USB-UIRT Forum

Guest

I've been using the sample UIRT application, and writing my own simple application, to learn and transmit IR codes for a remote control and receiver that use Philips RC-5. However, the learning does not always produce the same codes for a particular key, and the transmission is not 100% reliable. Does anyone have a mapping from RC-5 codes to UIRT raw format (UUIRTDRV_IRFMT_UUIRT), or a list of the mapped codes?

Frank Mc Alinden · Joined: 28 Aug 2004 Posts: 50 Location: Melbourne Australia

Hi
The RC5 IRFormat has whats known as a toggle bit which changes state each time a button is pressed...So if you press the same button twice one ir signal will have the toggle bit set and the other will have it reset....so the same button gives two slightly different codes.......
HTH
Frank

Guest · Posted: Fri Nov 05, 2004 10:11 am Post subject:

Thanks. I had briefly read that in a description of RC-5, but not really thought about it's significance(!!) I can see that I need to take that into account in my program. However, I find that I get more than 2 different codes for the same key, so it's not obvious which is which. I don't suppose you have a (reliable) pair of example UIRT raw codes corresponding to a single RC-5 code?

Frank Mc Alinden · Joined: 28 Aug 2004 Posts: 50 Location: Melbourne Australia

Hi
How do you generate and save raw usb uirt codes ??? do you have to use Girder ???....
Frank

Guest · Posted: Fri Nov 05, 2004 10:42 am Post subject:

No. I have tried the sample application ("trydrv"), girder, and my own small program, which does something very similar to the sample app. I get slightly different codes from girder (have the first few character missing), but they seem to have the same effect when I use them in the call to UUIRTTransmitIR(). E.g. for a key that produces RC-5 code 0x3726, I sometimes get (from UUIRTLearnIR()) a code of:
"F45R06D6202020202020202020204020204040202040202040"
and sometimes:
"F45R06D620204040202020204020204040202040202040"
and sometimes others.

Unfortunately, I don't have the USB-UIRT device with me today, so I can't try it out Sad

mwtb · Joined: 16 Dec 2004 Posts: 4

Has anyone got any insight into how to apply the toggle bit to RAW codes? In theory, fixing the parity problem is just a case of flipping the bit on every send, but I don't know where to change the code.

Guest · Posted: Mon Apr 03, 2006 8:09 pm Post subject: Any update on this issue?

If anyone resolve this issue, could you please post your resolution here?
Thanks in advance.

mwtb · Joined: 16 Dec 2004 Posts: 4

I posted a description of how to do it here