Designed by-Yogesh Kumar 1

How to design a electronic system ?

Block diagrams

Electronic circuit

HACS

Mobile remote control

DTMF & Cell phone

Mobile network

Signal Decoding

MCU

Interfacing MCU & 220VAC Mains supply

Conclusion

Designed by-Yogesh Kumar 2

Pick a problem from daily life.

Check what you have & what you want ?

Design flow of process.

Draw block diagrams.

Explore each process as you can.

Now its time to design electronic circuit. Choose electronic

components as per requirement.

Assemble & connect complete system circuit.

Test it , Now your system is ready to work.

Designed by-Yogesh Kumar 3

Block diagrams

Designed by-Yogesh Kumar 4

PROCESS PROCESS

OUTPUT

INPUT

You Have

You Want

SYSTEM FUNCTION

Electronic circuit

Designed by-Yogesh Kumar 5

Clock Generator Decade Counter

HACS [Home Automation Control System]

Home Appliance Control System accessed by a remote device such

as mobile phone or a palm-top(PC) to allow a home owner to control,

monitor and coordinate home appliances.

The following picture gives an

overview of how the system is works.

HACS

is a system which provides

various services to remotely

operate on home appliances.

The HACS system receives

commands from remote devices that are

manipulated by user.

Designed by-Yogesh Kumar 6

Need of Automation

Designed by-Yogesh Kumar 7

1. Saves time

2. Save money (Long run)

3. Self Maintenance

4. Security

5. Makes life easy

When: you are in a traffic jam

on the highway

What: You set microwave

oven in a slow cooking mode

Oven

Mobile Network & Remote Control

Designed by-Yogesh Kumar 8

SMS Based

DTMF Based

GSM Data logging

BTS

MS

DTMF- High Compatibility with all cell phone models Very cheap ,Easy to implement

BTS

GSM / CDMA

NETWORK

MS

DTMF Signals

DTMF is a signalling system for identifying the keys or better say the

number dialled on a pushbutton or DTMF keypad.

DTMF is a multi frequency tone dialling system used by the push

button keypads in telephone and mobile sets to convey the number or

key dialled by the caller.

DTMF has enabled the long distance signalling of dialled numbers in

voice frequency range over telephone lines.

DTMF (Dual tone multi frequency) as

the name suggests uses a combination of two

sine wave tones to represent a key.

These tones are called row and column

frequencies as they correspond to the layout of

a telephone keypad.

Designed by-Yogesh Kumar 9

DTMF signaling application

DTMF tones are thus mainly used at the telephone switching

centres for detection of dialled/called number.

IVR systems , Call centers ,Security systems.

DTMF tones were also used by terrestrial stations for turning on

and shutting off remote transmitters.

Designed by-Yogesh Kumar 10

DTMF to BCD decoding

Designed by-Yogesh Kumar 11

3.5 mm Jack

3.5 mm audio

connector

220VAC Mains Interfacing

Designed by-Yogesh Kumar 12

Mobile Remote Control System

Designed by-Yogesh Kumar 13

Microcontroller

Voice Chip

DTMF Decoder chip

Device No. 1 Device No. 2 Device No. 3

To/from Phone Jack (Output/Input)

Outputs

Data Access Arrangement Chip

SS Relay SS Relay SS Relay

MCU Electronic Circuit

Designed by-Yogesh Kumar 14

Project at a glance

Designed by-Yogesh Kumar 15

Want to ask ???

Designed by-Yogesh Kumar 16

Any doubts or queries……

Designed by-Yogesh Kumar 17