# 7 Segment Display Simulation

#### CPCPCPPcode

Joined Dec 10, 2019
7
I want to design a circuit by logic gates and flip flop. According to the requirement, everytime the button clicked, the segment display between 1, 2, 4, 8 in order. I originally designed one but it's not working, so I am asking for help or hints or discussion, how to implement this segment display simulation.

The left image below is the truth table showing the state and output, the combination of A-G will help achieve displaying number 1,2,4,8; the right one is my attempt to build the circuit but it failed...
Thanks a lot

#### djsfantasi

Joined Apr 11, 2010
5,923
What’s your purpose in designing this circuit?

#### CPCPCPPcode

Joined Dec 10, 2019
7
What’s your purpose in designing this circuit?
For a project, I want to display 1,2,4,8 in order once clicking the button

#### dl324

Joined Mar 30, 2015
9,577
According to the requirement, everytime the button clicked, the segment display between 1, 2, 4, 8 in order.
Can you post the complete text of the problem. It's more typical for a student to be asked to design a counter with a particular count sequence and display the number on a single display (in your case).

#### CPCPCPPcode

Joined Dec 10, 2019
7
This full text of question:
There is a button for you to click, every time you click the button, the FSM will alternate between displaying 1, 2, 4 and 8 in order. In other words, the FSM will display 1—2—4—8–1—2—4—8, if you keep clicking the button. If you don’t click the button, the FSM will keep the current state and not change. In order to accomplish this, the state of the seven segments will be treated as outputs of your FSM. That is, your FSM will output the appropriate state of A, B, C, D, E, F, and G in order to represent the numbers of interest (0 means disabled, and 1 means enabled). For example, if you want to display 0, from the table we know that A, B, C, D, E, F should be enabled while G is disabled, therefore, the output is 1111110 (the state of ABCDEFG). Similarly, if you want to display 1, the output should be 01100000(only B and C are enabled). Suppose we define 4 states { 00, 01, 10, 11}, where 00 denotes displaying 1, 01 denotes displaying 2, 10 denotes displaying 4, and 11 denotes displaying 8. Also, we use X(t) to represent the input (i.e., the state of the button, 0 represents unpressed and 1 represents pressed). We assume the output is A,B,C,D,E,F,G (each represents the state of segment A, B, C, D, E, F, G).

You need to simulate the circuit diagram designed in this problem and submit a video demo to show the dynamic simulation results using online simulation software like https://www.falstad.com/circuit/

Thanks

Can you post the complete text of the problem. It's more typical for a student to be asked to design a counter with a particular count sequence and display the number on a single display (in your case).

#### dl324

Joined Mar 30, 2015
9,577
This full text of question:
The way I read it is that you have a counter that needs to display 4 numbers: 1, 2, 4, 8 (in that order) on a single 7 segment display.

Where did you get the idea that X can't be the clock?

#### CPCPCPPcode

Joined Dec 10, 2019
7
The way I read it is that you have a counter that needs to display 4 numbers: 1, 2, 4, 8 (in that order) on a single 7 segment display.

Where did you get the idea that X can't be the clock?
I thought they are different things.... aren't they? so actually the button can be served as clock?

#### dl324

Joined Mar 30, 2015
9,577
I thought they are different things.... aren't they? so actually the button can be served as clock?
That's something you need to clarify with your instructor.

#### CPCPCPPcode

Joined Dec 10, 2019
7
That's something you need to clarify with your instructor.
Okay, thx a lot!

#### dl324

Joined Mar 30, 2015
9,577
BTW, does your simulator tell you that you've shorted all of the flip flop outputs?