Infrared Laser Pointer
Mutalip KURBAN
• Introduction
• Characteristics and key features
• infrared communication standards
• How IrDA Transmission Works
• Conclusion and Future of the IRDA
Introduction
• The Infrared Data Association, often referred to
as IrDA, is a nonprofit organization whose goal
is to develop globally adopted specifications for
infrared wireless communication. Celebrating its
ten-year anniversary, IrDA was formed in 1994.
It thrives today due to the hundreds of
corporate and individual members who volunteer
their time and know-how to the continued
development of IrDA applications and
specifications.
Introduction(cont)
IrDA takes a layered protocol approach
specifying several layers of protocols
including
1- IrPHY (physical layer),
2- IrLAP (link access protocol) and
3- IrLMP (link managment protocol).
Characteristics and key features of the IrDA
connection
• An IrDA infrared connection is established
solely by a directed infrared beam, for bidirectional half-duplex communications.
The lowest signaling rate is 9,600 bps,
and the highest currently specified is 16
Mbps.
Characteristics and key
features(CONT)
• Nevertheless, most devices available today
operate at a maximum of 4 Mbps. The
range of the line-of-sight connection is at
least 1 meter, but, typically, 2 meters can
be reached.
Characteristics and key features(CONT)
• There is also a low power version available
with a limited range objective of 20 cm,
but at 10 times less power consumption.
IrDA connections are suitable for point-topoint and even point-to-multipoint. IrDA is
very popular with portable devices, such
as notebooks, handheld computers, digital
cameras, electronic books, toys, and
watches.
SIR, FIR,VFIR
SIR Slow infrared: (IrDA 1.0 Standard),
which is the capability to transmit data at
9.6 kbps to 115.2 Official IrDA definition is
serial infrared
• FIR Fast infrared :(IrDA 1.1 Standard),
which is the capability to transmit data up
to 4 Mbits/sec.
• VFIRVery fast infrared :16 Mbps
infrared communication standards
• IrDA-Data defines the standard for the
wireless, two-way infrared data
transmission between two devices and
consists of a set of mandatory protocols:
PHY (Physical), IrLAP (Link Access), and
IrLMP (Link Management).
infrared communication
standards(CONT)
• IrDA-Control is the infrared standard
that allows wireless peripherals such as
keyboards, mouse, game pads, joysticks,
and other pointing devices to interact with
many types of host devices. Host devices
include PCs, home appliances, game
consoles, and TV/Web set top boxes.
infrared communication
standards(CONT)
The benefits for IrDA-standard infrared connection technology
includes,
• Offers a universal wireless standard for connecting all portable
•
•
•
•
•
•
•
infrared-enabled devices
Easy, effortless implementation
Economical alternative to other connectivity solutions
Reliable, high speed connection
Safe to use in any environment; can even be used during air travel
Eliminates the hassle of cables
Allows PC’s and non-PC’s devices to communicate with each other
Enhances mobility by allowing users to simply “plop and connect”
What is the difference between direct infrared, diffuse
infrared, and radio frequency?
• Direct infrared is a point-to-point, typically one-to-one
communication. Which requires line of sight and is a secure form of
data transmission and reception.
Hoya IrDA-standard wireless infrared solution is an example of
direct infrared.
Diffuse infrared allows many-to-many connections, does not
require direct line of sight and can be uni-directional or bidirectional. Since it is based on visible light, it is a secure form
within a room. Financial trading floors are an example of diffuse
infrared.
Radio frequency is not secure in that it can penetrate through
walls and is subject to uncontrolled interference. It is typically
higher in power consumption than directed infrared and requires
FCC certification.
How IrDA Transmission Works
• The transmission in an IrDA–compatible mode
•
(sometimes called SIR for serial IR) uses, in the simplest
case, the RS232 port, a built–in standard of all
compatible PCs. With a simple interface, shortening the
bit length to a maximum of 3/16 of its original length for
power–saving requirements, an infrared emitting diode is
driven to transmit an optical signal to the receiver.
This type of transmission covers the data range up to
115.2 kbit/s which is the maximum data rate supported
by standard UARTs (see figure 1). The minimum demand
for transmission speed for IrDA is only 9600 bit/s. All
transmissions must be started at this frequency to
enable compatibility. Higher speeds are a matter of
negotiation of the ports after establishing the links.
How IrDA Transmission Works
(cont)
• Higher speeds require special interfaces
which operate at 1.152 Mbit/s and use a
similar pulse–shortening process as in the
RS232–related mode, but with a pulse
reduction to of the original pulse length.
The fastest data rate supported by IrDA is
4.0 Mbit/s (often called FIR), operating
with 125–ns pulses in a 4–PPM (PPM =
Pulse–Position Modulation) mode.
AT89C55WD
The AT89C55WD is a low-power,
high-performance CMOS 8-bit
microcontroller with 20K bytes of
Flash programmable read only
memory and 256 bytes of RAM.
The device is manufactured using
Atmel’s high-density nonvolatile
memory technology and is
compatible with the industry
standard 80C51 and 80C52
instruction set and pinout.
Infrared Photo Transtor - TK69
TSOP1738
• The TSOP1736 is a 3 pin
device that receives the
infrared bursts and gives
out the demodulated
bitstream at the output.
Phillips RC5
• Most audio and video systems are equipped with
an infrared remote control.A common used
standard protocol for infrared data
communication is the RC5 code,
originallydeveloped by Phillips. This code has an
instruction set of 2048 different instructions and
is divided into 32 addressof each 64 instructions.
Every kind of equipment use his own address,so
this makes it possible to change the volume of
the TV without change the volume of the hifi
Phillips RC5
• The transmitted code is a dataword wich
•
•
•
•
consists of 14 bits and is defined as:
2 startbits for the automatic gain control in the
infrared receiver.
1 toggle bit (change everytime when a new
button is pressed on the ir transmitter)
5 address bits for the systemaddress
6 instructionbits for the pressed key
Phillips RC5
• The duration time of each bit is equal to
1,778 ms, and the total time of a full rc5
code is 24,778 ms.
Futer of IRDA
• Infrared port will soon be seen in copiers,
fax machines, overhead projectors,
telephones, bank ATM's, credit card
readers, game controls, and headsets,
…etc.
•