Digital Elevator Simulation

Thread Starter


Joined Nov 8, 2006
I need some help designing a Digital elevator simulation using multimedia logics.I need some help and guidelines as to how I should get the truth table , kmaps and the digital circuit. I am required to use priority encoder, D lache and led drivers

I am required to design a digital circuit which has applications in elevator style controls. My circuit will be able to accept 4 momentary closed switches (push buttons) as input, for selecting one of four levels (i.e. 0, 1, 2 & 3). The output of the circuit will be the value of the presently selected level on a seven (7) segment LCD display. Additionally, my circuit should light one of four (4) LEDs corresponding to the push button which is activated. The circuit must maintain the state of all outputs even after a push button is released; only changing state when another button is activated. The circuit should be robust enough to cater for the possibility of several buttons being simultaneously activated by only registering the highest level of those selected.
Sounds like a state machine using discrete logic. I am not sure what you have in mind for a priority encoder but it may have features that you may need to use. Otherwise, the next step is to do a state diagram indicating the conditions required to change states from one to the other. Also, what will you use for an LED driver? There are many choices, depending on the family of components you want to use. For instance you could use something from the 7400 series for 5 VDC supply voltage or CMOS (3 to 15 volts DC). Do you have any more details on the requirements? It could affect the design choices.


Joined Sep 13, 2007
hi all.

i have a similliar situation here.i need to design a elevator switch board circuit.i have some momentary switches.i need the momentary switches to continuosly activate the corresponding led even after coming back to open position.can anyone pls email is


Joined Apr 27, 2007
I'm repeating myself here, but you should not expect other users to make circuits for you from root. It is your work.
Nevertheless, it is my pleasure to help you, but you have to present some more base ideas. For example, do you prefer discrete components or microcontrollers? What are the requirements? Give more detail, please.


Joined Dec 7, 2007
It seems that we have the same project. I have some more complicated situations but basically the important parts are the same. I am using the 74L series. Untill now i have made the trouth table and the K map. I also used the DeMorgan technique, in order to make my circuit exclusive by NAND gates. I putted the 7LED display with a decoder, and this is how I display the floor. I have also putted some LED's to show if the elevator moves. But here comes my problem. I am supposed to put 3 LED's per floor to show if the elevator moves(up & down) or stays still. The problem is that I cannot understand how I am going to make the elevator go down or up, and especially who can I make each LED turn on in every situation.
I hope that i gave you some ideas. If anyone alse can help me it would be fine because I have only 2 weeks to finish my project and I am in a really hurry!


Joined Apr 20, 2004
Use a counter to sumulate the motion of the elevator. Make it an up/down counter. Clock to count up to simulate the car going up. Let the LED's track the count to indicate motion up or down.


Joined Dec 7, 2007
I have come to a good level but there are still some problems. The biggest problem is that the elevator is not automated and i have to set by my own if it goes up or down. I choose the floor and set up or down to go there. This is the first problem. I have also problems making the campine and the floors working together. It is supposed that when i choose the floor (inside the elevator) the Led on its floor is lighting, but at the end i have to set "on" the Leds by my own. I read the post that told me to use the counter, but the trouth is that i have not been teached the counters and how we use them.
There are only 2 days left, until the day that i have to give my project!!! I will try to do my best, even if that thing will not work 100%!!! Hope that the teacher will understand....:rolleyes: