2. 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
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3. 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.
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4. Block diagrams
INPUT PROCESS PROCESS
SYSTEM FUNCTION
You Have
OUTPUT
You Want
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6. 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.
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7. Need of Automation
1. Saves time When: you are in a traffic jam
2. Save money (Long run) on the highway
3. Self Maintenance What: You set microwave
oven in a slow cooking mode
4. Security
5. Makes life easy
Oven
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8. Mobile Network & Remote Control
SMS Based DTMF-
DTMF Based High Compatibility with all cell MS
GSM Data logging phone models
Very cheap ,Easy to implement
BTS GSM / CDMA
NETWORK
BTS
8 MS
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9. 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.
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10. 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.
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11. DTMF to BCD decoding
3.5 mm Jack
3.5 mm audio
connector
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13. Mobile Remote Control System
DTMF Decoder chip
To/from Phone Jack
(Output/Input)
Data Access
Arrangement Chip
Voice Chip
Microcontroller
Outputs
SS Relay SS Relay SS Relay
Device No. 1 Device No. 2 Device No. 3
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