Problem/Statement
For this project, we were to create a circuit that would displace our birthday on a seven segment display. Our birthday, being in the for 00-00-00 (Day-Month-Year). We were not instructed to prototype this project, but to simulate it in MultiSim (Circuit Design Software).
Brainstorming
To start off, what is a seven segment display? The picture below shows an example of one. It is a group of seven LED (lights) that create a figure eight. When certain segments light up, a number or dash is created..
To determine when the light will turn on, you must find a logic equation for each segment or letter. To do this you must create a truth table the inputs must represent the numbers in you birthday (using binary numbering). Then you go to each segment in the table and put a (1) for each combination of the number in the display that is supposed to be one. An example is shown below. (Click to expand)
From this table you get a logic equation for each segment. (each minterm is from the ones in the vertical column of each segment)
Segment A= X'Y'Z'+X'Y'Z+X'YZ'+XY'Z'+XYZ'+XYZ Segment B= X'Y'Z'+X'Y'Z+X'YZ+XY'Z'+XYZ'+XYZ Segment C= X'Y'Z'+X'YZ+XY'Z'+XYZ'+XYZ Segment D= X'Y'Z'+X'Y'Z+X'YZ+XY'Z'+XYZ'+XYZ Segment E= X'Y'Z'+X'Y'Z+X'YZ+XY'Z'+XYZ Segment F= X'Y'Z'+X'YZ+XY'Z'+XYZ'+XYZ Segment G= X'Y'Z+X'YZ'+XY'Z'+XY'Z+XYZ'+XYZ This would be a very complex circuit, to simplify that K-Mapping can be used. Each K- Map in shown to the right for each segment. (Click to expand) |
Circuit Sketch
Now, using each of the logic expressions Provided form the K-Mapping, a sketch can be drawn. Further instructions stated that at least one segment must only use NAND, one must only use NOR, and one must only use AOI Logic. The rest of the segments can be whatever we choose them to be. I choose the rest of mine to use NAND because it was the quickest. (Click to expand)
Circuit Design Simulation
Following the sketch i simulated the design on MultiSim, so that i could test in and make sure that each segment works. Below is the circuit built in MultiSim.