[SOLVED] Comp311 – now that we’re familiar with digital software simulator and combinational logic circuit design techniques, e.g., truth tables, sum of product (sop) expressions, and sop simplification using karnaugh maps, and it’s time to take things to the next level! in this lab you’re going to be wiring up a 7-segment led display!

Seven-segment displays are widely used in digital clocks, electronic meters, basic calculators, and other electronic devices that display numerical information. If you’ve never seen a 7-segment display before, here’s one below:

As you can see, there are 7 seperate LED’s that turn on & off depending on the number (or letter) that you want displayed. A 7-segment display has four Boolean inputs (A, B, C, D) and Seven Boolean outputs
(Fa, Fb, Fc, Fd, Fe, Ff, Fg) that represent display segments. In general, four Boolean inputs are decoded to seven Boolean outputs that will be used to display 1 of 16 hexadecimal values (0, 1, 2, 3, 4, 5. 6, 7, 8, 9, A, b, c, d, E, F).
To determine what value will be displayed on the 7-segment display you take the binary combination of the 4 input bits and convert to hexadecimal, and the hex-value is what should be displayed. For instance when the 4 input bits are 0000, this translates to hex-value 0, and 0 is what is displayed. For input bits 1111, this translates to hex-value “F”, and this is what is displayed. The image to the right shows the layout of the 7 LED’s:
Additionally, the following truth table to the right is crucial to constructing the circuit for a 7-segment display:
For example, when inputs A, B, C, and D are all off (0=off) then output segments Fa through Ff will be turned on (on=1) to display the hex value “0†We’ve updated the truth-table for you above.
Similarly, the output segment Fa will be turned on for the following input combinations – I’ve also updated the truth-table for you.
A,B,C,D=0
A,B,D=0 and C=1
A,B=0 and C,D=1
A,C=0 and B,D=1
A,D=0 and B,C=1
A=0 and B,C,D=1
A=1 and B,C,D=0
A,D=1 and B,C=0
A,C=1 and B,D=0
A,B,C=1 and D=0
A,B,C,D=1
Task 1
Using the given “truth-table.csv” file in the repo, fill in the rest of the truth table. Determine for each number or letter, which of the 7 LED’s will be on (1) or off (1). You will see that the the given row and column is also given in the excel document. When you finish the truth table, we reccomend commiting your changes and submitting to Gradescope to see if it is correct. If you have an incorrect truth table, your circuits in the next part will not be correct!
Task 2
Now that we’ve constructed the truth table, it’s time to get ready to build the circuit! Before we start diagramming on Digital, we need to figure out how we’re going to wire the 7-segment display up.
Step 1
Using the completed truth-table, find the sum of products (SOP) Boolean expression (not simplified) for output segments Fa – Fg Simplify the SOP Boolean expression for each of the output segements Fa – Fg using the Boolean identities.
Alternatively, you can contruct Karnaugh maps based on the completed truth-table for each output segment Fa – Fg, and use the Karnaugh map to find the simplified SOP boolean expression
At this stage you should have 7 boolean expression in SOP form that are as simplified as possible. if you don’t simplify the boolean expressions or put them in SOP form, you’re going to have a very tough time while constructing the circuit in Digital
Step 2
Draw the combinational logic circuits for each of the SOP expressions you obtained in Step 1. This will be the basis for what we are going to input into Digital
Step 3
Now comes the hard part, actually putting & combining these circuits in Digital. Note: This is going to be a complicated circuit
We’ve provided a template file for the assignment, labeled “Lab01.dig” in the repository. Make sure to build & commit your changes in this file. We’ve provided you 4 inputs labeled A-D, these are the only inputs you will need for this assignment!
Note: Each of your 7 circuits you drew in step 2 will use the same 4 inputs A-D
Construct your circuits! You can select logic components from the “Components -> Logic” menu. You should only need AND, OR, and NOT components for this assignment.
You can find the 7-segment LED display under “Components -> IO -> Displays -> Seven-Segment Display” Note: DO NOT use the Seven-Segment Hex Display Remember that each of your 7 circuits will connect to one of the LED’s on the Seven-Segment Display. I’ve provided the image on the right to display which circuits connect to which inputs on the display. The bottom right input on the display must connect to ground. You can find the ground element in “Components -> Wires -> Ground”
IMPORTANT
When you finish wiring up your circuits, you should have 7 OR gates in your design (7 SOP expressions -> 7 OR gates). Each of these OR gates should lead to one input on the 7-segment display as shown in step 3. Below is an example:
In order for the autograder to work, you MUST add output (Components -> IO -> Output) components on the end of each OR gate and label the component (using right-click for windows and control-click for mac) with the input that it is going to, (Fa, Fb, Fc, Fd, Fe, Ff, Fg). Don’t touch your wires, just place the output component on the output of each OR gate, and then label it accordingly. You MUST label the output components as (Fa, Fb, Fc, Fd, Fe, Ff, Fg) exactly as written. Below is an example:

Task 3: Submit your assignment
Assignment submissions will be made through GradeScope.
1. Submit modifications using the commit Github Desktop instructions.
2. Update remote (origin) repository using the push Github Desktop instructions.
3. Go to the COMP 311 course in GradeScope and click on the assignment called Lab 01.
5. You should see a list of your public repositories. Select the one named lab-01-yourname and submit it.
6. Your assignment should be autograded within a few seconds and you will receive feedback.