Minimize logic expression for each segment in 7 segment LED

[vick5821]

Hey guys, currently I am working on to find the minimize logic expression to lights up each individual segment in 7 segment LED

For segment a : B +D + A(bar) C(bar) + AC
For segment b : C(bar) + D + A(bar)B(bar) +AB

So far correct ? Can anyone provide me for the the next few logic ? want to compare my answer.


Thank you

 

[War_Spigot]

Looking at the datasheet for a 7 segment decoder would help. They usually have logic diagrams. From that you could write the equations for each segment and then try to simplify it.

 

[vick5821]

Looking at the datasheet for a 7 segment decoder would help. They usually have logic diagrams. From that you could write the equations for each segment and then try to simplify it.

yea..I wrote the equations, now I wanna compare the final answer

 

[Harald Kapp]

The homeworks section doesn't work like that.

You provide the answer and we can tell you (hopefully) whether it is correct or not. And if not guide you along to find the right answer.

Harald

 

[vick5821]

This is my final answer. Correct me if I am wrong

 

[Harald Kapp]

For reason of little time I checked only sheet one for segment a. It looks entirely correct to me.

There is a second approach: Look at the KV diagram for segment a again. You evaluated, correctly, the situations where a=1 (or a=x) to arrive at an equation with 4 terms. What happens if you look at the same diagram but this time watch out for a=0? The equation will have only 2 terms, at the cost of each single term being more complex. From the equation for a=0 you get a=1 by negating the complete equation.
Note: this is only a hint for an additional solution and shall in no way imply that the solution you found by yourself is not well evaluated.

Harald

 

[Laplace]

Here is an example of using a spreadsheet (O Calc) as a logic simulator. The conditional formatting effects do not seem to carry through if you open the .ods file in Microsoft Excel. Segment 'd' seems to have a problem for the BCD value 0110.

 

[vick5821]

Here is an example of using a spreadsheet (O Calc) as a logic simulator. The conditional formatting effects do not seem to carry through if you open the .ods file in Microsoft Excel. Segment 'd' seems to have a problem for the BCD value 0110.

How to use that file ?? @@@

 

[(*steve*)]

Download LibreOfffice.

 

[vick5821]

How about other segment ? Is it done correctly ?

 

[Luke Vassallo]

I would suggest, that you simulate your circuit, it's important to do this especially if you are building your circuit. First you know I its behaving correctly and secondly it will help you troubleshoot errors when a certain part of your circuit isn't working.

I would suggest icircuit - very basic and working wonderfully with logic circuits or multisim.

Hope this helps. Be sure to fully annotate your diagrams!

 

[Ratch]

Hey guys, currently I am working on to find the minimize logic expression to lights up each individual segment in 7 segment LED

For segment a : B +D + A(bar) C(bar) + AC
For segment b : C(bar) + D + A(bar)B(bar) +AB

So far correct ? Can anyone provide me for the the next few logic ? want to compare my answer.


Thank you

You can try a program I wrote to check logic calculations. Expand the zip file into a temporary file and read the documentation. Take your K-map answer and plug it in. My program will give you the minterms. If the minterms match what you used on your K-map, then your reduction is correct. My program assumes that your logic variable "A" is the highest order variable, whereas you assume that "A" is the lowest order variable. Therefore, you have to transpose A-->D, B-->C, C-->B, D-->A . I checked the first two calculations you made and they appear correct.

Ratch