I have a remote which I cannot change the code running on 38kHZ

However on the receiver I could change the code - but it works with 36kHZ

How can I transform a 38 kHZ signal into a 36kHZ?

Is there a possibility to build a little electronics device which receives the 38kHZ signal and translates it into a specific 36kHZ signal?

I know its not an easy problem - but hopefully there is an expert who can help

Thanks alot

I would need more specifics on the remote and the receiver to give you better advice even if I believed what you said.

But initially, I don't believe it. IR receivers aren't that picky. An IR receiver designed for 36kHz will work fine with a 38kHz signal.

With more specifics, maybe I can diagnose what aspect of it actually is causing the difficulty.

Please let me know what might help to diagnose the problem. So far Lonak has not changed their reiceiver code since they say that i wont work with 38kHZ remote.

For us its very important that the remote works.

What can/should I try to do?

Thanks for the motivation!

What you want to do probably is not practical.

There are several differences between those two IR signals. The frequency difference, 36Khz vs. 38kHz is not important. Other differences are important.

If Lonak uses firmware inside a microprocessor to decode IR signals, then making it understand the Grundig protocol would be a difficult project for them. I'm sure they would not be willing to do that for you for a reasonable price.

If Lonak uses a third party decoder chip for IR, it would be even harder.

It is certainly possible to build a small electronic device that would receive one type of IR signal and send another type. It could even receive at 38KHz and send at 36KHz, but that isn't a significant aspect of its function. But it probably isn't a practical project. You would need to find the exact structure of the Grundig signals and the exact structure of the Lonak signals and then write microprocessor firmware to recognise one and send the other.

Why is it important to use the Grundig remote rather than get a programmable universal remote that could send both signals?


I guess that is now the part I don't believe. Depending on what you mean by "code".

If you can change the firmware that understands the way data is encoded in an IR signal, that is all you need. The frequency difference in the IR detector component doesn't matter.

But if you can only change the "address" that the device recognizes within one encoding system, that won't help because the whole encoding system is different.

I am not an expert with IR by any means - but similar to my Pronto I thought all I need is to change the HEX code in the receiver of the Linok system to the one that sends. ... because on the Pronto I normally just put the right Hex code - however I have not yet tested the pronto with Linak....

Is that too simple?

The alternative is to use a good looking learning remote that can learn and is not too expensive as a "give away" but at the same time good looking enough for our products

Since you have a Pronto, you can learn a signal from each of the Grundig and the Linak and post the Pronto Hex, so I can see exactly what protocols you are talking about and I can give more specific answers.


No. Only devices based on LIRC (usually meaning there is a whole Linux computer inside) recognise IR signals as generically as Pronto Hex. It is easy for a microprocessor to send an IR signal based on Pronto Hex (though only expensive remotes do so). It would be much harder to recognise an IR signal based on Pronto Hex.


Especially since you plan to do more than one and include them with a product, using learning for that is a bad idea. Too much work to do the learning, too hard to be sure the learning was done well each time, and too much chance the end user could mess it up.

The best idea is JP1 remotes and a JP1 cable. You would only need one cable for one time programming of the remotes. The customer would need just the remote, not the cable.

There are JP1 learning remotes, but whether the JP1 remote is learning shouldn't matter to you. You can use your Pronto to learn the signals once to get the info to program JP1 remotes.

To get a cable and a few remotes, order from Rob at:
[Link: hifi-remote.com]
He does ship to Europe at a reasonable rate.
For a larger number of remotes, Rob may be willing to give you appropriate contacts, or that might not be too hard to find yourself.
The JP1 compatible remotes normally sold in Europe cost more than shipping comperable USA models from the USA.

I'm not sure which JP1 model you might consider good looking enough for your purpose. From Rob's web site, you can find pictures of all the models.

There are other brands of remote that can be programmed by a cable connection to a PC that are less expensive than a Pronto. But those are generally still more expensive than JP1 remotes and harder to program.

JP1 remotes are barely more expensive (not counting the cable) than cheap learning remotes. And you only need to buy the cable once. Programming by cable will be much better than learning.

When reading Rob's list of models the "mod" means he modifies that model to make it usable with JP1. If you bought the same model elsewhere it wouldn't work. JP1 models he lists without the "mod" will work with the JP1 cable regardless of where you buy them. The JP1.2 models will also work with a cable regardless of where you buy them, but it is a different cable. The 8820 is the model easiest to find at a good price from sources other than Rob (if you're trying to control your cost that tightly).

Once you have the data captured (via Pronto) from the two remotes, you might want to ask Rob about programming JP1 or JP1.2 remotes for you, so you wouldn't need to get a cable nor learn that software.

About the JP1 - this is really a good way to make ones "own" remotes - however the problem I see is that the user will have a totally different layout than ours which is too complicated. However, its certainly much better than using a learning remote as you pointed out!

I just would like to try everything to avoid this

Many thanks!

I'm sure that is not the case.

Seeing the signals would let me be more specific about a JP1 solution. It would let me be more specific about a translator solution. It might make it easier to explain WHY changing the Linak system would be hard. But it would not give the answer you want (an easy way to change the Linak).


What is "inexpensive" and how many would you be making?

The basic parts are simple and inexpensive: A microprocessor, an IR detector and an IR LED. But you need to supply power (probably 5v DC, maybe 3v depending on what micro you select). You need to package it. You need firmware to recognise one type of IR signal and send another.

I have seen forum posts by at least one person who has already done that as a hobby project. By I forget which thread and I'm not sure what keywords to search for.

Since the "translator" would have to be build into our sideboard anyway there is no problem for a power supply.

As for the price 5-10$ / unit is OK. As for the number, I expect that we will need around 30-50/year

Can that really be done?

Under 10$ in electronic components is easy. But I don't know what packaging parts you might need. Would it be added on to the electronic design of your main product, or physically seperate?

You would find a much better selection of microprocessors in surface mount than dip. But surface mount would only be practical if you are already doing a surface mount board and you can modify its layout to include the extra chip.

The IR detector is a three lead discrete part, that you can mount on the circuit board if that puts it line of sight to the remote, or you can run those three wires to wherever you want to mount that.

A very low power IR emitter is a two lead discrete part. I assume that would not be correct line of sight and/or not close enough if mounted on the main pc board, so you would run two wires to mount that where desired. A higher power IR emitter (to let you put it further from the Linak's IR detector) would need an extra component (probably just a transistor) to amplify the signal from the micro. A prepackaged IR emitters (with the long wire and a connector to plug into the circuit board) would be simpler, but would push your parts cost over $10.

An alternate physical design would be a dedicated mini pc board to hold just the translator and mount all that directly at the Linak's IR detector, and wire just power to it from the main board. But I don't see that design being under $10.

Depending on the physical design of the Linak, and other factors, maybe it is better to cut the IR detector off of the Linak board and wire the output from the micro (that would drive an IR emitter) directly in place of the Linak's IR detector. You would need the specs on the component they use as an IR detector.

If you're real lucky with physical design factors in the Linak, you might skip your own IR detector as well: Cut just the output signal from the Linak's IR detector. Wire that as the input to your micro, then wire the output from your micro to where the output of the Linak's IR detector went.

The big problem is design cost. 50/year is not enough to justify normal design costs for such a device. Maybe some existing hobby project posted online has firmware close enough to what you need to cut most of what would otherwise be a big programming task. But more likely not.

BTW, what signals from the Grundig remote would you want to use to drive the Linak? I assume every signal from that remote has an existing and required meaning for the TV. So all Linak functions would need to operate in parallel with Grundig TV functions.

Does that remote have seperate On and Off buttons, or does it have an On/Off toggle? With an On/Off toggle it is possible the two devices would get out of sync and it would be difficult and confusing for the customer to get them back in sync.

So it seems that there is no feasible way to use the Grundig remote to control Linak.....

Thats not good news since we already have finished our prototype of the sideboard with the Linak lift technique for the LCDs. The user would then need Linaks remote to initiate the up or down lift and the Grundig to control the LCD. Thats not good at all .

What is the complicated part to creater? I mean the Linak also can be initiated by pressing an up or down button of a manual device which is connected with a cable instead of a remote. I guess these buttons "just" closes a simple curcuit of some kind to give the impulse for up and down.

Would it be easier to "just" build a device that receives the Grundig code - and then reacts by closing the Linak circuit of its manual control unit?

This receiver just has to recognize the correct signal from Grundig - it does not have to send any IR by itself to the Linak system.

Is that feasible?

Is it really that complicated to build a receiver for a certain IR code?

I don't know which Grundig signals you have. For some Grundig signals there was a Motorola chip that decodes the signal in a way that probably could be wired to the Linak's manual control. I don't know whether that chip is still made. Almost everyone decodes IR with microprocessors, not with dedicated IR decode chips.

You didn't answer the question about which TV function you would use to control the Linak. Every TV function means something to the TV, so whatever buttons you choose for raising/lowering the TV would also do something else and vice versa.

We are using a Grundig TP 170C remote and have planned to use the clock button or a combination of AUX or PR and another button. Using a combination should be OK since there will be no conflict for the TV at all. And if all buttons work with AUX or PR then there are anyway many possibilities that will not conflict neither with the TV nor with another potential device.


Regarding the Chip and other technical details...
I can find out all the required details inside the TV that is required. However, I cant build such a device and I am not sure if something like this can be done at all.

Just in principle, what would have to be done to receive a specific sigal and recognize it as beeing the right one? Are there a generic chip which recognize any combination and one could get the signal from specific pins or is there always a software development work which of course we can not pay for anyway?

The only info I have on Grundig remotes is from:
[Link: remotecentral.com]

Since none of those mention TP 170C, that doesn't tell me anything. Pronto Hex from some of its signals would tell me something.


Doesn't the TV respond to that same signal?


I don't know what AUX an PR are on that remote.


I really don't understand what combination might mean in this context. It sounds like you mean press two buttons at the same time. I doubt that does anything that you could use for this purpose.


Maybe you mean the Grundig remote is semi-universal, has mode keys to make it support some devices other than the TV. If true, and if the end user won't get confused by the mode keys, that opens up a lot of possibilities. Do you have documentation on what other devices the remote supports. Maybe one of those is the same IR protocol the Linak uses and all you would need to change is that address I mentioned above, which would be easy for Linak to change for you. (But that is all extending pretty far off a guess at what you might mean about AUX and PR).


For some IR protocols, there are (or were) specific chips that recognize that specific protocol. You wire pins on the chip to encode the address it should respond to, and then other pins give the results. There are Philips chips for the various IR protocols that are used mainly in Europe (wild guess, Linak now uses one of those protocols, even if they don't use one of those chips). There are NEC chips for the worldwide most common protocol. There is (or maybe just was) a Motorola chip for the Protocol used in many (certainly not all) Grundig TV's.

Anything more generic requires programming a microprocessor.

The Grundig remote only supports their own devices. In that sense its semi universal - one changes the mode by pressing a preceeding button like DVD or PR (=personal recorder)

I have now learnt the code of a P key and the code of P preceeded by PR - whatever that will be used for in the future....

P
0000 0073 0000 0009 0013 005F 0013 0026 0026 0026 0026 0026 0013 0013 0013 0013 0013 0013 0013 0013 0013 107A
DR + P
0000 0072 0000 0009 0013 0060 0013 0026 0026 0026 0026 0026 0013 0013 0013 0013 0013 0013 0013 0013 0013 10A4

Does this help in any way? I will check which chip they use - i will take a picture of it next week.

Actually I cannot imagine that they use something exotic - so I hope there is a way to build the transforming device after all.....?