Introducing the [Disassembly] series and the BTI-029 Bluetooth Transmitter and Receiver

So this is a new theme. I take far too many things apart. I usually put them back together afterwards, but the justifications I use in each case are usually as flimsy as cling-wrap. So why not blog about it too.  After all, might someone else want to see inside a BTI-029 Bluetooth Transmitter and Receiver so much that they google BTI-029 disassembly?

Time will tell.

What is it?

The BTI-029 connects an 3.5mm audio jack or S/PDIF device to Bluetooth. What makes this device relatively unique is that it can be set to operate in either direction, and it has S/PDIF connectors for the wired side. 

Why do you have it?

For some bloody reason, Samsung decided that the only audio-out my TV should have (aside from the speakers ofc) is a Fiber Optic S/PDIF aka Toslink port. Ergo, the BTI-029 is about the only way I can figure to connect a pair of headphones to the damn telly.

Why did it deserve to die? Why are you taking it apart?

I dream of building an audio mixer to mix multiple sources (eg phone, pc, other pc) to a single set of headphones. Bluetooth would make it pretty cool. But most commonly available Bluetooth modules are receive-only. Both common transmission-capable modules (the BC127 and the RN52SRC) have been discontinued. By dismantling the BTI-029 I can find out what modules other devices are using for transmission. The reckoning is that this device should contain a standard but transmission-capable Bluetooth audio module and little else.

How to disassemble?

The rubber underside is attached using double sided tape. Using a guitar pick to start the peel, the two case screws only showed their heads after removing the whole thing. After the screws are removed, the guitar pick is used to snap out the black top panel of the case.

What did you find?

I found what I had expected  - a transmission-capable Bluetooth audio module and little else. Oh, and a battery. I forgot that. The BTI-029 can operate for hours without external power.

I was also surprised to find the anti-reverse engineering team hadn't obliterated the top-side label of the Bluetooth SoC on the Bluetooth module. They'd merely superglued the QC label to the top-side of the chip.

Removing the QC label was simply taking the guitar pick and chipping off sub-millimetre chunks at a time, hoping the sideways sheer force was not kicking it too hard in the ball grid array. 

And the answer to my question is finally there - the module is Qualcomm CSR8670 SoC based. So it doesn't tell me the module manufacturer. The SoC transmit functionality will be entirely up to the module vendor. But at least it gives me something new to google...

Any final impressions?

I'm still confused about the battery. Sure, the CSR8670 SoC offers LiIon charger functionality. But do you actually have to use it just because it's there? Actually... come to think of it, I'd be comfortable in a world where all devices have serial ports fitted.

Oh, and yes, it did go all back together afterwards. I can still watch telly with headphones.