I'm trying to identify the IC inside the remote control for my DuneHD media player.

It's a 20-pin surface-mount package with no identifying marks.

I've discovered the following so far:

It uses the NEC code scheme;
Pin 6 is the output to the IR LED;
Pin 3 is the output to the "sending signal" LED;
Pins 17 & 18 connector to a 3.64MHz ceramic resonator.

Attached are some photos of the item in question.

If anyone could give me some pointers as to what IC it might be, it would be very helpful

 

It is most probably a custon programmed chip and so it will be unobtainable.
Why do you need to know whai it is?

 

Maybe PIC16 of some sort (e.g. PIC16F88)

Maybe not - as pin 6 to LED does not fit the profile.

Don't know how knowing chip helps, since it will not possible to copy it.

 

OK, why do I want to know...it's a bit of a story...

I purchased a lovely new TV, and it is great. However, it's remote control also uses NEC code and conflicts with the DuneHD. Really inconveniently. Like pressing "volume down" on the TV remote makes the DuneHD go into standby. Annoying!

So, I thought, there are three things that define an IR remote interface: IR wavelength, carrier frequency and coding scheme. If I change one of those, it shouldn't conflict anymore.

In terms of ease, IR wavelength seemed the best bet. Just swap out the transmitter and receiver LEDs for ones on a different wavelength and job done. But no, there don't seem to be any readily available far enough outside the consumer IR wavelength (around 950nm) that the TV receiver wouldn't pick it up. So scratch that.

The next-easiest thing to do is then change the carrier frequency. This seems do-able, so I went looking for an alternative chip that I could put in the remote control. I found several (such as those by Renasas) but none fitted the profile- hence my question.

I'd be surprised if it were a general-purpose uC like a PIC, but I guess it's possible. If I could find a uC to fit the profile I guess I could just read all the codes from the existing remote and program the new chip to send the same but at a different carrier frequency.

Oh, and the last alternative, changing the coding scheme...not happening!

Other than "get another TV" or "get another media player", I'm open to suggestions.

 

I think this is not a real easy thing to fix. If you can locate an LED transmitter and receiver that run on a different wavelength you may be able to change both ends.
But the receivers are usually a photo receptor, amplifier, tuned filter and pules output, but not the command decoder. They deliver a pulse train to control micro and it does the decoding. So you will need to produce the same pulse train as the old one. Just changing the transmitter will not work.
You may be able to modify an IR repeater to receive, for example, green light, add a green LED to the remote, and place the repeater IR transmitter against the TV IR receiver in a way that blocks other IR getting into it. Then the same codes from the remote still get to the TV.
Quite a problem. I will be interested to see how you go.

 

In terms of receivers the DuneHD has something like a Vishay TSOP module, which, as you say, is more than just a receiving LED.

Luckily, the TSOP range comes in several different carrier frequency variants so I think the receiver end should be relatively straightforward (he said...famous last words!).

I did consider using a modified repeater, but I don't really want to add more hardware and make the system a pain to use.

I suppose I could make a wiring adapter to go from the pads on the remote control PCB to any sort of uC I like, but that feels messy and potentially unreliable. Might be the only way though.

 

Yes, PIC was a dumb idea now I think about it

The first Dune HD device I googled has an external IR connection. Does yours? If so... is it for an external sensor or for external IR transmitter?

Maybe you could build a gadget that receives IR from a completely different IR remote (eg Sony) and converts it to NEC to suit DuneHD

I did something similar when I lost original remote control. The result was horrible, clunky and irritating, but it got me out of a hole. I was so happy when I re-discovered the original remote.

Probably impractical for you, since would would need to understand three sets of remote codes, 2 protocols and would need to understand how to build and program whichever micro-controller you choose for your gadget. Finding a suitable other remote with enough buttons might be a nightmare. You would need to own oscilloscope or logic analyser and have basic electronics skills

Maybe you could convert Remote to wired (nasty)

Maybe you could somehow split the IR paths with clever blinkering. Possibly using IR repeater (RF) to send one signal, and line of sight for the other. Another nightmare to implement I would imagine.

I cannot see any sensible solution, and only mention the silly options above in case it triggers some other idea.

Wonder if any TV forums might have discussions on possible solutions. I know that my SkyQ IR remote causes my Samsung blu-ray player to open/close the tray whenever I change channel. Solution for was to swap Samsung player for older Sony I already had. Solution on Sky forum was to upgrade Samsung firmware - except it turned out that no such update existed.

Will be interested in your progress...

If you are in UK, I would be willing to post the IR receiver/converter/sender that I no longer use, but this would depend upon you knowing every detail of the NEC codes that you use before I can program it for your needs.

Provide links to your TV and DuneHD manuals and I might come up with some even dumber ideas for you...

 

Can you identify the receiver in the DuneHD specifically. Pinouts are fairly standard, but it would be good to know -- particularly for the operation voltages.

As you and others have suggested, I think your only chance, a slim one at that, is to change the emitter carrier frequency and swap the receiver to match. Changing the emitter may be as simple as substituting the 3.64 MHz resonator with one at a higher or lower frequency. For example, if the carrier is 38 KHz, changing to a 5.46 MHz resonator might give a 57 KHz carrier which is close enough to the common 56 KHz receiver that it may work. While receivers do filter the incoming IR signal, I am not sure that the differences between frequencies are enough to prevent cross talk at close range.

Do you have a simple IR detector and oscilloscope that you can use to determine the carrier. You may even be ale to probe around on the remote with an oscilloscope and find out (or it may be in a maintenance manual).

Other than that, you may be stuck moving the DuneHD to another location and/or covering the receiver's window.

 

I would imagine that changing the resonator frequency would mess up the NEC timings. Not tried it, so I could be wrong...

... but then again, maybe a converter box could read mangled NEC and change it back to valid NEC to go to the DuneHD IR input connector (assuming that it is for input)

Wonder what other side effects resonator swap might cause - can't think of any off hand.

Wonder how many modifications the remote control can stand before breaking. I would want a couple of spare handsets available before risking trashing my only one

 

I did think about just changing the oscillator, but it will almost certainly mash up the whole NEC code along with changing the carrier frequency.

My Dunes do not have any external IR connectors, but do have an I2C jack on the rear panel. So far I've not been able to find out what I can do with it (if anything).

The TV: https://d3537i9v051wn8.cloudfront.net/uploads/2018/04/A6250-User-Manual.pdf
Dune manual: http://dune-hd.com/eng/support/online_manual/getting_started

 

I did discover something on the Dune website...some information on how to access the player via Ethernet.

So a whacky idea occurred to me...how tiny/low power could a wifi enabled processor be? Small enough to fit in a remote control case perhaps??

 

Time I admitted to being out of ideas.....

I see that Dune has the option for IP control, but that looks complicated.

I see that the TV has a service port, but I would not want to mess with that.

Can't think of any effective solution. Maybe someone else will.

EDIT: - just spotted this device, which controls via USB: https://www.scan.co.uk/products/dun...h-touchpad-mouse-and-hotkeys-designed-for-the

.. and phone apps ... http://dune-hd.com/eng/support/applications_and_drivers/rc_applications

 

An ESP8266 or ESP32 may work, but also, look at an old Android phone. If you connect the phone to your home WiFi, there are apps you can use to make it a remote.

 

Thanks guys, I think I'm going to go with using the Android app for now. I've got an old phone in the drawer which I can use as a dedicated remote for the Dune.

Thanks for all the suggestions...I wonder how common the problem is? Strange that there isn't a product on the market to deal with it.