Netaji Subhas Institute of Technology, New Delhi - 8085 …8085projects.in/wp-content/uploads/2016/12/34-38-Report.pdf · Netaji Subhas Institute of Technology, New Delhi Microprocessors

Netaji Subhas Institute of Technology,

New Delhi

Microprocessors Lab (EC-316)

CRICKET SCORE DISPLAY (MPU 8085 Project Report)

Under the supervision of

Prof. Dhananjay V.Gadre

DEPTT. OF ELECTRONICS AND COMMUNICATION

SUBMITTED BY:

Arnesh Majhi (34/EC/13)

Ashish kr yadav (38/EC/13)

ABSTRACT

Our accepted project was to design a cricket score display

using the 8085 microprocessor. Our designed device displays

the cricket score on the basis of information provided by a

Bluetooth connected android application. For the 8085

microprocessor to receive data from the Bluetooth module,

UART communication is used and the cricket score is then

shown on a LCD display.

The device fulfils the requirement of ardent cricket fans who

can watch the cricket score whenever they want without

compromising on their productivity.

The device that we plan to make is a prototype which will

receive information from an android application. In its fully

functional form it will be able to receive data straight from

the internet.

INDEX

ACKNOWLEDGEMENT

Firstly we would like to thank Prof Dhananjay Gadre for his

unconditional support and thorough guidance and initiative without

which this project would not have seen the light of the day.

We further express our gratitude for helping us at each stage of the

project. Furthermore we thank you for providing the necessary

components and access to facilities which enabled us to work

comfortably on our project.

We would also like to express our gratitude to the members of the

CEDT lab for their patience which played a major role in the successful

completion of our project.

Project Description

1) Why we made this?

The main application of MPUs is in fields where it is required that

human effort has to be minimized and to make the lives of human

beings simpler. This device is essential in a cricket crazy country

like India, as people cannot do without looking at a score. It is an

ideal product as it would be more convenient to look at a LCD

screen for the score as it would provide lesser room for

distractions, thus enhancing productivity.

Another use of this product is that when no matches are going on,

it can simply be used for displaying messages

2) How we made this?

In our project we interfaced a Bluetooth module (HC-05) with

serial-in and serial-out data pins of the 8085 MPU using resistors.

We then interfaced the 16x2 LCD display with the 8085 MPU

using 8255 peripheral device.

3) What we made?

COMPONENTS USED:

S.NO NAME OF COMPONENT QUANTITY

1. RESISTORS 14+ 1 trim-pot

2. CAPACITORS 14

3. 8085 1

4. 74HCT04(NOT GATE) 1

5. 74HCT573 1

6. 74138 (DECODER) 1

7. HC-05 Bluetooth Module 1

8. 8255 1

9. 32K ROM(28C256) 1

10. 32K RAM(62256) 1

11. RED LEDs 2

12. MINI USB PORT 1

13. PUSH BUTTONS 2

14. 16x2 LCD Display 1

In this project, a 4MHz quartz crystal and 3 jumpers have also been introduced for testing purposes

BLOCK DIAGRAM

SCHEMATIC

BOARD LAYOUT

The size of our board is 107.62 x 110.47mm

CODE LOGIC FLOWCHART

The size of the final program is 621 bytes.

PROJECT IMAGES

UNSOLDERED BOARD

BOARD DURING THE TESTING PHASE

EEPROM PROGRAMMER

TESTING AND DEBUGGING 1) Hardware Testing

2) Software Testing

1) Hardware Testing

Hardware testing is done prior to the software part. It is quite possible

that some of the hardware may be malfunctioning, hence they need to

be tested. The possible reasons for these problems could be:

a) Soldering may not be proper leading to formation of bubbles

b) Some of the ICs may be defective.

c) Accidentally, some track may have got damaged

d) While making the schematic, some connection may have been

missed out.

e) Switches may not be functioning properly or the LEDs could be

defective.

I) SID/SOD Test:

This is a basic test that helps to check the basic components like

ROM, clock, 8085 IC, latch 74573 and the decoding logic of the

circuit. In this test, a predefined code is uploaded to the ROM

such that the LED remains on until the switch is pressed.

If this test fails, then do the following-

Case 1: Press the reset button. The SOD LED should blink. If it

doesn’t, then either the reset button is not working properly or

the switch is not connected to the 8085. This can be checked

with the help of a multimeter. For checking switches,

connections and LEDs, connectivity mode must be used.

Case 2: Reset switch is working, but the LED doesn’t turn off

when the SID switch is on. Check the components and

connections using multimeter. Also check the voltage across

SID and SOD pin, they should be same.

II) LCD Test- The display device that we have used is a 16x2 LCD

display. When the system is reset and the LCD has been

initialized, then the backlight should be on and must display a

series of dark circles. If blocks are not visible, then the

potentiometer must be adjusted to change the contrast.

Now, a code which initializes the 8255 and displays some

ASCII characters is uploaded to the ROM. When the power

supply is turned on, ideally the LCD should display the

characters. If it doesn’t, the following could be the cause of the

problem-

a) LCD is defective

b) 8255 IC may be malfunctioning

c) Other miscellaneous problems like some track getting

damaged while working.

*8255 can be checked by sending a code to set the value of one

of the ports of the 8255 and verifying it with the help of a

multimeter.

III) Bluetooth testing- This aspect is the most crucial part of the

project. Under default conditions, HC-05 bluetooth module has a baud

rate of 9600 which indicates that the BT module is capable of

transmitting 9600 bits per second and it is sending 1 start bit, 1 stop bit

and 8 data bits. There are two methods of verifying this-

a) Using oscilloscope- In our circuit, we had introduced

jumpers which were removable so that SID SOD testing

circuit can be disabled from the circuit. So, now effectively,

we have our BT module connected to our SID pin and at

SOD pin, we now connect the oscilloscope probes. A

character is sent via Bluetooth module app in our mobile and

the waveform is captured on the oscilloscope. This fulfills

two purposes- it verifies that the data received by Bluetooth

is correct or not and whether the data is being interpreted

correctly by the 8085 MPU properly or not.

The above wave was formed when we transmitted the character ‘A’

through BT module which has an ASCII value of 41H and this can be

verified in the above waveform. It also shows that the time period of the

wave is 104us which proves that the BT module is operating at 9600

Baud.

b) Using AT command mode- In order to configure the default

settings or verifying the settings of the BT modules, one has

to use a Arduino Uno/ Nano to configure the settings

2) Software testing- There is no scientific technique to solve the

software errors. This can be done only by accurate calculation. In

this project, synchronizing the Bluetooth with the 8085 MPU was a

tedious and time consuming process which required a lot of

efficient and accurate calculations.

CONCLUSION

This project is working as expected. This implies that both

hardware and software components are working properly.

This project would not have been possible without the motivation

and guidance from Professor Dhananjay Gadre. Students from the

CEDT lab were also very helpful and supportive.

FUTURE APPLICATIONS The device that we have made is a general purpose device and

can be used for a wide range of applications such as wireless

notice board as well as applications such as message display.

BIBLIOGRAPHY

1) Microprocessor Architecture, Programming, and Applications with

the 8085 by Ramesh Gaonkar, Fifth edition, Penram International

Publishing. ISBN 81-87972-09-2 2) The 8085 Microprocessor: Architecture, Programming and

Interfacing by K. Udaya Kumar, Pearson Education India, 2008.

ISBN 978-81-7758-455-4

3) http://www.instructables.com/id/Modify-The-HC-05-Bluetooth-

Module-Defaults-Using-A/step3/Steps-To-Switch-The-HC-05-

Into-Command-Mode/

4) 8255 Datasheet:

http://www.alldatasheet.com/datasheetpdf/pdf/66100/INTEL/8255

A.html

5) Introduction to LCD Programming: http://www.8052.com/tutlcd