Good day!

I'm working on a project which is 4 bit binary multiplier using combinatorial circuits. I'm using 7408, 7486 and 7432 ICs. I did use fritzing program to layout the connections and afterwards did it on the breadboard. However, it is not working properly I already double checked the connections in breadboard and it's the same with the one I layout.

Can please someone tell my mistakes? I've attached the image of the connections and the schematic diagram which I followed. Thanks!

P.S. I just substitute 4081, 4070 and 4071 because I couldn't find 7408, 7486 and 7432 ICs in the program.

 

I'm certainly not going to wade through that rats nest of wiring.

What kind of switches are those? SPST? SPDT? How are they connected?

You don't have any current limiting resistors on the LEDs. Even if the simulation program doesn't care, YOU should.

Most importantly, "it is not working properly," gives us nothing to work with. HOW is it not working properly. WHAT does it do that indicates that it isn't working properly? What, if anything, IS it doing properly?

 

You actually built the circuit as shown in the breadboard?


This part I dont understand....

You are connecting one side of the button switches to 5V, and the other side to 0V. But the green wire goes to the middle column which is nowhere......

Allen

 

You actually built the circuit as shown in the breadboard?

View attachment 122470
This part I dont understand....

You are connecting one side of the button switches to 5V, and the other side to 0V. But the green wire goes to the middle column which is nowhere......

Allen

Sorry that part was confusing, I had a 6 pin push on/off button. I just did that for my reference..

 

I'm certainly not going to wade through that rats nest of wiring.

What kind of switches are those? SPST? SPDT? How are they connected?

You don't have any current limiting resistors on the LEDs. Even if the simulation program doesn't care, YOU should.

Most importantly, "it is not working properly," gives us nothing to work with. HOW is it not working properly. WHAT does it do that indicates that it isn't working properly? What, if anything, IS it doing properly?

Sorry, I did put resistors on my LEDs. It's not working properly because the output isn't correctly displaying what I'm expecting..

 

This is the connection that I did.. Is there a mistake here? Thanks!

 

Here is the updated one..

 

Sorry, I did put resistors on my LEDs. It's not working properly because the output isn't correctly displaying what I'm expecting..

This gives us no more information that we started with. It's like asking a mechanic on the phone to tell you what is wrong with your car and all you will tell them is that it isn't doing what you expect.

What, EXACTLY, is it doing that you don't expect? WHAT is the output for a given input that is incorrect? We are not going to reverse engineer your entire design to determine whether it is correct or not -- that's YOUR job. We will help YOU learn how to troubleshoot your design based on how it is and is not meeting spec.