tv remote related question

How remotes of each TV s are different ?
Can i make one expeditiously for my TV ?
i seen some re mots work different TV
please give the information regarding it
thanx

Some TV remotes use RC-5 protocol but Sony TV use SIRC protocol.

Visit SB-Projects: IR remote control: SIRC protocol for more

Also Visit

HowStuffWorks "How Remote Controls Work"

Consumer IR - Wikipedia, the free encyclopedia
SB-Projects: IR remote control: NEC protocol
SB-Projects: IR remote control: SIRC protocol
SB-Projects: IR remote control: Philips RC-5

Can i bulid a remote for a tv ?

Yes you can.

The TV will only respond to codes it recognizes though so you must duplicate the codes sent by the real remote control unit. Products use different rates and variations of IR flashes so they only respond to one remote and are not controlled by one for a different appliance. You need to find out what variation your product expects, the links given earlier will explain the systems normally used.

Brian.

Programmable remotes like Logitech Harmony remotes have an online database to tell their remote the correct coding format for many products.

As a last resort, the Harmony remotes also have a learning mode which reads another remote's code. It is not perfectly accurate in reading another remotes but does a pretty good job, usually good enough to have the function work properly. The toughest job is to read the high frequency carrier which can be between 30 kHz to 60 kHz.

To do a single key function to multiple devices it sends their codes serial. For example to turn on the HDTV, Hometheater amp, and satellite receiver it sends the power command for one then another, then another. It may also select the correct amp input selection or other setup functions. It does this relatively fast so you don't notice the delay.

It is a good PIC microcontroller project.