Re: What is an Infra Red "Device Code"?

[nobody@xxxxxxxxxxxx (Dave Houston)]

You are conflating two separate concepts.

There are a limited (although quite large) number of IR protocols which is
the overall scheme for transmitting the information. Then, within each
protocol, there are the individual codes the manufacturers assign to each
device and then to each function.

One of the oldest protocols was developed by NEC and it is in use by many
different manufacturers. You can find the details of the NEC protocol in
this datasheet (the site appears to be down right now).

     http://www.cpcares.com/pdf/UPD6121G-001.PDF

It's designed to incorporate a manufaturer's ID (assigned by NEC and called
a "custom" code) and a function code. In this way many manufacturers could
use the same protocol without interfering with each other. X-10 even uses
the NEC protocol to send RF with its handheld remotes.

Here's a link that explains several protocols.

     http://www.xs4all.nl/~sbp/knowledge/ir/others.htm

mr_ravi_patil@xxxxxxxxx wrote:

>
>Frank Olson wrote:
>> mr_ravi_patil@xxxxxxxxx wrote:
>> > What is an IR device code? (I am reading a manual for an  IR blaster).
>> > http://www.innotechsystems.com/spitfire-ii-device-codes.pdf
>> >
>> > So in the case of TV, each TV manufacturer (Sony, Sanyo,etc) uses
>> > different IR protocols to respond   remote control commands such as
>> > "channel up" ?
>> >
>> > Is that the idea?
>> >
>>
>>
>> Correct.  You wouldn't want to change channels on your TV whenever you
>> toggle your cable box or VCR now would you??  :-)
>
>
>That would not be good. But it would be simpler if all TV manufacturers
>folowed the same IR command for "channel up", etc.
>
>The only problem I could see with that is if you have 2 different
>brands of TV and wanna change the channel on just one.