# Birthday date project

#### saruman42

Joined Dec 7, 2011
2
Hello all, I am currently working on a project that requires me to build a circuit on multisim and then breadboard the design. I am currently having trouble in the multisim portion of the project. I'm posting all the information regarding what I have below.

What I'm supposed to do:
Design a combinational logic circuit and display it results on a seven-segment display

I have attached a photo of what I have done.

Birthday Boolean
(sorry, the truth table gets a bit messed up when I copy it in here)

A B C Date a b c d e f g
0 | 0 0 0 0 0 0 0 0 0 0 1
1 | 0 0 1 1 0 0 1 1 1 1 1
2 | 0 1 0 - 1 1 1 1 1 1 0
3 | 0 1 1 2 0 1 0 0 1 0 0
4 | 1 0 0 1 0 0 1 1 1 1 1
5 | 1 0 1 - 1 1 1 1 1 1 0
6 | 1 1 0 9 0 0 0 1 0 0 0
7 | 1 1 1 4 0 0 1 1 0 1 0

Equations:

a = A’BC’ + AB’C
b = A’BC’ + A’BC + AB’C
c = A’B’C + A’BC’ + AB’C’ + AB’C + ABC
d = A’B’C + A’BC’ + AB’C’ + AB’C + ABC’ + ABC
e = A’B’C + A’BC’ + A’BC + AB’C’ + AB’C
f = A’B’C + A’BC’ + AB’C’ + AB’C + ABC
g = A’B’C’ + A’B’C + AB’C’

All together:

(A’BC’ + AB’C) + (A’BC’ + A’BC + AB’C) + (A’B’C + A’BC’ + AB’C’ + AB’C + ABC) + (A’B’C + A’BC’ + AB’C’ + AB’C + ABC’ + ABC) + (A’B’C + A’BC’ + A’BC + AB’C’ + AB’C) + (A’B’C + A’BC’ + AB’C’ + AB’C + ABC) + (A’B’C’ + A’B’C + AB’C’)

Simplified:
a = AB’C + A’BC’
b = A’B + AB’C
c = AC + B'C + AB' + A'BC'
d = A + B'C + BC'
e = B'C + A’B + AB'
f = AC + B'C + AB' + A'BC'
g = A'B' + B'C'

(AB’C + A’BC’) + (A’B + AB’C) + (AC + B’C + AB’ + A’BC’) + (A + B’C + BC’) + (B'C + A’B + AB') + (AC + B'C + AB' + A'BC') + (A'B' + B'C')

NOTE: U7 AND is currently unattached.

Thanks in advance for any help.

#### Attachments

• 169.3 KB Views: 63
Last edited:

#### bertus

Joined Apr 5, 2008
21,044
Hello,

The images don't show as they are links to your local computer.
You can upload the images to our server:

Attachments and Images

How do I attach a file to a post?

To attach a file to your post, you need to be using the main 'New Post' or 'New Thread' page and not 'Quick Reply'. To use the main 'New Post' page, click the 'Post Reply' button in the relevant thread.

On this page, below the message box, you will find a button labelled 'Manage Attachments'. Clicking this button will open a new window for uploading attachments. You can upload an attachment either from your computer or from another URL by using the appropriate box on this page. Alternatively you can click the Attachment Icon to open this page.

To upload a file from your computer, click the 'Browse' button and locate the file. To upload a file from another URL, enter the full URL for the file in the second box on this page. Once you have completed one of the boxes, click 'Upload'.

Once the upload is completed the file name will appear below the input boxes in this window. You can then close the window to return to the new post screen.

What files types can I use? How large can attachments be?

In the attachment window you will find a list of the allowed file types and their maximum sizes. Files that are larger than these sizes will be rejected. There may also be an overall quota limit to the number of attachments you can post to the board.

How do I add an image to a post?

If you have uploaded an image as an attachment, you can click the arrow next to the 'Attachment Icon' and select it from the list. This will be inserted into your post and can be located where you want it displayed.

To include an image that is not uploaded as an attachment and is located on another website, you can do so by copying the full URL to the image, (not the page on which the image is located), and either pressing the 'Insert Image' icon or by typing
after it, ensuring that you do not have any spaces before or after the URL of the image. You can insert pictures from your albums (?) in this way too.
Bertus

#### saruman42

Joined Dec 7, 2011
2
Thanks for the advice, I attached the photo.

#### Georacer

Joined Nov 25, 2009
5,182
From what I understand, you want to display the rolling message "01-21-94". Check for a bit this link (http://en.wikipedia.org/wiki/7_segment), and see which segment (a,b,c...) is which. Are you sure you have your outputs correctly? Because, for instance, {abcdefg}={000001} isn't the code for 0.