AutomationCommunication

TELECOM SWITCH

TELECOM SWITCH

                   TELECOM SWITCH

Aim:

To Control Home appliances through Mobile Phone

 

Working Principle:

To acquire Signals from Mobile phone to control various home Appliances such as T.V ,Fridge ,A.C etc. . .

 

Block diagram:

TELECOM SWITCH

Block diagram Explanation:

Here we are designing a System which will receive key tones from mobile and control the home appliance from long distances. For this the user has to call the receiving phone, after picking, depending on the number pressed by the user the receiving phone will generate the tones which are interfaced to µC via 3.5mm Jack. For this purpose we are interfacing a DTMF IC which will decode the tones and convert them into BCD digits. The µC will then compare these digits and switch ON/OFF the relays according to the look up table stored in the program.

  • Read the Tones from DTMF IC.
  • Compare the BCD digits to the look up table
  • Display the Digits on LCD
  • Is Digit= 1? Yes Turn ON relay1
  • Is Digit= 2? Yes Turn OFF relay1
  • Is Digit= 3? Yes Turn ON relay2
  • Is Digit= 4? Yes Turn OFF relay2
  • Is Digit= 5? Yes Turn ON relay3
  • Is Digit= 6? Yes Turn OFF relay3
  • Loop

 

Hardware Features:

  • µC : PIC 16F877A
  • DTMF: 8870
  • 5 mm jack
  • LCD: 16*2 , 100 ma , Alphanumeric Display
  • Relay: 12v , 230v ,Single change over
  • Power Supply: 5V, 750 ma current.

 

Software Features:

µC programming: C

MPLAB IDE compiler, PIC Flash Programmer

 

Component List:

Sno. Component Name Quantity
1 µC 16F877A 1
2 LCD 16*2 1
3 Diode 1N4007 7
4 LM 7805 1
5 Crystal 11.0592 MHz 1
6 33 pf paper cap 2
7 0.1 µf Paper cap 4
8 10 µf Electrolytic cap 1
9 1000µf Electrolytic cap 1
10 10 kohm ¼ watt 3
11 150 pf paper cap 1
12 100Kohm 2
13 100Kohm pot 1
14 0.01µf 1
15 3.74Mhz 1
16 3.5mm Audio Jack 1
17 Relay 12v 10A 3
18 BC 547 3
19 2.2 Kohm ¼ watt 3
20 2 pin relimate conn. (M+f) 2
21 16 pin relimate conn. (M+f) 1
22 Resistance strip 10k 9 pin 1

 

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