Traffic Light State Machine Project

Purpose

The purpose of this project was to design a state machine that would control 2 stoplights which would act together and function like a normal intersection. The goal was to not have both turn green at the same time.

Procedure

Drew out the state machine for each
Made the state transition table based off of the state machine for each
Got the logic equations using the state transition table for each
Simplified the logic equations using Karnaugh maps for each
Designed the circuit in Multisim for stop light 1 and Tinkercad for stop light 2

Single Traffic Light Design

State Graph

This mapped out the necessary states we needed for the single stop light

State Transition Table

We created the state transition table based off of the state graph. This allows us to see the logic for each state.

Minterm Expressions & Simplification

This simplified the data in the transition table into logic that we could use input into our Multisim design

This shows my Multisim circuit design for the single stop light. It uses 2 flip flops to output green, yellow, and red.

Dual Traffic Light Design

State Graph

This state graph shows states required for the circuit, and the information within each state.

State Transition Table

This table takes the information from each state and transforms it into a more readable format which we can use to determine the logic for the double stop light.

Minterm Expressions & Simplification

This simplified the information in the state transition table into data that we could implement into our Multisim circuit.

IMG_5811.MOV

Here is a video of the working Multisim circuit (Easiest to see if full screen, Shows the stoplights working like at an intersection).

Conclusion

State machines are very useful for anything that requires the next output of a machine to be dependent on another previous output. State graphs and transition tables are very helpful for planning out a state machine by making sure you have the correct number of states and that each state has the correct information. The transition table is very helpful for getting the logic for your circuits as it helps visualize the information required for each state.

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