In this project we designed a majority voting machine to help the board of directors to
make decisions on presidential elections in Florida. This would help prevent an excess
of over votes or under votes. A controversial presidential election would be prevented
from ever happening again when the machine is used. We had to create a truth table
from the conditions given to us. Next, we had to find the simplified logic expression from
the un-simplified expression. After we found that, we created a digital representation of
the bread boarding to simplify the process of actually bread boarding. Once that was
completed, we were able to start bread boarding. We needed three 74LS08J gates, a
lot of wires, and an LED to test the logic circuit. At first there was an error in our bread
boarding but we were able to fix that and get the correct output. To make it easier to
spot our errors we color coated the wires based off of which switch they were
designated to. We were able to easily locate wire that was plugged in incorrectly and fix
it.
We read the problem and sorted out the important information. From that, we created
a truth table from the conditions given to us. Then, we wrote the un-simplified logic
expression from the table. Using this equation, we used circuit design software on
the computer to build a rudimentary circuit based on that equation. To follow the
paths of the inputs, we changed the colors of the wires so that each electrical
pathway was easily identifiable. Because of this, troubleshooting was really simple
and we were able to find where the inputs were not creating the correct output. This
equation and circuit is needlessly complicated and uses too many parts, so we
simplified the equation and then built a circuit on the computer using the newer
equation. From this digital circuit we built a circuit using a breadboard and chips with
multiple gates inside them. To test that we built it correctly, we used an LED as the
signal that power was coming through. There were certain restrictions we had when
building the circuit, such as limiting ourselves to only 2-input AND gates, 2-input OR
gates, and inverters. While we were building, we tested certain electrical pathways
by using LEDs to see if electricity was passing through.
Do not be afraid of new technology, it is all developed to electronically make things
simpler. For example, I created a Majority-Vote Voting Machine that simulates the
president, vice president, secretary, and treasurer voting on a decision that
electronically shows whether a decision fails or passes based on the inputs used. The
conditions for a decision to pass among the board of director's four members is if three
or more vote yes. Each member has one vote. However, in the event of a tie, the
president's vote is used to break the tie. For example, if there are two votes for yes with
the president being one of them, then the vote passes. If the president is one of the
votes for no, then the vote does not pass as the president's vote is used as the
tiebreaker while not actually being worth more than one vote. In creating a design for a
machine that does this, I first created a truth table, which is a table of values that
analyzes all the possible inputs for votes and what their outcomes would be to
understand which combinations of votes I would need to focus on to create a circuit that
shows a positive output. Once the table was created, I wrote out an unsimplified logic
expression in Sum-Of-Products form which is the format used to write logic expressions
out. After that was done, I had to simplify it since creating a circuit with as many
expressions in the un-simplified logic expression would require many chips and be too
hard to build. To simplify the expression, I used boolean theorems, which are pretty
much digital electronic versions of mathematical equation laws and rules that can be
used to simplify, expand, or rearrange equations and expressions. So, after doing many
steps of simplification using boolean algebra, I went from an expression with eight parts
that would require twenty four gates to an expression with four parts that requires only
eight gates. Once creating the design was done, all that was left to do was actually build
the machine on a breadboard. A breadboard is a circuit board where electricity can flow
and we are using these to practice wiring circuits and experimenting to see how they
work along with using them for activities to learn about circuits. We used one to build a
circuit that would allow our majority vote machine to function. In doing so we needed
three chips that would act as "and '' and "or '' gates, which "activate" if certain conditions
are met to allow the current to keep flowing along the circuit. Once the board was set up
with proper chips, wiring was done following a diagram with "pin outs' ' that were
numbered to correspond to certain parts on each chip. Simply following this blueprint for
building the circuit was easy since all the work to create the simplest circuit was already
done with the boolean algebra simplification. Finally, when all the wires were in their
proper place and connected, the machine was done and followed the protocol with the
light lighting up to signify a decision being passed based on the inputs representing
votes being yes or no.