455khz ir old B&o stuff

Manufacturer: Bang Olufsen
Model: the old stuff

So I tried controlling my old TV and stereo but since it’s a 455khz ir signal nothing responding to the community codes in the R2.
BUT if I hook up a 455khz ir diod to the ir output of the R2, would that work?!

I don’t see a reply from anyone more knowledgeable than me about IR codes, but I’m guessing not. Where are you getting the codes for the B&O stuff? I believe the carrier freq. is specified somewhere in the hex codes, but 455 is a long way off from the 38 used by the Pronto stuff. What do you mean by “community codes”? The diodes in the dock may or may not work at 455, but that may not be your only issue.

In pronto raw, the carrier frequency is actually provided in the second value, but not in a direct way.

F = round(1000000/(N * 0.241246))
where F is the frequency and N is the number from the pronto code.
You can also reverse the equation to get the N:
1000000/(F * 0.241246)

It’s not possible to get exactly 455 kHz, but for about 460 kHz (close enough) the N is equal to 9.
So the pronto codes would then start with:
0000 0009 ....

It’s not a matter of the diodes. You should not need any special diodes for that. It’s a matter of whether the ESP32 (microprocessor in the dock) and the firmware is able to modulate the signal that fast. I think that may be at the very limit of the library used for generating IR signal, but it may generate something closer to 500 kHz.
It’s because it calculates the burst cycle time using this equation:
T = round(1000000 / F)
where F is the frequency and T is the time in micro seconds per cycle. With F = 460000, T is equal to 2. If you turn this equation around, then
1000000 / 2 = 500000
so 500 kHz.

These equations work great for lower frequencies, but loose precision with higher ones.
I have no idea if the B&O equipment will be able to demodulate 500 kHz signal.

I just used the guide under “remotes → infrared”. Where these codes in the guides comes from, I don’t know. But there are lots of devices!

Not a clue if that could work, I just know old B&o stuff used 455khz ir signals. If I try to make my own ir collection in the remote I see the dock blink like it’s receiving signals but I can’t get it to record any.

The dock won’t be able to record 455 kHz signal for sure. I don’t know how the dock looks inside or specific parts UC used, but looking at the C++ library the dock uses for IR sending and receiving, I’m quite confident that the IR receiver used in the dock is the demodulating one.
Demodulating IR receivers work only with specific ranges of carrier frequency and won’t even react to anything outside of its range. The receiver is probably for 38 kHz +/- few kHz. It strips the carrier frequency from the signal passing only pure, low frequency signal with the data to MCU.

yawor is the kind of forum user who knows more about IR than I do I was referring to If he’s right about the dock not being able to record 455khz signals, and there are no other issues, you could try loading codes from other sources, like the manufacturer or Global Cache. Another possible problem pointed out, though, is worst case the carrier frequency the dock would generate could be as far away as 500khz which may not work with your stuff. You don’t specify exactly what B&O stuff you’re trying to control, but I would check Global Cache. Follow the threads here on loading their codes, it’s a lot easier than it looks. You just need to change a couple of items in the headings.

I don’t know much about B&O, except that I used to own one of their phono cartridges half a century ago, that I have a brother who’s a fanboy, and that they like to play in their own ecosystem, which may not play well with UC. They do/did make a lot of nice stuff for controlling their systems remotely, but they don’t make it easy to use third party stuff. But good luck. I suggest you try obtaining csv (comma separated values) data for your stuff, try loading it, and see if it works.

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