Infrared Communication basics | IrDA | IR,Infrared tutorial

This page of tutorials section covers Infrared Communication (IrDA) basics. The IR-Infrared tutorial covers Infrared features, IR network operation, IR spectrum, Infrared applications, Infrared advantages and disadvantages.

Introduction: As we know infrared (IR) devices are used in wireless personal area networks spanning coverage range of about 30 feet which involves laptops, computers, PDAs and cellular phones. It has frequency range between 300 GHz and 400 THz and wavelength range between 1 mm and 750 nm.

As we know Infra means below and red refers to red color light. Hence the name Infrared stands for light which has low frequency or long wavelength than red light spectrum.

Features Infrared Support
Frequency Between 300 GHz and 400 THz
Wavelength Between 1 mm to 750 nm
Distance about 10-30 meters
Data Rate Serial infrared supports 300 to 115200 bps
Fast Infrared supports about 4 Mbps
Modulation PPM (Pulse Position Modulation)

IR Spectrum of operation

light infrared-IR spectrum

Figure-1 depicts light signal spectrum which mentions infrared (IR) spectrum also. As shown IR spectrum falls between 300 GHz to 400 THz frequency region. Infrared spectrum is further divided into near infrared, mid-infrared and far-infrared bands.
Refer IR spectrum table➤.

Infrared Devices-LED and Laser

There are two infrared components used in IR devices viz. LED (light Emitting Diode) and Laser Diode. LED has wider transmission beam and suitable for diffuse mode of configuration as described below. It is most commonly used. It is used as transmitting element in Infrared communication.

The other component is Laser Diode which has more focused beam. Moreover it is more efficient optical element used in receiving part of Infrared communication system.
Refer LED vs Laser➤.

Many infrared devices such as remote control, PDAs and Laptops follow rules defined by IrDA. IrDA stands for Infrared Data Association.

How Infrared Communication Network Works

Infrared communication modes
Fig-1:Infrared Communication Network

• There are two configuration modes in infrared viz. point to point communication and diffuse communication.
• In point to point communication, both transmitter and receiver infrared devices should be placed in line of sight of each other and there should not be any obstacles (e.g. walls) in between them.
• In diffuse communication, transmitter and receiver IR devices should be kept close to each other but they need not be in the straight line of sight. Most commercial IR products will operate efficiently within 15 degree of each other.
• Infrared detector operates at 38.5 KHz frequency of operation.

Infrared-IR Advantages

Following are the advantages of Infrared:
• It is secure way of communication as communication is point to point or line of sight. It is not feasible for intruder to come in between and hack the data.
• IR devices have low power consumption and hence battey will last for longer period.
• IR devices are less costly.

Infrared-IR Disadvantages

Following are the disadvantages of Infrared:
• As it is line of sight, it is difficult to control things not in line of sight of transmitting IR control device.
• It can control one device at a time.
• Maximum data transfer rate is about 4 Mbps
• The device should be kept stable during the data transfer mode.
• hard obstacles (such as doors, walls), bright sunlight, smoke, dust and fog affects Infrared communication.
• Even though we can not see Infrared waves, it can damage eyes if transmitted with more signal power.

Infrared Communication Applications

Following are the applications of Infrared communication:
• PDAs
• Phones
• Organizer
• Printers
• Cameras
• laptops and notebooks
• TV Remote controls
• IR Spectroscopy
• IR photography

This Infrared tutorial is useful for beginners in infrared communication domain.


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