Help with Wireless Microphone sync protocol

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alwayslearning
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Joined: Tue Feb 05, 2019 12:38 am

Help with Wireless Microphone sync protocol

Post by alwayslearning » Tue Feb 05, 2019 1:13 am

Hi friends!

First time posting and also a new user of AnalysisIR!

I'm hoping for some help deciphering the sync protocol for the Sennheiser EW100G3 Wireless Microphone system.
https://en-us.sennheiser.com/clip-on-la ... -ew-122-g3

One feature of this model is the ability send the receivers radio frequency to the wireless mic pack(transmitter) via an infrared sync routine. Simply press "Sync" on the receiver, align the IR windows of the pack and receiver, and the receiver sends the frequency to the pack.

It seems this is a 2-way conversation. The receiver is sending out a stream of data, possible "looking" for a compatible transmitter, once found and verified, the additional packets of data are sent along. (this is just my theory).

What I'd like to do is decipher what part of the code holds the actual frequency number (525.900Mhz, etc..), store that, and then load that into a generic learning remote. Use this remote to load the frequencies into a pack without having to have the receiver close at hand.

I've been able to use AnalysisIR to capture both the receiver codes as well as the pack code. (files attached)
Yet, I have no idea how to implement this.

Using a Arduino Uno with a VS1838B

Thanks for any guidance!
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AnalysIR
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Re: Help with Wireless Microphone sync protocol

Post by AnalysIR » Tue Feb 05, 2019 9:51 pm

I had a look at those mics online...

It may be that the IR they are using is IRDA not CIR (Consuer Ir remote control). these are different. They dont say much about the type ofIR they are using.

So the first thing to do is to post a photo of the IR sender /recever ports on both the mic & recevier.

(If there is 2 small bumps/lenses visible, then it is more likely IRDA)

The other possibility is that the carrier frequency is different from your receiver. Please post the receiver module you are using.(+link).

Finally, if you look at the IR ports thru your phone camera check to see if you can see a ligh flashing as teh unitis are communicating.

Post back how you get on.

PS: The signals you posted are all just noise and of little practical use.

alwayslearning
Posts: 12
Joined: Tue Feb 05, 2019 12:38 am

Re: Help with Wireless Microphone sync protocol

Post by alwayslearning » Tue Feb 05, 2019 10:11 pm

Thank you!

I'm away fron the units now yet will try to post a few photos later.
I will say the IR ports are just smooth red plastic (no small bumps visible).

The IR signals ARE visible through my phone.

Regarding the scans, these were my first attempt using AlalysisIR.
I did notice the receiver was registering noise before and after engaging the SYNC function.
I assumed the signal would we clear over the noise.
I'll try again. Maybe using the recommend TSOP34438 .

More soon...

Thanks!


alwayslearning
Posts: 12
Joined: Tue Feb 05, 2019 12:38 am

Re: Help with Wireless Microphone sync protocol

Post by alwayslearning » Wed Feb 06, 2019 9:55 pm

Hi again,

I was able to snap a few photos today of the IR windows and also grab hopefully a better set of data.
I'm using a Arduino UNO with a VS1838B. (which I've noticed, picks up quite a bit of noise when the sun is out. Is it recommed to decouple the 5V VCC supply coming from the UNO?)

Would purchasing one of the receiver modules help with this noise?

After closer inspection, I can't capture the IR flashes with my phone. Not sure if this is "operator error" or not the correct format.

Photos and files attached.

Thanks friends!
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AnalysIR
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Re: Help with Wireless Microphone sync protocol

Post by AnalysIR » Wed Feb 06, 2019 11:51 pm

No photos uploaded?

That VS1838B IR receiver is total rubbish! There is a good article available on our blog.

Keeping receivers away from sunshine is always a good idea. However,I wouldn't bother with that particular one.

Getting a better receiver Module would help. TSOP34438 or other TSOPxxx38.

Alternatively, pick up one of the modules or receiver kits in our shop.

I noticed your captures also report a ~34kHz carrier. I preusume this is just spurious from that receiver.

If not, then consider our LearnIR device which has the widest coverage (20kHz to 60kHz).

alwayslearning
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Joined: Tue Feb 05, 2019 12:38 am

Re: Help with Wireless Microphone sync protocol

Post by alwayslearning » Thu Feb 07, 2019 12:50 am

Oops. Photos attached.

Thanks!
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AnalysIR
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Re: Help with Wireless Microphone sync protocol

Post by AnalysIR » Thu Feb 07, 2019 1:14 am

tnx....as you suspected not much help :)

I also forgot to mention that the 'receiver send data' signals you posted could potentially be 1 byte @ 4800 baud serial or 2 bytes @9600.

However it is generally a bad idea to operate at those speeds (except IRDA)

We will need better captures to proceed.

alwayslearning
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Joined: Tue Feb 05, 2019 12:38 am

Re: Help with Wireless Microphone sync protocol

Post by alwayslearning » Thu Feb 07, 2019 1:51 am

I understand. I ordered the LearnIR device today.

So I can better understand AnalysisIR, what are the indications that my most recent captures are of poor quality?

Ona side note, I have family from Clonakilty. I was visiting that town and others in the south last summer -- beautiful country!

Thanks for the help!

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AnalysIR
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Re: Help with Wireless Microphone sync protocol

Post by AnalysIR » Thu Feb 07, 2019 8:42 pm

So I can better understand AnalysisIR, what are the indications that my most recent captures are of poor quality?
very little signal from the receiver & noisy/sporadic/no-regular patterns on the mic signals.
Ona side note, I have family from Clonakilty. I was visiting that town and others in the south last summer -- beautiful country!
I have some distant relations in that 'neck-of-the-woods'...lots of similalarly nice places to see all around Ireland....although usually a few degrees warmer towards the south west, because of the 'Gulf Stream' :)

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