(Based on microprocessor - 8085)

NETAJI SUBHAS INSTITUTE OF TECHNOGY

UNIVERSITY OF DELHI, DELHI

Submitted By:

AYUSH GUPTA (44/EC/13)

BHARTI (46/EC/13)

Faculty Advisor:

Prof.Dhananjay V. Gadre

ACKNOWLEDGEMENT

We would like to express our immense gratitude, indebtedness and heartfelt gratefulness to our guide, Prof. D.V. Gadre sir for his incomparable and immeasurable guidance throughout the course of this project titled as “Make the pattern”. We would also thank our parents and friends who have constantly supported us throughout the project

INDEX

DESCRIPTION OF PROJECT

INTRODUCTION

HARDWARE IMPLEMENTATION

BLOCK DIAGRAM

COMPONENTS REQUIRED

SCHEMATIC DIAGRAM

BOARD FILE

PICTURES FROM PROJECT

FLOW CHART

TESTING AND DEBUGGING

GANTT CHART REVISITED

CONCLUSION

BIBLIOGRAPHY

DESCRIPTION OF PROJECT

INTRODUCTION

Make the pattern is a game based on the player efficiency to complete

the pattern (square) in given amount of time. This game consist a 3x7

led matrix, three switches (S1, S2 and S3) and a 16x2 lcd. In a matrix of

three columns a set of three glowing leds i.e. first three of first column

and last three of last column will be given to a player initially.

Upon pressing a switch (S2) to start the game, randomly any set of

three leds will glow in the middle column. Player have to use the

switches to move the initial sets of leds to come in parallel with

randomly glowing leds to complete a 3x3 glowing led matrix (square

pattern). Player has to complete this task in a 3 seconds, failing this task

leads him to lose the game. LCD will also display the result at the end of

the game.

HARDWARE IMPLEMENTATION

8085

Microprocessor 8085 is developed by Intel Corporation. It is an 8 bit

microprocessor that uses +5V DC supply for its working. It is a 40 pin

device. A single Integrated Circuit (IC) has all the functional components

of a CPU namely Arithmetic Logic Unit (ALU), Control Unit and registers.

The 8085 microprocessor is an 8-bit processor that includes on its chip

most of the logic circuitry for performing computing tasks and for

communicating with peripherals.

1. Decoding circuit

Decoding circuit is used to enable RAM, EEPROM and 8255(I/O

device).We have used 74HCT138N decoder for the following decoding

circuit.

2. SID /SOD circuit

SID/SOD circuit is used to check the functioning of 8085 hardware.

3. Power circuit

The circuit can be powered with 5 V using micro USB. Ceramic and

electrolytic capacitors are used to remove high and low frequency

noises. To indicate the system is powered ON, a red led is used.

4. LED Matrix

A 3X7 led matrix consists of 21 leds is being used for the game. To

reduce hardware, instead of udn2981 we have used 3 pnp transistors

BC327 as we would have required only 3 out of 8 pins of udn2981 to

drive our matrix. Across each column, one pin is sourcing the current

only for one led at a time ,but a row pin have to sink the currents from

3 leds.8255 cannot able to sink this much of current so we have used

uln2803A.For column multiplexing we have used 470 ohms resistors.

8255

The 8255 is a programmable peripheral interface device designed for use in Intel microcomputer systems. Its function is that of general purpose I/O component to interface peripheral equipment to them microcomputer system bus.

There are three basic modes of operation that can be selected by the system software: Mode 0 – Basic input/output Mode 1 – Strobed Input/output Mode 2 – Bi-directional Bus We have used 8255 in mode 0 in which ports work either in input mode

or in output mode. The modes for Port A and Port B can be separately

defined, while Port C is divided into two portions as required by the

Port A and Port B definitions.

Port A, Port B and Port C lower are programmed in output mode, while

Port C upper is programmed in input mode as it is connected to four

push buttons. Port A is connected to 8 data lines of LCD, Port B and Port

C lower to matrix

LCD

A 16X2 lcd is interfaced with 8255 in 8 bit bus. It is used to display the

name, time and result of the game.

BLOCK DIAGRAM

Power

supply

COMPONENTS REQUIRED Sl. No. COMPONENTS QUANTITY

01 8085 microprocessor 01

02 Led matrix(3X7) 01

03 Led(5mm) 02

04 USB 01

05 Ceramic capacitor 23

06 Polarized capacitor 03

07 Resistor 28

08 Lcd(16X2) 01

09 Preset(10K) 01

10 Push button(10-XX) 08

11 Ic555(NE555N) 03

12 Decoder(74HCT138) 01

13 Connector(M10) 04

14 Latch(74HCT573N) 01

15 RAM(62256P) 01

16 EEPROM(58C256P) 01

17 8255 Interface 01

18 NOT Gate(74HCT04N) 01

19 Driver(ULN2803A) 01

20 PNP transistor(BC327) 03

21 Crystal(4Mhz) 01

SCHEMATIC DIAGRAM

BOARD FILE

PICTURES FROM PROJECT

FLOWCHART

No

Yes

No

No

Yes

Yes

Initialize memory, register and LCD

Check for S2 switch press

Switch

Pressed?

??

Initialize counter for 3 secs

Generate random no [1-5]

[

Glow corresponding leds set

and initial sets of leds

Read S1 and S3 switches for

downward and upward

movement

IS S2

pressed? Counter

=0?

Check pattern Display result on LCD

End

Start

TESTING AND DEBUGGING

1. Components testing-All ICs were tested on an IC tester and leds

on the breadboard. After completing the soldering, each IC was

checked by connecting a multimeter to their power pins. This was

done to ensure the supply of 5 Volts to each IC.

2. SID/SOD testing- a simple program of ‘SID-SOD’ was burnt on the

eeprom to check the working and connection between 8085,

RAM, EEPROM and Address Latch.

3. LCD testing-a program to print “HELLO” was burnt on the eeprom

to ensure the proper working of LCD. The contrast of the LCD was

adjusted with the help of 10k potentiometer.

4. Main code testing-The main code was divided into various parts.

These includes the subroutine of switches, multiplexing, delay of 3

seconds and random no generation. Each subroutine was

debugged individually which really helped us a lot to correct

logical errors. Syntax errors were easily removed as they were

shown in a simulator while assembling the code.

GANTT CHART REVISITED

PROPOSED

ACTUAL

CONCLUSION

On comparing between proposed and actual Gantt chart, making

schematic file and testing were not completed in the allotted time. The

schematic file was modified several times to meet our objective .Testing

part was delayed due to end semester examinations. We completed

our project successfully with some delay but with the best results.

The whole endeavour has been a great and fun learning experience. It

gives us a better understanding to correlate theoretical concepts to real

life implementation using microprocessor. We also experienced the

importance of time management and team spirit. The project gave us a

good knowledge of microprocessor, assembly language programming

and PCB fabrication.

Make the pattern video:

https://www.youtube.com/watch?v=NFDvCxZX6tE&feature=share

code for the project

https://drive.google.com/open?id=0B3MCpvhxCr2sWk45N1FaeEFfOH

M

BIBLIOGRAPHY

Microprocessor Architecture, Programming and Applications with the 8085 by Ramesh Gaonkar.

The 8085 Microprocessor: Architecture, Programming and Interfacing by K.Udaya Kumar, B.S.Umashankar

Quick Start Guide by CEDT, NSIT for EEPROM Programmer.

For datasheet https://drive.google.com/folderview?id=0ByFqcybodzN8LS1PRTliN1lSdUU&usp=sharing

www.sparkfun.com