Jump to content
Flirc Forums

infrared remote signal standard?

Recommended Posts

Hi, I have an old Kloss 88 table radio that I'm partial to and would like to use as the speakers for my HDTV system.  (I need the FM as well.) The problem is I've lost the remote for it.  I recently bought a Flirc and I'm in the process of consolidating my remotes, but a profile cannot be found for the 88 in any of the several manufacturer-published lists I've seen.  A Google search comes up empty as well.

So my questions are, obviously the signal from any single remote keypress produces an infrared pattern and a learning remote will store that pattern in memory.  Well, why don't we, as advanced enthusiast consumers, have access to that pattern?   Let's say some guy out there does have the Kloss 88 remote and has taught his universal.   Why can't he extract and trade his patterns with me?   Is there some industry standard protocol for remotes that I don't know about?   If not why not?  If there was and there was some standard way to digitally describe a keypress, I could just look up the keypresses I need in some database and I could just upload them to my universal.

OK maybe this is part of the answer:  A keypress generates an ultimately analog signal.  A learning remote samples that signal, coverts it to digital, and stores the numbers in memory.  This is necessary since there is no such thing as analog memory.  Since many manufactures have different ways of sampling and digitizing the signal, no one numerical pattern exists for any given keypress. 

Can anyone speak to this?

Link to post
Share on other sites

This isn't really related to Flirc in anyway but the subject is exciting :) so I'll point you in some directions.

First of all I would like to recommend to you this forum: http://hifi-remote.com/forums/

I've learned a lot from there and I also helped reverse engineering one of the remotes (OneForAll URC-6440). There's a group of people there who are maintaining a lot of cool software. One of the programs available on the forum is the RemoteMaster which has been written to be able to configure remotes produced by UEI. These remotes are known as JP1 remotes. A lot of there remotes have a learn function and RemoteMaster is able to retrieve the learned signal data from them.

I don't know if this is universal for all the learning remotes or not but in the case of UEI/OFA remotes the learned signal is saved as a demodulated raw data. AFAIK the remote doesn't do a protocol guessing and decoding. That logic is included in the RemoteMaster tough and it can guess from the raw data the protocol used and decode it (as long as it is a known protocol). For example from raw data it can guess that the signal uses X protocol with Device ID Y and Subdevice ID Z and shows you the exact button code. You can use this data to prepare a device upgrade yourself - a device upgrade is a configuration block that describes a remote for a particular device, it contains info about the protocol, dev id, subdev id, list of available button functions and assignment of functions to each physical button on the remote.

I've used this to learn buttons from my LG Soundbar's remote (URC-6440 has been able to control the Soundbar but not all the buttons worked). I've then write down all the button codes from the original remote and I also started checking all the other codes if there are some other working codes that are not available on the original remote. For example I've found a discrete On and Off codes or discrete Source selection buttons. Having all that info I've created my own device upgrade for the Soundbar.

BTW sending random button codes to the device (assuming other parameters are set up properly) can be dangerous. I've also found some service functions (LG service probably has a service remote which these buttons). My Soundbar has a wireless subwoofer and by checking all the codes I've managed to disconnect the subwoofer from the main device and normal pairing procedure couldn't help. I don't even know how exactly I've restored it to working state as I've just started pressing more of the service buttons :P.

BTW2 you can also use a simple IR receiver called Igor: http://www.cesko.host.sk/girderplugin.htm. For it to work you also need a COM port (can be an USB-COM adapter). It just sends the demodulated RAW signal to the computer over serial port. You need some software to catch it on the other end and also some software that can guess IR protocol.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...