While working with Infrared signals, we should also know that there are several Infrared communication protocols available on the market. These protocols are collectively referred to as Consumer Infrared (CIR).

Unlike internet TCP/IP packet transmissions, Infrared transmissions are an unregulated area. Over the years, electronics device manufacturers have defined and implemented their own protocols to transmit and receive Infrared signals. This was done to avoid interference in the cross operation of electronic devices placed side by side. For example, a Phillips DVD player with a Samsung TV - operating their individual remote controls should not interfere with the other device accidentally. In other words, we will not be able to increase the volume of a Samsung TV set with a remote control that works with a Panasonic TV set and vice-versa. Thus, IR protocols play a very important role.

For example, many Japanese manufacturers follow the NEC protocol for Infrared communications, whereas, European players like Phillips would have their own standard Infrared protocol. Some manufacturers like Sony have developed a proprietary protocol called S-Link. Similarly, there are many protocols in use today. IR protocols are an advanced topic, hence we will focus on the basics in this chapter.

In the latter half of this chapter, we will learn using appropriate protocols for transmitting IR signals to control devices of our choice.