TinkerCAD 7-Segment Display Not Showing on Simulation

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
Hi, I am only on my 5th week trying out TinkerCAD for our Logic Circuits course. We are tasked to create a 7-Segment Display Using Logic Gates only. I did all the boolean expressions needed for each segment using K-MAP, and identified the boolean expression needed to create my circuit.

I am doing the segment A circuit and wiring currently but the 7-Segment didn't output anything after simulating. It should have light on Segment A.

Here is the link for my TinkerCAD:
https://www.tinkercad.com/things/jd...e=QOjNbOD_t32_42qIfuNkjnWE0Nt-Yi42CNuwUalVJ_s

How could I solve this? Thanks for those who will help. Please let me know if there is a problem with the link or you need to know more.
 
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Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
Your link appears to require membership to access. Please post the schematic on this site.
Hi, I already fixed this problem. I just wanna inquire about another problem that I encountered. The same circuit that I mentioned on my post, but, if I try and simulate it, the 7-segment display is not showing. I'm not sure where the exact problem is because I did all the connections based on my equation. I just can't see where I got it wrong for the output not to work. This one is still for Segment A circuitry. The output should be that the segment A already has light on the 7-Segment.

Capture.JPG

BTW, sorry for the mess, I am still working on how to wire properly.
 

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dl324

Joined Mar 30, 2015
14,467
I just wanna inquire about another problem that I encountered.
Do you have a schematic? I don't trace breadboards unless I suspect that the person in question doesn't know how to wire properly.

You shouldn't run wires over/under components or along the pins because we can't trace/determine connectivity.
1650641546248.png

If you're not required to use that simulator, I'd use something that simulated from a schematic:
1650641821273.png
This is from a binary to hex converter I did in DigitalWorks (a free simulator that runs on Windows). It does have some standard components, but I don't use them because schematics using them are difficult to read.
1650642087860.png
 
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Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
Do you have a schematic? I don't trace breadboards unless I suspect that the person in question doesn't know how to wire properly.

You shouldn't run wires over/under components or along the pins because we can't trace/determine connectivity.
View attachment 265601
Hi, sorry but I directly used the equation itself and made the wirings on breadboard and didn't do a schematic anymore. I'm hoping you could take a look at the link itself if it's okay, and see the problem. I'll try to fix the wires later. I just want someone to take a look and see where might the problem be (if it's okay). Thanks.

https://www.tinkercad.com/things/jd...e=QOjNbOD_t32_42qIfuNkjnWE0Nt-Yi42CNuwUalVJ_s
 

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
Hi, I am only on my 5th week trying out TinkerCAD for our Logic Circuits course. We are tasked to create a 7-Segment Display Using Logic Gates only. I did all the boolean expressions needed for each segment using K-MAP, and identified the boolean expression needed to create my circuit.

I am doing the segment A circuit and wiring currently but the 7-Segment didn't output anything after simulating. It should have light on Segment A.

Here is the link for my TinkerCAD:
https://www.tinkercad.com/things/jd...e=QOjNbOD_t32_42qIfuNkjnWE0Nt-Yi42CNuwUalVJ_s


How could I solve this? Thanks for those who will help. Please let me know if there is a problem with the link or you need to know more.
There seems to be no limiting resistor from "driver-"/logic- ic to the 7-seg. LCD indicator
I tried adding a 1k Resistor from the output to the A pin of the 7-segment but it doesn't seem to work. Would you mind taking a quick look to see where the problem might be?
 

ci139

Joined Jul 11, 2016
1,821
GFRAB // 7seg pinnout can be swapped in between Com-AN / Com-CA
EDRCG // i a bit cleaned up the ckt - but i didn't checked it's functionality yet . . .
7seg-mod-a.png
 

ci139

Joined Jul 11, 2016
1,821
i changed it to a common cathode as you had the Comm connected to neg supply rail - it did lit up the segment A but it didn't respond to any alteration of the toggle button states ??? sorry . . . though i didn't run through all the 16 combinations . . . = i might've missed something

? are you trying to build the 4-bit to 7-seg hex coder < such will be quite complex . . . should put the schematic diagram on paper before attempting to tile it up on pin-boards
random about https://www.dcity.org/portfolio/i2c-7-segment-led-library/ + a ROM version of the thingy https://www.futurlec.com/Datasheet/Motorola/MC14495.pdf
 
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Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
i changed it to a common cathode as you had the Comm connected to neg supply rail - it did lit up the segment A but it didn't respond to any alteration of the toggle button states ??? sorry . . . though i didn't run through all the 16 combinations . . . = i might've missed something

? are you trying to build the 4-bit to 7-seg hex coder < such will be quite complex . . . should put the schematic diagram on paper before attempting to tile it up on pin-boards
random about https://www.dcity.org/portfolio/i2c-7-segment-led-library/ + a ROM version of the thingy https://www.futurlec.com/Datasheet/Motorola/MC14495.pdf
Actually I'm only trying to make a 7-segment display using only logic ics and not with the actual decoder
 

ericgibbs

Joined Jan 29, 2010
15,526
Actually I'm only trying to make a 7-segment display using only logic ics and not with the actual decoder
Hi Sway,
That is not an easy task, this image of a decoder shows the complexity of the logic using Gates.
It could be simplified a little by dropping Blanking and Lamp testing section.
Post your version of the decoder.

E
EG 1579.gif
 

ci139

Joined Jul 11, 2016
1,821
One way to control each segment separately is to use a bit-mask
--e.g.-- the 7 switches (1 for each) or a register/buffer of 7-bits . . .

for encoder or decoder - depending how you call it :


A2F.png
a0:aF = 10110 11111 101011 goes for
DCBA
0000
...
0111
1000
...
1111
as
\(\begin{array}{|c|c|c|c|c|c|}\hline {} & B & B & \overline{B} & \overline{B} & {}\\
\hline D & 1 & 1 & 0 & 1 & C\\
\hline D & 0 & 1 & 1 & 1 & \overline{C}\\
\hline \overline{D} & 1 & 1 & 1 & 0 & C\\
\hline \overline{D} & 1 & 1 & 0 & 1 & \overline{C}\\
\hline {} & A & \overline{A} & A & \overline{A} & {}\\ \hline\end{array}\)
\(a=\overline{A}\left({B+\overline{C}+D}\right)+B\left({C+\overline{D}}\right)+AC\overline{D}+\overline{B}\ \overline{C}D\)
and obviously also
\(a=\overline{A\overline{B}\left({CD+\overline{C}\ \overline{D}}\right)+AD\left({B\oplus C}\right)+\overline{B}\ \overline{D}\left({A\oplus C}\right)}\)
the seg. a(0...F) may be optimized for the logical gates you'll use to implement it
 
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