Towards the goal of a truly universal IR remote control

Like breaking a combination lock you need a "tell " to work on. Assuming a piece of kit, impossible to get a remote control for and "universal " remotes do not register any change to the otherwise dead kit. If you broke into a ground or supply line to the microcontroller and monitored the supply current , would there be staged changes of current when exercised by various , but vast majority wrong, IR signals? ie simple swept 30 to 50 KHz oscillator source would you pick up on say

38KHz as the basic required "carrier" frequency ? Varying mark/space of gated pulses at that "carrier" f, would you pick up on the correct mark/space ? Then would there be a recognisable respone to various random "nibbles" that are parts of the required coding ?
Reply to
N_Cook
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To make a long story short -- no. It doesn't work that way. Simply reading the IR receiver's response to the wrong codes isn't going to tell us what the correct codes are.

It would have helped if you told us the make and model. Many products use the codes of their manufacturer, not the company that sells them.

And PLEASE learn how to write simple, clear sentences. It's worth the trouble.

Reply to
William Sommerwerck

g

William I think that what you wrote to Mr. Cook is really very insulting. Some people, and very intelligent ones at that just have a little trouble with the written word, and other seemingly simple tasks. My son is 28 and is a design engineer with Velcro. He was born with a form of dyslexia which among other things affects directionality. He still has trouble recognizing his left and right, and probably will all his life. I receive job applications from professional people at times that are absolutely appalling. Believe me that I was no English major either. However that is certainly no barometer of a person's capabilities, or intelligence for that matter. None of us are perfect, and if that is what you desire, then perhaps you should pick and choose a bit more carefully to whom you communicate with on this group. Lenny

Reply to
klem kedidelhopper

And PLEASE quote sufficient pieces of the post to which you are replying. It's worth the trouble.

Reply to
Allodoxaphobia

William I think that what you wrote to Mr. Cook is really very insulting. Some people, and very intelligent ones at that just have a little trouble with the written word, and other seemingly simple tasks. My son is 28 and is a design engineer with Velcro. He was born with a form of dyslexia which among other things affects directionality. He still has trouble recognizing his left and right, and probably will all his life. I receive job applications from professional people at times that are absolutely appalling. Believe me that I was no English major either. However that is certainly no barometer of a person's capabilities, or intelligence for that matter. None of us are perfect, and if that is what you desire, then perhaps you should pick and choose a bit more carefully to whom you communicate with on this group. Lenny

The most-insulting way I could treat Mr Cook would be to ignore his problem, to pretend it doesn't matter.

Americans aren't taught to write well. I had to teach myself. I assume Mr Cook is no less intelligent or capable than the rest of us, but writing is one of those things * that's "fallen through the cracks" in his life. He should do something about it.

All Mr Cook need do is tell me -- publicly or privately -- that he doesn't care about writing clearly, doesn't want to be criticized about it, and I will refrain. In the meantime, here's a book that might be of use.

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  • When I was younger, I had problems far more serious than not being to write well. Had someone pointed them out to me, and tried to help, my life might have turned out far better than it did.
Reply to
William Sommerwerck

I tried a 1 ohm in the combined ground line of a uC that decodes the IR signal in a VCR, with known IR r/c, could not observe any difference whatever function was sent.

Reply to
N_Cook

On the receiver side, the IR detector module (or optical IC) contains the AM tuned receiver and outputs the demodulated baseband digital signal. All the microcontroller will see is the coding, not the carrier. With about a 1 kHz bandwidth. It's ttl or open collector digital output.

The modules come fixed tuned for a large number of frequencies, from about

20 kHz to 100 kHz. Sharp made a lot of the modules. I think Infineon made the IC versions. You could point a modulated LED at the reciever module and find the carrier frequency by sweeping the LED drive frequency and looking at the module output.

Each message usually has all sorts of error detecting or correcting bits. Often in the form of repeating the data, inverted. Or checksums or crcs, stuff designed to prevent false operations. With about 10 to 30 bits per message, finding it by random would be too much to hope for. In the old days with dedicated chipsets, you could read the datasheet, but now the transmitter could be a cheap micro.

Different manufacturers had standard multifunction message protocols. Elektor published a number of the different message formats, (Philips and Sony, I think). But for odd gear, only the software guys who wrote the firmware would know.

Back in the first few issues, back in the late 1980's, Circuit Cellar Ink magazine had a project for a universal recording remote control. But you would need a working remote for that.

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)

Reply to
Mark Zenier

kit.

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that

Its a shame there is not an inverse of those zapper blocker remotes that send out continuous 50 KHz pulses , to stop people changing TV channel. Something that punches through all de-coding systems

Reply to
N_Cook

kit.

when

on

that

Hopefully I can get back to this hobby on Sunday , target kit I serendipituosly had one function triggered by these codes

11222322412313211 then 11521322X6112615 or also 11521322X6165 all for various apparatus in search mode of a "universal" presumably the second trigger is 11521322X61 where X is 1010 ..... ten times, 3 is 101010 etc if I had gone through the search sequence the other way then there would have been no response. I have yet to optimise the model code and then open out for the function codes before sending to a learner. Optimised as only a small section of those paired codes is probably active and the tops or tails or both are ignored

Another thing to explore is a basic satellite R/C here, which is hopeless as half of all remotes affect a channel change on it and the reverse , its r/c makes some sort of change on all sorts of equipment. So will have to explore the coding on that to see why it has a semi master key function.

Reply to
N_Cook

An extremely bright IR LED, transmitting noise over the range of frequencies used by IR receivers, would probably jam them.

Reply to
William Sommerwerck

(I guess I'm coming in on the middle of something. Huh?)

So, you're feeding some sort of code into a programmable universal remote?

Have you wired up a phototransistor, stuck it up the the LED (in the remote you want to figure out) and and fed it into a scope to look at the envelope of the control message? That would show you the format with preambles and what sort of bit by bit transmission a particular family of remotes would be using.

Mark Zenier snipped-for-privacy@eskimo.com Googleproofaddress(account:mzenier provider:eskimo domain:com)

Reply to
Mark Zenier

kit.

when

on

that

There is one design aspect in out favour. To have many buttons/functions on a zapper and not destroy ease/speed of use, the designer cannot add repeats/checks & long code/decode sequences willy-nilly, as no one will put up with a button-press response time of seconds for consumer use

Another thing I may get around to trying with this "universal"

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is it uses a simple 6MHz ceramic resonator. Replace with sig gen and vary the timings in search mose. I've done this before with another remote. I have another one-time target machine a PVR that I could not crack the coding of but managed to get a replacement zapper for. If I can find a way of cracking that one withoutout recourse to hindsight knowledge from reading the bought one, I may (unlikely I know) be getting nearer a true universal system

Reply to
N_Cook

I DSO'd 2 zappers The cheap and nasty Ross sat TV one that is easily corrupted by others and easily corrupts other kit for power button

91111111311414111 for 1 button 91111111136121111 so looks as though a lot of variability over the length (7x1 and 8x1 after the 9) is something to do with non-uniqueness

The JVC PVR zapper that I could not crack via 3 or 4 "universal" is , oddly, much simpler DVD power button

1111212125 1 button 111121253 6 button 1111213133

so seems to be just 111121 then permutations summing to 10 ,for the DVD side anyway

Reply to
N_Cook

I believe all remote controls use a "brand prefix" sequence that identifies them.

Reply to
William Sommerwerck

This zapper Ross DVB-S 5010 (rebadged Fortec ?) is probably a good start for a hacking exerciser. Pointing that 6in1 "universal" in search mode at the Rx , just for on/off and channel change on the front display shows a response to at least 33 different codes assigned for different types of equipment. The inverse is true but not so easy to put a figure to it. Now to find a couple of other equally malign and useless corrupting makes and models of zapper. any ideas for suitable googling phrases?

Reply to
N_Cook

identifies

Not my experience. These are for JVC kit on/off codes, I just DSO'd TVs

1171124 111114112211 2113 1D81D1 (D is double width mark) 8421325221111

DVDs

111121172 12432112234212111 13D4D5D12

VCR

1325 1152125 11424

Cable

27(40uS space)111114 1DD41D1

CD

1131272 Audio 114211124 11422214 11411124
Reply to
N_Cook

Its worth trying other "universals" as they are not all the same , another URC and 8 more JVC codes and 2 of a type of coding I've not seen before 1uS single pulses and varied spacing.

To see why this ROSS R/C is so useless for intended purpose but may be helpful in helping (perhaps shining ,gated ?, with a URC in search mode) exercising "dead" kit, I DSO'd all the keys So ident code of 91111111 then power 311414111 mute 324122111

1 / 136121111 2/ 121154111 3/ 111119111 4/ 121631111 5/ 131513111 6/ 112163111 7/ 145112111 8/ 122522111 9/ 111272111 RCL 212432111 0/ 234212111 TV/rad 361211111 FAV 721111121 up 119111111 left 211541111 ok 111911111 right 221423111 menu 911111111 down 272111111 exit 113612111 zoom 111451121 info 414113111 audio 112721111 up up 111191111 pause 541112111 M-P 211324121 down down 115411121

other than sums to 17 (or else I probably made a mistake ) , 9 "blocks" and ends with a 1, seems almost a random assignment

Reply to
N_Cook

On Jun 2, 2:49=A0am, "N_Cook" wrote: > Like breaking a combination lock you need a "tell " to work on. > Assuming a piece of kit, impossible to get a remote control for and > "universal " remotes do not register any change to the otherwise dead kit. > If you broke into a ground or supply line to the microcontroller and > monitored the supply current , would there be staged changes of current when > exercised by various , but vast majority wrong, IR signals? > ie simple swept 30 to 50 KHz oscillator source would you pick up on say > 38KHz as the basic required =A0"carrier" frequency =A0? > Varying mark/space of gated pulses at that "carrier" f, would you pick up on > the correct mark/space > =A0? > Then would there be a recognisable respone to various random "nibbles" that > are parts of the required coding ?

Years back I wanted to use a Sony remote (had extras) to control something completely different. I bought a 38KHz IR receiver and sat down with a scope and watched what happened and quickly found there is a method to the madness. Different width pulses, repeated inverted patterns, preambles. It wasn't too big a deal to write assembly code to receive and decode a stream. Later with an early HDTV (before integrated tuners) and set top box I did the same again and this time received, transcoded and transmitted the same command to the other boxes. BTW both Sony and Samsung (10 years + old) used 32 bits 8 start, 8 'unit ID' and 16 data bits sent as an 8 bit block followed by the same pattern inverted. I haven't looked at anything recent.

It's really nothing more than an optical modem but everybody has different protocols. They don't WANT to make it easy .

The problem is the large variety of codes and carrier frequencies available. There isn't enough room to to store all the variants in a low power system. I believe the Logitech Harmony is programmed via the PC so only needs a small amount of memory. I know they're expensive - that's why I don't have one but many folks swear by them (and a few swear at them).

G=B2

Reply to
stratus46

Years back I wanted to use a Sony remote (had extras) to control something completely different. I bought a 38KHz IR receiver and sat down with a scope and watched what happened and quickly found there is a method to the madness. Different width pulses, repeated inverted patterns, preambles. It wasn't too big a deal to write assembly code to receive and decode a stream. Later with an early HDTV (before integrated tuners) and set top box I did the same again and this time received, transcoded and transmitted the same command to the other boxes. BTW both Sony and Samsung (10 years + old) used 32 bits 8 start, 8 'unit ID' and 16 data bits sent as an 8 bit block followed by the same pattern inverted. I haven't looked at anything recent.

It's really nothing more than an optical modem but everybody has different protocols. They don't WANT to make it easy .

The problem is the large variety of codes and carrier frequencies available. There isn't enough room to to store all the variants in a low power system. I believe the Logitech Harmony is programmed via the PC so only needs a small amount of memory. I know they're expensive - that's why I don't have one but many folks swear by them (and a few swear at them).

+++++++

The Logitech is only a URC with extra bells and whistles. It has the same failing of all the others. If the maker does not have the code to laydown in its library placed in ROM or via PC , and none of the other URCs have this code to be copied across from. Then its as non-universal as the other "universals", just costs more.

The only thing in out favour is the requirement for customer satisfaction to have a speedy response to a button pusk. And also the limited number of combinations possible if there are other constraints. See my listing on the 10 th in this thread There is very limited number of vatiants if you include a 111111111 subcode because of the 9 blocks limit in this structure. A few more for 8x1 etc

That PVR I mentioned , where I obtained an original secondhand zapper. There is a piezo-tick when the clock changes digit , or any othe rfunction like choosing a letter for titling of DVD tracks etc. Shining that bad RoSS zapper (clamped down FAV function which with hindsight contained a large subsection of the PVR code) and the "6in1" "universal " some codes elicited a few of thses clicks , unkown function if anything. Reading out blink code faxhion from the "6in1" one for something Alba and one for something Philips They both had the same use of double width pulses in the code. But now having the genuine code for that PVR if must have been interpreting a double width pulses as 11 and part of the ROSS

Reply to
N_Cook

Years back I wanted to use a Sony remote (had extras) to control something completely different. I bought a 38KHz IR receiver and sat down with a scope and watched what happened and quickly found there is a method to the madness. Different width pulses, repeated inverted patterns, preambles. It wasn't too big a deal to write assembly code to receive and decode a stream. Later with an early HDTV (before integrated tuners) and set top box I did the same again and this time received, transcoded and transmitted the same command to the other boxes. BTW both Sony and Samsung (10 years + old) used 32 bits 8 start, 8 'unit ID' and 16 data bits sent as an 8 bit block followed by the same pattern inverted. I haven't looked at anything recent.

It's really nothing more than an optical modem but everybody has different protocols. They don't WANT to make it easy .

The problem is the large variety of codes and carrier frequencies available. There isn't enough room to to store all the variants in a low power system. I believe the Logitech Harmony is programmed via the PC so only needs a small amount of memory. I know they're expensive - that's why I don't have one but many folks swear by them (and a few swear at them).

+++++

When VCRs first came and no r/c option I used an old TV remote and made up a decoder and 4 programme timer from CMOS and relays to the VCR switches to make it remotely channel changeable and more than 1 , as it stood, timed record

Reply to
N_Cook

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