BIBIN JOHNSONBIBIN JOHNSON

ContentsContents

• What is Infrared (IR) ?

• IntroductionIntroduction• Characteristics and key featuresCharacteristics and key features

• IInfrared communication standardsnfrared communication standards

• How IrDA Transmission Works

• Conclusion and Future of the IConclusion and Future of the IrrDADA

What is Infrared (IR) ?What is Infrared (IR) ?(the prefix infra means `below‘)

The electromagnetic spectrum includes gamma rays, X-rays, ultraviolet, visible, infrared, microwaves, and radio waves. The only difference between these different types of radiation is their wavelength or frequency.

Visible

Micro wave

near-IRnear-IR mid-IRmid-IR Far-IRFar-IR

= 0

.75

m

Cannot see (human eye)

Infrared is usually divided into 3 spectral regions

0.8–5 m 5-40 m 40-250 m

Some animals can "see" in the infrared. For example, snakes in the pit viper family (e.g. rattlesnakes) have sensory "pits," which are used to detect infrared light. This allows the snake to find warm-blooded animals.

The primary source of infrared radiation is heat or thermal radiation. This is the radiation produced by the motion of atoms and molecules in an object. Any object which has a temperature above absolute zero (0 K) radiates in the infrared.

Landing space shuttle

personholding burning match

Cat

Infrared image of Orion

Human & vehicle at total darkness thermal image in white=hot mode

same image in Black=hot mode

Human Suspect climbing over fence at 2:49 AM in total darkness

Suspect attempting to burglarize vehicle at 1:47 AM in total darkness.

IntroductioIntroductionn

• The Infrared Data Association, often The Infrared Data Association, often referred to as IrDA, is a nonprofit referred to as IrDA, is a nonprofit organization whose goal is to develop organization whose goal is to develop globally adopted specifications for infrared globally adopted specifications for infrared wireless communication.IrDA was formed in wireless communication.IrDA was formed in 1994. 1994.

• It thrives today due to the hundreds of It thrives today due to the hundreds of corporate and individual members who corporate and individual members who volunteer their time and know-how to the volunteer their time and know-how to the continued development of IrDA applications continued development of IrDA applications and specifications. and specifications.

IInfrared communication nfrared communication standardsstandards

• IrDA-DataIrDA-Data defines the standard for defines the standard for the wireless, two-way infrared data the wireless, two-way infrared data transmission between two devices transmission between two devices

• It It consists of a set of mandatory consists of a set of mandatory protocols: PHY (Physical), IrLAP (Link protocols: PHY (Physical), IrLAP (Link Access), and IrLMP (Link Access), and IrLMP (Link Management).Management).

IInfrared communication nfrared communication standards(CONT)standards(CONT)

• IrDAIrDA is the infrared standard that is the infrared standard that allows wireless peripherals such as allows wireless peripherals such as keyboards, mouse, game pads, keyboards, mouse, game pads, joysticks, and other pointing devices to joysticks, and other pointing devices to interact with many types of host interact with many types of host devices. Host devices include PCs, devices. Host devices include PCs, home appliances, game consoles, and home appliances, game consoles, and TV/Web set top boxes.TV/Web set top boxes.

BBenefits for IrDA-standardenefits for IrDA-standard

• Offers a universal wireless standard for Offers a universal wireless standard for connecting all portable infrared-enabled connecting all portable infrared-enabled devices devices

• Easy, effortless implementation Easy, effortless implementation • Economical alternative to other connectivity Economical alternative to other connectivity

solutions solutions • Reliable, high speed connection Reliable, high speed connection • Safe to use in any environmentSafe to use in any environment,, can even be can even be

used during air travel used during air travel • Allows PC’s and non-PC’s devices to Allows PC’s and non-PC’s devices to

communicate with each other communicate with each other

Characteristics and key Characteristics and key featuresfeatures

• An IrDA infrared connection is An IrDA infrared connection is established solely by a directed established solely by a directed infrared beam, for bi-directional half-infrared beam, for bi-directional half-duplex communications. The lowest duplex communications. The lowest signaling rate is 9,600 bps, and the signaling rate is 9,600 bps, and the highest currently specified is 16 highest currently specified is 16 Mbps.Mbps.

Characteristics and key Characteristics and key features(CONT)features(CONT)

• Nevertheless, most devices available Nevertheless, most devices available today operate at a maximum of 4 today operate at a maximum of 4 Mbps. The range of the line-of-sight Mbps. The range of the line-of-sight connection is typically 2 metersconnection is typically 2 meters..

Characteristics and key Characteristics and key features(CONT)features(CONT)

• There is also a low power version There is also a low power version available with a limited range objective available with a limited range objective of 20 cm, but at 10 times less power of 20 cm, but at 10 times less power consumption.consumption.

• IrDA connections are suitable for point-IrDA connections are suitable for point-to-point and even point-to-multipoint.to-point and even point-to-multipoint.

• IrDA is very popular with portable IrDA is very popular with portable devices, such as notebooks, handheld devices, such as notebooks, handheld computers, digital cameras, electronic computers, digital cameras, electronic books, toys, and watches.books, toys, and watches.

DIFFERENT TYPESDIFFERENT TYPES

• SIR Slow infrared: (IrDA 1.0 SIR Slow infrared: (IrDA 1.0 Standard), which Standard), which hashas aa capability to capability to transmit data at 9.6 kbps to 115.2transmit data at 9.6 kbps to 115.2

• FIR Fast infrared :(IrDA 1.1 FIR Fast infrared :(IrDA 1.1 Standard), which is the capability to Standard), which is the capability to transmit data up to 4 Mbits/sec. transmit data up to 4 Mbits/sec.

• VFIRVFIR Very fast infrared :Very fast infrared :Upto Upto 16 Mbps16 Mbps

Difference between Difference between direct direct infrared, diffuse infrared, and infrared, diffuse infrared, and radio frequency?radio frequency?• Direct infraredDirect infrared is a point-to-point, typically is a point-to-point, typically

one-to-one communication. Which requires one-to-one communication. Which requires line of sight and is a secure form of data line of sight and is a secure form of data transmission and reception.transmission and reception.

• Diffuse infraredDiffuse infrared allows many-to-many allows many-to-many connections, does not require direct line of connections, does not require direct line of sight and can be uni-directional or bi-sight and can be uni-directional or bi-directional. Since it is based on visible light, it directional. Since it is based on visible light, it is a secure form within a room. is a secure form within a room.

• Radio frequencyRadio frequency is not secure in that it can is not secure in that it can penetrate through walls and is subject to penetrate through walls and is subject to uncontrolled interference. It is typically higher uncontrolled interference. It is typically higher in power consumption than directed infrared in power consumption than directed infrared and requires FCC certification. and requires FCC certification.

How IrDA Transmission Works

• The IrDA transmission require 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 UART. All transmissions must be started at this frequency to enable compatibility.

How IrDA Transmission Works(cont)

•Higher speeds require special interfaces which operate at 1.152 Mbit/s

• The fastest data rate supported by IrDA is 4.0 Mbit/s operating with 125–ns pulses.

• The TSOP1736 is a 3 pin device that receives the infrared bursts and gives out the demodulated bitstream at the output.

Infrared Photo Transtor - TK69 TSOP1738

Phillips RC5 Phillips RC5 • Most audio and video systems are equipped Most audio and video systems are equipped

with an infrared remote control.with an infrared remote control.• A common used standard protocol for A common used standard protocol for

infrared data communication is the RC5 infrared data communication is the RC5 code, originallydeveloped by Phillips. code, originallydeveloped by Phillips.

• This code has an instruction set of 2048 This code has an instruction set of 2048 different instructions and is divided into 32 different instructions and is divided into 32 addressaddress of each 64 instructions. of each 64 instructions.

• Every kind of equipment use his own Every kind of equipment use his own address,so this makes it possible to change address,so this makes it possible to change the volume of the TV without change the the volume of the TV without change the volume of the volume of the Music system.Music system.

Phillips RC5Phillips RC5

The transmitted code is a dataword wich The transmitted code is a dataword wich consists of 14 bits consists of 14 bits of which,of which,

• 2 2 are are startstart bits for the automatic gain bits for the automatic gain control in the infrared receiver. control in the infrared receiver.

• 1 toggle bit (change everytime when a 1 toggle bit (change everytime when a new button is pressed on the ir new button is pressed on the ir transmitter) transmitter)

• 5 address bits for the system5 address bits for the system address address

• 6 instruction6 instruction bits for the pressed keybits for the pressed key

Phillips RC5Phillips RC5

• The duration time of each bit is equal toThe duration time of each bit is equal to 1,778 1,778 ms and the total time of a full ms and the total time of a full RCRC5 code is 5 code is 24,24,888899 ms. ms.

FutFutureure of I of IrrDADA

• Infrared port will soon be seen in Infrared port will soon be seen in copiers, fax machines, overhead copiers, fax machines, overhead projectors, telephones, bank ATM's, projectors, telephones, bank ATM's, credit card readers, game controls, credit card readers, game controls, and headsets…etc. and headsets…etc.