IR RECIEVER & TRANSMITTER

8/8/2019 IR RECIEVER & TRANSMITTER

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IR RECIEVER TSOP1733:

Description:

The TSOP1733 are miniaturized receivers for infrared remote control systems. IN diode

and preamplifier are assembled on lead frame, the epoxy package is designed as IR filter.The demodulated output signal can directly be decoded by a microprocessor. TSOP1733

is the standard IR remote control receiver series, supporting all major transmission codes.

Features:

Photo detector and preamplifier in one package

Internal filter for PCM frequency

Improved shielding against electrical field disturbance

TTL and CMOS compatibility


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Output active low

Low power consumption

High immunity against ambient light

Continuous data transmission possible (up to 2400 bps) Suitable burst length .10 cycles/burst

Here the IR receiver receives IR frequency from transmitter generates a bit

0 while IR frequency focused on the IR detector, generates bit 1 when there is no IR

signal. This IR data is given to the RXD pin of the micro controller used in the receiver.

Transmitter:

Normally the port maintains logic high state when the signal light is at OFF state;

it maintains logic 0 when it is at ON state. The program written in the micro controller

gets the data from the port pin transfers appropriate code to the serial buffer 89c52. The

serial buffer transmits the data to the receiver unit via TXD pin of the micro controller

with the following parameter the transmission speed is 300bps, data length is 8 bit, no of

stop bits is equal to 2, no parity. The 300bps is developed from the basic crystal

frequency 11.052MHz. The frequency is divided to 300bps with the help of internal timer


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counter register. The transmitted data is given to the IR modulator. Here we have used a

crystal oscillator 11.052MHz crystal, 33pf capacitor specified by the manufacturer

connected to pin XTL1 and XTL2. We have designed reset logic for active high reset

signal, 10f capacitor, 8.2K resistors i.e. connected to the RST pin of micro controller.

IR modulator:

The IR modulator is an Astable multivibrator generates 35 KHz frequency

while receiving a bit0 from the TXD pin of the micro controller. By receiving bit1 at pin4

i.e. RST of 555. The data from TXD pin of micro controller is inverted with the help of

BC547 transistor. Ultimately bit0 at the TXD pin of the micro controller generates 35

KHz IR frequencies, the frequency is emitted by the IR LED with the help of BC547

driver transistor, and its base is connected to 555 output.

V C C

V C C

V C C

V C C

+ 9 v

B C 5 4 7

1 0 K

1 0 / 1 6 v

S W ?

S W ?

?

S W ?

I R L E D ?

8 . 2 K

Y ?1 1 . 0 5 9 2

I R L E D 2

3 3 p f

4 1 4 8

4 7 E

2 2 2

1 0 k

4 1 4 8

U ?

L M 5 5 5

3

48

526

7

14 . 7 k

3 3 p f

U ?

A T 8 9 C 2 0 5 1

1

1 0

54

1 11 2

2 03

1 3

1 0 4

B C 5


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Receiver:

The receiver is having IR

photo diode and IR processing comparator

opamp. It has 3 pins, one is ground, other is

Vcc via 47 resistor & 10f capacitors the

network reduces Vcc by 1.5V safety voltage

is applied to IR receiver the 3rd pin is data pin

and is normally at high state when there is no

signal focused on IR receiver when there is

signal. This asynchronous data is given to

RXD pin of micro controller the data

received at RXD pi of the micro controller

converts into parallel subsequently stores in

serial buffer. The serial setting is same as the

setting of transmitter i.e. (300bps, 8bit, 1stop bit, no parity).

V C C

V C C

V C C U ?

A T 8 9 C 5 2

1 9

1 8

4

0

3

1

2 22 3

2 6

2

0

9

2 72 8

3 23 33 43 53 6

3 73 83 9

1 2

1 0

2 1C ?

3 3 p

C ?1 0 m f / 1 6 v

R ?

8 . 2 K

4 7 EI R R e s

12

31 0 / 6 3

Y ?

1 1 . 0 5 9 2

C ?3 3 p

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IR RECIEVER & TRANSMITTER