Question

Question: A friend would like you to build an “electronic eye” for use as a fake security device. The device consists of three lights lined up in a row, controlled by the outputs Left, Middle, and Right, which, if asserted, indicate that a light should be on. Only one light is on at a time, and the light “moves” from left to right and then from right to left, thus scaring away thieves who believe that the device is monitoring their activity. Draw the graphical representation for the finite-state machine used to specify the electronic eye. Note that the rate of the eye’s movement will be controlled by the clock speed (which should not be too great) and that there are essentially no inputs.

Short answer

Answer

The graphical representation of a finite state machine is:

Step-by-step solution

Definition of a finite-state machine

The finite-state machine consists of the states and transitions from one state to another. It is a mathematical model of computation. This machine takes the string of symbols as input and changes its state accordingly. When an input is executed, the state changes, and output is produced.

Finite-state machine for “electronic eye”

The finite-state machine consists of three states. The state S0 represents the left bulb on, S1 represents the middle bulb is on, and S3 represents the right bulb is on. The left value on the transition edge is input and the right value is output. The input 0 always goes to the S0 state representing the reset state. On input of 1, the light moves from left to right and then right to left. The finite-state machine is given below: