presume that you will be using a micro to do it in sequence (that is the secret) thus no clash between two buttons being pushed down at the same time.

Another point: you do it continuously, all the time.

Based on that, now start your design.

3. ### Veracohr Well-Known Member

Jan 3, 2011
550
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Why on earth would you need 14 buttons for 8 floors? What elevator have you been on like that?

Batoul, try starting with drawing out a state machine diagram that does what you need. Then figure out the gates needed.

4. ### atferrari AAC Fanatic!

Jan 6, 2004
2,647
759
With the exception of first and last floor you need two to require UP or DOWN.

5. ### atferrari AAC Fanatic!

Jan 6, 2004
2,647
759
My bad, I was thinking on the pads for each floor. The OP is going to save a lot of buttons. Good.

6. ### n1ist Active Member

Mar 8, 2009
171
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Sounds like he is designing the panel inside the cab... Do a search here; elevator questions come up a few times every year...
/mike

7. ### hp1729 Well-Known Member

Nov 23, 2015
1,944
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Are you talking about a familiar 12-key pad and display as opposed to an array of buttons, one for each floor, like we find in elevators? A similar pad and display on each floor so you request a floor not just call an elevator?
jI can see the value of this in large buildings.