3D glasses IR control protocols...

[digital_silence]

Hi all,

Not sure if this topic has been discussed before. As many of you know, there are different ways 3D TVs control their active 3D shutter glasses. The most common ones are IR (earlier models) and WiFi (later models). Obviously, those are not intercompatible.

I have an LG TV set that uses IR control channel (with only one pair of glasses) and I also have plenty of WiFi-controlled 3D glasses (also LG)

I am wondering if the 3D glasses control IR communication is in any way compatible with the IR remote control one.
My idea is to build a IR-to-WiFi translator to make all my 3D WiFi glasses usable on either of the two TV types. I can handle the Wi-Fi part, but lacking the industry knowledge of the IR part.

Anyone to comment?

Thanks,
DS

[Barf]

We had the topic in 2011.

I think the timing requirements are pretty tough.

[digital_silence]

Thanks Barf, interesting topic. I am proud to submit that I have understood 99.9% of the info from there, including the tech lingo.
I think though that the topic starter of that thread was more on the software/firmware side of things, so the restrictions of the existing JP1 hardware were the limiting factor.
Regarding the timing - since the whole shutter pattern is repetitive, we always have a luxury to introduce a delay of (Full cycle time - lag) time to be late exactly by one cycle... :-)
I guess, I just have to take an IR receiver and see what comes out of the 3D TV while watching the 3D contents. Maybe even get a learning remote and pray that the carriers match...

[Barf]

Regarding the timing - since the whole shutter pattern is repetitive, we always have a luxury to introduce a delay of (Full cycle time - lag) time to be late exactly by one cycle...

Strictly speaking, you only need to ge the "phase" right; if you are "off" by an integer multiple of the period (which is 1/frame rate, or an integer fraction thereof). But I am nor sure if that buys you very much.

I guess, I just have to take an IR receiver and see what comes out of the 3D TV while watching the 3D contents. Maybe even get a learning remote and pray that the carriers match...

Just for the fun of it, I put my favorite IR capturer in front of my Sony VLP-HW50 showing a 24p movie (makes around 42 milliseconds per frame), and with IrScrutinizer I captured this sequence

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+71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667 +71 -310 +71 -945 +71 -229 +71 -8667 +71 -148 +71 -945 +71 -390 +71 -8667

(no modulation that I could detect).
I put it into IrpTransmogrifier, which reduced the signal to

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{1,msb}<>(71u,-310u,71u,-945u,71u,-229u,71u,-8667u,71u,-148u,71u,-945u,71u,-390u,71u,^21m)25

Just spent a few minutes, without really starting to think hard...

(Command line was irptransmogrifier -a 50 analyze --timebase 1 -e --rep -s +71 -310 ...)

[Barf]

Looking at the plot

(again produced with IrScrutinizer) shows that there are, within the 21 milliseconds window (this is half of the frame time 42m) there are four pairs of two pulses. It appears to be fairly safe to guess that these pair of pulses turns the individual glasses on and off.

[Barf]

@digital_silence: any further success?

[digital_silence]

Happy New Year everyone!

@digital_silence: any further success?

Sorry for the long (digital) silence. My IR-emitting LG TV went (temporarily?) to the relative's house as their TV broke, so no further progress on this task, sorry. Might have to switch my focus to WiFi (BlueTooth) as I also have a 2.4GHz 3D glasses and matching 3D TV set (LG)... may not be that straight forward though as this is most likely a two-way comms, and most definitely so for BlueTooth or BLE.

So the increasing complexity of this task is naturally suppressing its priority... which in plain words is called laziness... :-)

Oh! And WiFi fits the profile of this forum to the much lesser xtend than IR (strictly speaking :-)