[Type the abstract of the document here. The abstract is typically a short summary of the

contents of the document. Type the abstract of the document here. The abstract is typically a

short summary of the contents of the document.]

8085 INTERVALOMETER

EC-316 MICROPROCESSOR LAB

1

8085 INTERVALOMETER

EC-316 MICROPROCESSOR LAB

NSIT ,DELHI UNIVERSITY

BY:- GAURAV KUMAR(56/EC/13)

AND

AKSHIT GUPTA(22/EC/13)

2

PROJECT DESCRIPTION

We are implementing INTERVALOMETER using 8085 Microprocessor .This

device is an attachment or facility on a camera that operates the shutter regularly

at set intervals over a period. We will first make the user input the delay he

wants between the shots and then the no. shots he needs to take. We are using

push buttons to increment or decrement the values of time duration and no. of

shots and same will be displayed on the LCD. It is basically used for time-lapse

photography.

Time-lapse photography is a technique in which the frequency at which film

frames are captured (the frame rate) is much lower than that used to view the

sequence. When played at normal speed, time appears to be moving faster and

thus lapsing.

PROJECT REALIZATION

We were given this project by Prof. D.V. Gadre. We were very excited after

getting this project as both of us are interested in photography and we had never

done anything related to time lapse before .So it was great learning experience

for us.

3

ACKNOWLEDGMENT

We would like to express our gratitude to Prof. D.V. Gadre for encouraging us

throughout the entire process of making this project. Without his guidance we

wouldn’t have been able to accomplish this project. We are also grateful to Mr.

Akash Gupta for his constant guidance and help. We would also like to thank our

friends especially Anirudh Rustagi , Aman Virmani , Isha Chaudhry and Dishank

Narang for helping us throughout the project.

4

TABLE OF CONTENTS

S

NO.

TOPIC

1 PROJECT DESCRIPTION

2 PROJECT REALIZATION

3 ACKNOWLEDGEMENT

4. SCHEMATIC FILE

5. BOARD FILE

6. MATERIALS REQUIRED

7. TOP VIEW OF BOARD

8. BOTTOM VIEW OF BOARD

9. 8085

10. BLOCK DIAGRAM

11. RAM AND ROM

12. LCD

13. BUTTONS

14. 8255

15. FLOW DIAGRAM

16. TESTING THE BOARD

17. IMAGES OF THE HARDWARE

18. PROBLEMS FACED

19. CONCLUSION

20. BIBLIOGRAPHY

5

SCHEMATIC

6

BOARD FILE

7

MATERIAL REQUIRED

S.NO NAME OF COMPONENT QUANTITY

1. RESISTOR 33

2. CAPACITORS 28

3. 8085 1

4. RAM 1

5. EEPROM 1

6. CRYSTAL(4MHZ) 1

7. DECODER 1

8. 8255 1

9. LATCH(74HCT573N) 1

10. 8254 1

11. NAND(74HCT00N) 1

12. MALE HEADERS 2

13. FEMALE HEADERS 1

14. LCD 1

15. LED 4

16. PRESET 1

17. PUSH BUTTON 8

18. TRANSISTOR(BC547) 2

19. MINI USB 1

8

TOP VIEW OF BOARD

9

BOTTOM VIEW OF BOARD

10

THE 8085

8085 microprocessor is an 8-bit microprocessor with a 40 pin dual in line package. The address and data bus are multiplexed in this processor which helps in providing more control signals. 8085 microprocessor has 1 Non-mask able interrupt and 3 mask able interrupts. It provides serial interfacing with serial input data (SID) and serial output data (SOD).

It has a set of registers for performing various operations. The various

registers includes B, C, D, E, H ,L Stack pointer, Program

Counter, Temporary register and Instruction register

8085 is the brain of our circuit .It is responsible for all the data processing

and is used to initialize the peripherals attached to it .

It provides the 8 bit data to 8254 to set up the required delay between

consecutive shots.

RAM AND ROM can be accessed by using the data lines of 8085.

11

BLOCK DIAGRAM

12

RAM AND ROM

1. RAM or Random Access Memory is used basically to store data while running the

program. We can both read and write data into it. In our project we have used the

RAM majorly to store the latched values of the COUNTER 0 of 8254. This memory

is volatile. When the power is turned off, all its contents are destroyed

2. ROM or Read Only Memory is the main memory of the brain 8085. 8085 fetches

instructions saved sequentially in the ROM. Saved on the ROM is the entire program that the

8085 has to execute. We can only read from the ROM once it is connected to the board. We

have used EEPROM which is Electrically Erasable Programmable Read Only Memory, since

the information stored in this memory can be altered using electrical signals. Unlike RAM its

contents do not get destroyed when power is turned off and to write data into it we need an

EEPROM programmer.

3. RAM and ROM come in various sizes. We have chosen 8K ROM and 8K RAM. Our

work could have been easily accomplished by 2K ROM and 2K RAM but to be on the

safe side we took a larger memory. A larger memory leads to slight variations only in

the interfacing circuitry rest of the connections remain the same.

13

LCD

LCD (Liquid Crystal Display) screen is an electronic display module and find a

wide range of applications. A 16x2 LCD display is very basic module and is very

commonly used in various devices and circuits. These modules are preferred

over seven segments and other multi segment LEDs. The reasons being: LCDs

are economical; easily programmable; have no limitation of displaying special &

even custom characters (unlike in seven segments), animations and so on.

A 16x2 LCD means it can display 16 characters per line and there are 2 such

lines. In this LCD each character is displayed in 5x7 pixel matrix. This LCD has

two registers, namely, Command and Data.

The command register stores the command instructions given to the LCD. A

command is an instruction given to LCD to do a predefined task like initializing it,

clearing its screen, setting the cursor position, controlling display etc. The data

register stores the data to be displayed on the LCD. The data is the ASCII value

of the character to be displayed on the LCD. We are using it in 8 bit mode.

14

BUTTONS

These push buttons are connected in active high configuration in the circuit.So

when a switch is pressed it gives a zero on its corresponding pin .We have

connected these switches to the the port C of 8255 and configured port C as

input. Switch usage:-

1.Increment Button

2.Decrement Button.

3.Reset Button.

4.SID_SOD testing button.

The two remaining switches are available for some future modifications in the

project.

15

8255

The 8255A is a programmable peripheral interface (PPI) device

designed for use in Intel microcomputer systems. Its function is that of

a general purposes I/O component to Interface peripheral equipment

to the microcomputer system bush. The functional configuration of the

8255A is programmed by the systems software so that normally no

external logic is necessary to interface peripheral devices or

structures.

We are using 8255 in Mode 0 .

PORT CONFIGURATION:-

PORT A Output

PORT B Input

PORT C UPPER Input

PORT C LOWER Output

Only A0 and A1 pins of the port A are used .A0 is connected to the

focus led and port B is connected to the shutter led .

16

FLOW DIAGRAM

17

TESTING THE BOARD

1. Checked all connections using a multimeter

2.Checked all control signals on the oscilloscope.

3.Checked the functioning of audio amplifier section on the

oscilloscope.

4.Checked the functioning of 8254 on the oscilloscope.

5.Segregated working LEDs using multimeter and then soldered them.

6.Tested the SID-SOD program.

7.Tested the inputs and output of latches for any discrepancies.

18

SOME IMAGES OF THE HARDWARE

19

PROBLEMS FACED

1. Earlier we were focusing the camera before each photo. But it

was showing a very erratic behavior as till the till the time camera

focuses on the subject our click pulse was also going low .So the

camera was only able to focus on the subject and photos were

not clicked . We removed this problem by not focusing the

camera every time before clicking the picture .Instead we

manually focused the camera on the subject before taking the

first picture.

2. The camera was taking 1 shot less than the input no. of shots in

auto mode as it was missing the first shot every time .But if we

use it in manual mode or shutter priority mode then it was working

fine .

20

CONCLUSION

It was a great learning experience for us .Implementing a standalone

project on 8085 helped us understand this microprocessor more. We

learned both hardware and software aspects of the project .This

project also taught us what is the right way of tackling problem if we

are not able to figure something out. We learned the importance of

team work and time management throughout this wonderful journey .

BIBLIOGRAPHY

Ramesh S. Gaonkar: “Microprocessor Architecture, Programming,

and applications with the 8085”

Dhananjay V. Gadre and Nehul Malhotra:“Tiny AVR

microcontroller projects for the Evil Genius”

www.alldatasheet.com

www.sparkfun.com

21

22

23