BT earpieces

It probably depends a lot on the specific model. I have done it to a cheap Chinese one from DealExtreme:

It wasn't even difficult.

If look at the link, there are even a couple of decent quality pictures from its internals.

You might have to be a bit more specific there Don.

BT Earpeices could be a number of things.

To some of us in UK they could be the British Telecom standard item for call-centre and switchboard personnel where they are on the phone for long periods of time. These are usually the Aerolite headset but there are a number of different makes and models available.

Alternatively I suppose you could be looking at the Bluetooth devices make it seem that people are talking to themselves when they are actually talking on the mobile phones.

I would expect that most of the latter ones use a cheap microscopic microphone element. If what you wish to do is connect a different microphone then I expect that should be possible. Sounds like you need some serious playtime.

Ah, sorry, some confusion, there. My bad. This is more like what I was talking about:

with the differences being:

- smaller size (?)

- microphone (i.e., duplex operation)

- not a "music player", etc.

I.e., the sort of thing you use with a BT enabled cell phone for "hands free" operation.

Ah. No, BT == BlueTooth. My bad.

Yes (good description! ;-)

I've pulled apart some small voice recorder/MP3 player devices and the microphone in those was tiny -- though I could easily hold it in my fingers, unsolder it, etc. Most of the BT earpieces I've seen seemed a fair bit smaller, though. I was wondering if there was an even greater level of component intregration that would make attempts to *modify* them essentially fruitless.

Ditto for the "earphone".

Yeah, I was hoping to avoid dismantling one until I knew if that would be *likely* to yield promising results. :-/ I guess it's time to make a sacrifice to the electron god...

Well, a package of that size wouldn't be too bad -- just like soldering SMT components.

What I am more fearful of is this package being *integrated* into an SoC-ish implementation -- making the connections inaccessible.

Probably smaller. But unless size is important, the bigger ones are probably easier to hack.

Take a look at the pictures of the internals. You'll see the microphone soldered directly to the board, pointing sideways.

This does both. You attach it to your shirt near your face. The mic is built into the unit. You can choose to connect mono or stereo earpiece, depending on wheter you want to talk on the phone or listen to music. The included earpieces sound horrible, though.

I need to put this inside an existing (small!) container so the size of the item I cited was appealing.

Ah, OK. I missed that in my first glance! Points *down* (in the photo I studied)

Do you have to press any buttons to get it to *do* something? (i.e., can you just use it as long as power is available?)

But, the *earpiece* was the problem, not the device? (i.e., if you had replaced the "earphone" -- which I intend -- then things would be better?

Hmmm... maybe just buy one and take it apart...

Thanks!

If the product is registered with the FCC, you can often see the guts on the FCC website. Occasionally the manufacturer requests confidentiality, but more than often not.

I recall an old story about BT (British Telecom) microphones, back in the days when they were known as the Post Office... I heard this 20 years ago when I worked in telecoms, and it was old even then.

For several decades these were carbon, and had very uniform characteristics. Then one day someone noticed the frequency response was out of spec for all new ones. Engineers investigated and eventually zeroed in on the carbon itself, whose characteristics had subtly altered. Inspectors ended up in Wales where a coking plant created the carbon by anaerobic heating of coal or whatever (packing it into a sealed chimney and cooking it like a closed oven for a couple of days). And yes, the carbon was definitely different somehow. But following the manufacturing process from start to finish, they were at a loss to explain where the operators were deviating from the written procedures.

Looking for correlations with events that happened around the time of the change, they discovered that it coincided with the retirement of a foreman. Further enquiries revealed he had a curious habit of "marking his territory" before each "shot", ie urinating on the pile of coal before it was sealed up. Experiment showed that this was, indeed, the X Factor which brought the carbon back into spec.

And so BT continued making carbon mikes for many more years.

If the phone is already paired and in range when the device powers up, it connects automatically. If the phone goes out of range and comes back into range, you have to press and hold the button to reconnect. To answer an incoming call, or to initiate an outgoing voice dial, you have to press the button.

For music, I can't quite remember. I have tested it, but don't use it.

Yes. I tried listening to music with a different pair of (also cheap) earphones (it's a standard 3.5mm jack), and they sounded fine.

Considering the cost, the risk is minimal. You could even get a couple of different models to see which one is most suitable.

I wanted to bury the buttons completely.

OK.

The size and button issues look like deal-breakers. :<

Thanks, anyway!

Hmm. I'll test and see if I can answer the call from the phone. I expect that should work, but I have never (consciously) tried.

Ok, I have tested. I can answer the call from the phone, but I cannot re-establish the connection after having been out of range.

While I'll admit that I expected you would need to explicitly pair the device *initially*, I guess I am surprised that you have to repeat this procedure, again, when you "simply" move out of range.

Or, am I misreading your statement: the device may remain paired but this *session* is "broken"? I.e., you can "answer" the next call but can't "reconnect" to the current?

(sorry, I don't mean to be splitting hairs -- but I

You don't have to repeat the pairing (with PIN codes etc.). But it seems the phone is not aware that the headset is in range until the headset sends some sort of notification.

I've never tried to go out of range during an ongoing call.

There is a small icon (a headphone surrounding the BT logo) on the phone that shows that a BT headset is connected. If that icon is shown when an incoming call arrives, the BT speaker beeps to indicate the incoming call, and the call can be answered from the headset with a short press of the button.

If the phone goes out of range, the headset icon disappears and does not automatically come back when the phone comes back into range. In this state, an incoming call cannot be heard or picked up from the headset. What you can do, is to press and hold the button for a couple of seconds to initiate the reconnect. That takes a few more seconds, and then you can answer the call.

I know some BT hands-free units (which is essentially the same thing) will reconnect automatically when the phone comes into range. I once was in a conversation with a person who was walking towards his car. As he got close enough, the audio was automatically transferred to the HF inside the car, and we could not hear each other until he opened the door and got into the car.

But, once the connection was made, why wouldn't it persist/resume

OK. So, the headset creates another "session" with the phone at that time.

Hmmm... so, maybe the issue is in the *headset* trying to prolong battery life? I.e., when *it* no longer senses the BT connection as "live", perhaps it powers down? And, repressing the button powers it up and sets it hunting for its paired mate?

I will have to play a bit to identify where the disconnect is happening.

Thanks!

I don't know, but I presume it is to avoid spontaneous transfer to the BT unit if it should happen to come in range. Say I am talking on the phone while walking towards my office (where my BT unit is located). Once I get a few yards outside the door, I'd lose all audio.

Yes, the phone automatically transfers to the on-board microphone and speaker. I don't have to do anything on the phone to get it working normally.

It does not look like it. The BT unit makes a specific type of beep when it is powered on (also by holding the button for a couple of seconds), but a different beep when only reconnecting a lost connection.

But, presumably, you can deliberately tell the connection to be made/broken. What I am saying is why wouldn't the device seek to maintain whatever mode of operation was in effect "prior to the (temporary) loss of signal"?

I.e., you can pair the devices. Then, decide if (any particular) connection (call) should be routed over the headset or the phone itself. Once this decision is made, it should persist until you explicitly tell it otherwise. Yours seems to behave as if "loss of carrier" is the same as "I want you to disconnect". The former is something that the user has little direct control over ("don't wander *too* far...") whereas the latter is a very deliberate action (normally) on the user's part.

But, the latter is still only done when the user "reinitiates" it, right?