China G-box

jkgtw · Post by **jkgtw** » Thu Jun 16, 2011 2:53 am

Hi

I just got other TV box(G-box) and I don't know how to decode it?
remote's IR file:
http://www.hifi-remote.com/forums/dload ... le_id=9695

Please help me decode to RM.

Thanks,

Post by **vickyg2003** » Thu Jun 16, 2011 6:32 am

Make sure you have all your tools up to date. This is the XMP protocol and it requires the latest and greatest tools to accomplish the upgrade.

JP1 remotes do a very poor job of capturing XMP, since there are so many timing pairs to this hex based signal. You really need something like the widget to do a good capture, but Graham has done some mathematical gymnastics to try to figure out what the JP1 remote meant to record, but this is not always going to be correct. It will require some trial and error on your part.

From looking at the signals I can see these are XMP-1 style. If you widen the column called "protocol" you'll see a long hexidecimal number. The 00 at the end means the OBC is in the previous byte. That's what makes this xmp-1 instead of xmp-2. When I look at 02.ir I see the obc's for the up, down, left, right are 21h,22h,23h,24h.

Unfortunately that exhausts my xmp knowledge, you'll have to wait until 3fg or Rob chime in with the rest of this, or you can read the thread where the XMP protocol was discussed
http://www.hifi-remote.com/forums/viewtopic.php?t=10773

Post by **The Robman** » Thu Jun 16, 2011 1:59 pm

Try this...
http://www.hifi-remote.com/forums/dload ... le_id=9697

If it doesn't work, try changing the device code from 26 to 27 (leaving the sub-device unchanged at 33)

Post by **vickyg2003** » Thu Jun 16, 2011 3:56 pm

Hey Rob, I see that you picked 26 or 27 for the 1A or 1B that followed the 44, but where does the 33 come from? I used to know 3fg explained this to me more than once, but I can't recall

Post by **The Robman** » Thu Jun 16, 2011 8:38 pm

You could see that the fixed data shows as either "2B 1F 44 1B" or "2A 1F 44 1A". Neither of these is really valid, it should be either "2B 1F 44 1A" or "2A 1F 44 1B" based on the checksum rules.

Anyway, you can see that the main device code comes from the 4th byte. The sub-device code is a combination of the 1st nibble and the 3rd nibble (ie, the 2 and the 1 in "2B 1F 44 1A". If you put them together you get hex "21" which is decimal 33. The "44" byte is what we call the OEM code.

Post by **vickyg2003** » Fri Jun 17, 2011 8:42 am

The Robman wrote:. The sub-device code is a combination of the 1st nibble and the 3rd nibble (ie, the 2 and the 1 in "2B 1F 44 1A". If you put them together you get hex "21" which is decimal 33. The "44" byte is what we call the OEM code.

Thanks Rob, I don't know why I can't remember that,

.

That is just the information I was looking for.