Motorola DCT6412 & Cambridge Soundworks AVS550 conflict

grcobb · Post by **grcobb** » Mon Jan 17, 2005 6:51 am

I have searched around and cannot find a solution to a conflict between the Motorola 6412 cable box and the Cambridge Soundworks AVS550 Rcvr/Amp (with DVD - Home Theater In-a-box).

I'm using a OFA 8811 remote and have configured it using a JP1 cable to operate both devices. When I press Ch+, Ch-, Page+, Page- and a few other keys when in Cbl mode, the volume on the AVS550 also changes (the sound goes down). After changing the channel several times, I can hardly hear it. One solution I have found is to press another button (AV2 or Audio In) on the AVS550 which seems to lock the volume so it is not changed when using the 8811 in Cbl mode.

I have configured the remote using KeyMoves to run the volume on the AVS550 when in cable mode with all other buttons running the DCT6412 cable box.

The Protocol and EFC codes are different for both boxes:.
The Cambridge Soundworks AVS550's are:
Protocol=NEC1, Main Device=8
EFC codes -- Vol+=165, Vol-=036.
The Motorola DCT6412 cable box EFC codes are:
Protocol=GI Cable
EFC Codes -- Ch+=140, Ch-=147, Page+=176, Page-=172

It is almost as if the AVS550 is picking up the GI Cable signal and changing the volume when it shouldn't.

Has anyone else seen this type of problem and can offer a solution.

Thanks in advance.

Post by **The Robman** » Mon Jan 17, 2005 7:40 am

Does this also happen when you use the original remotes?

grcobb · Post by **grcobb** » Mon Jan 17, 2005 8:10 am

Yes it does. The origonal cable remote also changes the Cambridge-Soundworks AVS550 volume. There is one strange thing I forgot to mention however.

The cable remote will change the volume on the AVS550 but pressing the volume buttons on the AVS550 remote will not change the channels on the DCT6412.

Post by **The Robman** » Mon Jan 17, 2005 10:07 am

The frequency and timings in the UEI versions of NEC and GI protocols are almost identical, even though the formats are different. However, I just downloaded a CCF for one of these Motorola PVR boxes and the real timings are slightly different. For example, the true IR frequency is 38.7khz, so I've got an idea for an experiment.

If we were to keep increasing the IR frequency gradually starting from 38.7khz, hopefully the Cambridge will stop responding before the Motorola does.

Before we start this, could you learn a few buttons from the Motorola remote, then post the IR file.

johnsfine · Post by **johnsfine** » Mon Jan 17, 2005 10:24 am

I remember a very similar issue in some thread about a Pronto. I don't recall what the two protocols were.

My evaluation of the issue at that time was that the end of one signal matched the beginning of the other, and the IR receiver was so stupid that once the beginning matched it didn't care that the signal ended.

My suggestion in that case was to add something to the end of the signal, that wouldn't matter to the device it was intended for, that would change its meaning (to something innocuous) for the device not intended.

That wasn't tried. I don't recall why. Probably the person with the issue left the thread.

Edit: got interrupted before I could finish typing:

I doubt Rob's idea of tweaking the frequency will work well. But it's a lot easier to try than tweaking the end of the generated signal, so it's worth trying.

grcobb · Post by **grcobb** » Mon Jan 17, 2005 10:40 am

I have uploaded the .IR file from my 8811 remote to the Diagnosis Area ("DCT6412 (Cable)/AVS550 (Rcvr) Conflict") that contains Learned Keys from the 2 remotes.

The keys are Ch+ & Page+ (DCT6412) and the Vol+ & Vol- (AVS550).

Thanks

Gary

Post by **The Robman** » Mon Jan 17, 2005 11:38 am

Could you provide a link please (as it saves having to go search for the file)

grcobb · Post by **grcobb** » Mon Jan 17, 2005 11:54 am

Try this one...

https://www.hifi-remote.com/forums/dload ... le_id=1224

Post by **The Robman** » Mon Jan 17, 2005 1:29 pm

Here's a couple of protocol upgrades you can try where I'm increasing the frequency in steps. Once you find that a frequcny doesn't work the Motorola box anymore, there's no point in trying the higher frequencies.

If the frequency that no longer controls the Motorols still changes the volume on the Cambridge, the experiment has failed because it means the Cambridge is more flexible than the Motorola. If this protocol also fails to work the Cambridge, then it might be worth trying protocols where the frequency changes in smaller steps. In this case, tell me which was the highest frequency that worked and I'll try creating some more protocols for you to try.

Upgrade Protocol 0 = 00 C4 (S3C8+) 38.5 khz
43 89 01 8B 12 CC 4D 00 08 00 FA 08 B6 00 FA 04
51 C3 3C 11 94 08 B6 20 11 08 03 F6 FF 36 08 04
F0 C0 56 C0 F0 04 04 C0 60 C0 56 C0 F0 06 C0 10
F6 FF 36 8D 01 46 1C 08 C0 C0 10 04 1A FA AF
End

Upgrade Protocol 0 = 00 C4 (S3C8+) 39 khz
42 87 01 8B 12 CC 4D 00 08 00 FA 08 B6 00 FA 04
51 C3 3C 11 94 08 B6 20 11 08 03 F6 FF 36 08 04
F0 C0 56 C0 F0 04 04 C0 60 C0 56 C0 F0 06 C0 10
F6 FF 36 8D 01 46 1C 08 C0 C0 10 04 1A FA AF
End

Upgrade Protocol 0 = 00 C4 (S3C8+) 39.5 khz
41 86 01 8B 12 CC 4D 00 08 00 FA 08 B6 00 FA 04
51 C3 3C 11 94 08 B6 20 11 08 03 F6 FF 36 08 04
F0 C0 56 C0 F0 04 04 C0 60 C0 56 C0 F0 06 C0 10
F6 FF 36 8D 01 46 1C 08 C0 C0 10 04 1A FA AF
End

Upgrade Protocol 0 = 00 C4 (S3C8+) 40 khz
40 84 01 8B 12 CC 4D 00 08 00 FA 08 B6 00 FA 04
51 C3 3C 11 94 08 B6 20 11 08 03 F6 FF 36 08 04
F0 C0 56 C0 F0 04 04 C0 60 C0 56 C0 F0 06 C0 10
F6 FF 36 8D 01 46 1C 08 C0 C0 10 04 1A FA AF
End

Btw, you have alot of un-used upgrades in that file. You will have to delete at least one of them to make room for this protocol.

grcobb · Post by **grcobb** » Mon Jan 17, 2005 2:32 pm

Here is what I did. Hopefully I didn't do the right thing because none of them had any effect on the problem.

1. Copied the text from your note.
2. Went to ir, Protocols tab, click Add the first time since 00 C4 was not there (clicked Edit every other time after highlighting 00 C4).
3. Pasted the text, closed the window and uploaded to the remote.
4. Went to the devices and made sure that the protocol for the Motorola was C4.

I went through all of the ones you suggested and the Ch+ key moved the channel on the Motorola box and the volume on aht AVS550 went down. After looking at the changes to each set, I also tried 39/83 (40.5mhz), 38/82 (41), 37/81 (41.5), 34/7E (43) , 30/7A (40mhz). Then I went the other way -- 47/8C (36.5) and 50/8F (35mhz).

I uploaded the last IR file that is in the remote. You can fine it at https://www.hifi-remote.com/forums/dload ... le_id=1226

Thanks. Any more suggestions?

Gary

Post by **The Robman** » Mon Jan 17, 2005 2:54 pm

Wow, you mean you ramped the freq up to 43 khz and both units still responded? Keep going higher, try jumping straight to 50 khz and if that works go to 60 khz. If 60 khz works then I've got to assume you're not testing it correctly because there's no way that a device programmed to look for 38 khx should respond to a freq that's so far off base.

Once you've found a freq that doesn't work, start coming back down again.

grcobb · Post by **grcobb** » Mon Jan 17, 2005 3:28 pm

I bumped it all the way to 60 (if I fugured the hex correctly) and it still works both devices. The first part of protocol C4 is:

Code: Select all

FF00:  18 5C       DB   18H, 5CH   <---the stuff I've been changing
FF02:  01	       DB   01H
FF03:  8B 12       JR   FF17H
FF05:  CC 4D       DB   CCH, 4DH

I must be doing something wrong. I had posted a new IR file I just downloaded from the remote that has the protocol set to these values if you want to see them to see what I'm doing wrong.

The link is https://www.hifi-remote.com/forums/dload ... le_id=1227

I couldn't see how to delete the other files.

Puzzling isn't it.

Gary

Post by **The Robman** » Mon Jan 17, 2005 4:42 pm

grcobb wrote:I bumped it all the way to 60 (if I fugured the hex correctly) and it still works both devices. The first part of protocol C4 is:
Code: Select all
FF00:  18 5C       DB   18H, 5CH   <---the stuff I've been changing
FF02:  01	       DB   01H
FF03:  8B 12       JR   FF17H
FF05:  CC 4D       DB   CCH, 4DH
I must be doing something wrong. I had posted a new IR file I just downloaded from the remote that has the protocol set to these values if you want to see them to see what I'm doing wrong. The link is https://www.hifi-remote.com/forums/dload ... le_id=1227

I couldn't see how to delete the other files.

Puzzling isn't it.

Gary

Yes, very. John, any ideas?

grcobb · Post by **grcobb** » Tue Jan 18, 2005 11:42 am

Rob,
I just spent about an hour walking between my computer and the tv, changing the frequency each time to see if I could find out the upper and lower ranges for the dct6412 and avs550. This is what I found:

dct6412 worked from 10 5A to FF FF
avs550 worked from 10 33 to FF FF

(these values are the first 2-bytes of the protocol for the dvt6412)

I'm now sure how that converts to the frequency, I'll let you do the math.

Not sure how this will help but thought I'd pass it along.

Gary

Post by **The Robman** » Tue Jan 18, 2005 11:48 am

Those results are totally surprising, I expected both devices to crap out once the frequency went more than a few khx above what they were expecting. But either way, as the Cambridge accepts a wider range of freqs, it pretty much rules out using freq to fix this.

Which brings us back to John's idea of inserting some extra meaningless code into the signal, in such a way that the TV will still respond but the receiver won't. However, looking at the signals, I can't see what the receiver is responding too. Even though the two protocols are very similar as far as freq, burst times and leadin times go, the actual signals generated appear to be different enough that there shouldn't be an overlap.

I'm hoping that John jumps in at this point to suggest how to proceed.