AOI Logic Design - Majority Vote

The board of directors has four members: president, vice-president, secretary, and treasurer. Each member has a single yes/no vote. For a decision to pass, a majority of the board members must vote yes. In the event of a tie, the president's vote is used to break the tie (if the president votes yes, the decision passes. If the president votes no, the decision fails.).

In this project, you will use only AND, OR, and Inverter logic gates, frequently referred to as AOI logic, to design, simulate, and build a Majority Vote voting machine that meets these design specifications.

After reading the introduction, I first created a truth table by reading the project description and working through all of the possible combinations. Anytime there were only zero or one yes votes, the decision was 0. If there were two yes votes and one was the president, then the decision was 1, and succeeded. If there were at least three yes votes, the decision was 1 and succeeded. I created an unsimplified logic expression from this by adding up all of the combinations that resulted in an output of 1. From here, I created the unsimplified circuit in MultiSim to test it. After verifying the circuit and expression, I used boolean logic to simplify the expression into the more simplified expression shown below. I also created this circuit in MultiSim and verified its correctness with the project scenario. With everything created, tested, and verified digitally, it was time to move on to making it in real life. We used circuit boards and replicated the circuit with wires, a resistor, logic gates, and a light bulb for a probe. IC testers were utilized to ensure that the logic gates were working correctly. Wires were stripped with a wire stripper so the circuit board did not get too messy with loose wires everywhere. We plugged these completed circuit boards into the computers with the proper drivers and software, and tested them.

D = PV + VST + PS + PT or D = P(V + S + T) + VST