clone for Comcast remote control only partly works

[danz]

I'm having trouble trying to make a remote control for a TV and a Comcast cable box (DCH70), using an Arduino Uno rev3.

I can make the TV turn on/off just fine now, using Ken Shirriff's IR library, but the cable box behaves weirdly, in that I can get it to turn on, but it then goes off again in a couple of seconds. (And this is NOT what happens with the real remote, it turns the cable box on until I turn it off.)


His library worked fine to decode the TV's remote, because it actually decoded the protocol used, and gives the coded data too, so I can then send the commands using the correct protocol; but his library couldn't recognize what the Comcast remote is putting out. So, after trying to tweak the raw data his library provided, and then looking all over the internet for any relevant info, I went back to the Raw IR decoder sketch from adafruit, https://github.com/adafruit/Raw-IR-decoder-for-Arduino , and it behaves exactly the same: turns the cable box on, but it goes off in a couple of seconds.

I've seen some suggestions that the Comcast remote uses an XMP protocol, though I don't see how to use that info, and I've found some sites which seem to give codes, but they are essentially the same as what I decode myself, and work exactly similarly.

Here's a sample of raw on/off IR signals I found, at
https://help.ubuntu.com/community/Motor ... nge_Script


name: power
9050 4400 550 2200 550 4400
550 2200 550 4400 550 2200
550 2150 550 2200 550 2200
550 2150 550 2200 550 2200
550 2150 550 2200 550 4400
550 4450 550 2150 550


Which is similar to what I get when I decode the remote's IR myself. As far as I can tell, the numbers are pairs of duration of 38khz carrier on & off, with 9050/4400 being a header, 550/2200 being a "mark" (one), and 550/4400 being a "space"(zero).

Any help or additional info would be appreciated.

Dan

[danz]

Here's another site that I found with some info about the IR data sent by Comcast/Motorola DCH70, in case it might help:
http://permalink.gmane.org/gmane.comp.h ... .lirc/8108

And here's some of that data:

header 9036 4424
one 556 2185
zero 556 4424
ptrail 556
gap 100025
toggle_bit 0

begin codes
power 0x000000000000AFF9
rew 0x00000000000087F7
play 0x00000000000027FD
ffwd 0x00000000000047FB
stop 0x000000000000C7F3
pause 0x00000000000007FF
rec 0x00000000000073FC
skipback 0x000000000000C3F7
mydvr 0x00000000000043FF
live 0x00000000000083F0

Seeing all those zeros in the hex data, I did try putting a series of the 556 4424 (= zero) carrier on/off values in the sender sketch, which did nothing at all to the cable box, but I only put 12 of those sets in front of the power data, not realizing 'till later that each zero in the hex meant '0000', or 4 sets of zero, needed 12 times, and I didn't try that as it seemed too far off the wall to make sense.

And I had earlier tried telling it to output at 56 Khz, in a sketch that did turn the box on briefly, as the person that sent that info in said they had to do that to make it work, but it still just turned on briefly, not sure why it even worked at that frequency.

I sure hope SOMEONE has succeeded in making a clone of the Comcast remote and can help me!

Dan

[DavidCDean]

I'm working on something similar, did you ever figure out a reliable control sketch for comcast boxes?