Design of Traffic Light System

Contents

Task 1

Design Specification

Design 1

Complete Block Diagram of the traffic light system

State diagram Table

Circuit simulation using Multisim software,

Task 2

Timing Counter

Task 3

Figure 13 (Main red and amber sub amber)

Task 4

Remake design

LIST IN Tab;e

Table 1(State diagramme)

Table 2(D type Flip Flop)

Table 3(design cost)

Table 4(compare table)

List in Figure

Figure 1: traffic lights system

Figure 2(block diagrammed)

Figure 3(Moore model)

Figure 4 (main red and sub green for 10s)

Figure 5 (Main amber and sub red and amber for 2s)

Figure 6(main red and sub green for 10s)

Figure 7 (Asynchronous counter for timing counter)

Figure 8(The Design is 30s counter for main road in Asynchronous counter)

Figure 9 (The Design is 20s counter for side road in Asynchronous counter)

Figure 10 Main green and sub red

Figure 11 (Main amber and sub red and amber)

Figure 12 (Main red and sub green)

Figure 13 (Main red and amber sub amber)

Figure 14(remake design)

Design Specification

Design specification prepared for a single main and sub -road junction in rural area is given below

• The green light for the main road will be stay ON for 30s.

• The green light for the side road will be stay ON for 20s.
• The amber caution light will say ON for 5s between changes from green to red.
• Main road and side road timing countdown should display in a 7segment display.
• Sequence change of the traffic lights show in the Appendix I.

The traffic light system for a single main road and sub road junction in a rural area.

Complete Block Diagram of the traffic light system

Figure 2(block diagrammed)

The FSM description stands for “Finite state machines”. the Finite state machines are the most common controllers of machines. It’s In the example Traffic light, the intersection of a main road with a side road is controlled by two traffic lights. FSM has three inputs (T1, T2 and T3) AND six outputs (Rm, Am, Gm, Rs, As and Gs)

In here

Rm is Red light for main road

Am is Amber caution light for main road

Gm is Green light for main road

Rs is Red light for sub road

As is Amber caution light for sub road

Gs is green light for sub road

T1 time is 30seconds

T2 time is 20seconds

T3 time is 5seconds

Complete Moore model state diagram for traffic light system

State diagram Table

Table 1(State diagramme)

State Assignment in Gray code

Here using gray code for states

State transection table

Here using D type flip flops for design a circuit

Table 2(D type Flip Flop)

Simplified equations for the system.

From Laws of Boolean Algebra

(

The equations are,

Circuit simulation using Multisim software,

Figure 4 (main red and sub green for 10s)

Figure 5 (Main amber and sub red and amber for 2s)

Figure 6(main red and sub green for 10s)

Timing Counter

Figure 10 Main green and sub red

Figure 11 (Main amber and sub red and amber)

Figure 12 (Main red and sub green)

Figure 13 (Main red and amber sub amber)

Task 4

Table 3(design cost)

Remake design

Figure 14(remake design)

Compare the cost

• In new design cost is less than old design

Reference

Mano M.M,Michael D.C. (2008).Digital Design.New Delhi:PHI.

Floyd,L.(2011).Digital Fundamentals.10th ed.India:Pearson. p271- 287.

http://www.topssrilanka.com/article24948-new-traffic-ligth-system-atbambalapitiya.html.Lasr

http://www.sundayobserver.lk/2012/06/03/imp01.asp