OSTC over BLE experiences and questions

[Linus Torvalds]

On Tue, Jul 11, 2017 at 6:57 AM, Matt Thompson <mathomp at gmail.com> wrote:
>
> The Aeros 300CS, the Oceanic VTX, and the Aqua lung i750TC are all basically
> the same computer, all manufactured by Pelagic Pressure Systems, all
> suitable for grooming ;). They also all do BLE, hopefully the same flavor.
>
> I have screenshots of my i750 from nRF Connect that I can send to the list
> tonight when I get to my hotel.

I actually have an Aeris A300CS, and hated it with a passion. The
screen turns into a mirror underwater, and it doesn't have all the
data I want on it, and the "secondary screen" (which you get to with a
button press) ends up having such a small font that together with the
mirror-effect, it was completely unreadable.

Plus the battery only lasted for a couple of days of diving in my
experience (admittedly, that may have been a "five hours underwater
each day" trip). And that was with the default screen brightness
(60%?). If I had been forced to actually rely on it, I would have had
to up the brightness to 100% and probably thus lose even more battery.

So I was singularly unimpressed. I had it with me for one dive trip
and never touched it again.

Maybe I had a dud. Maybe they fixed the shaving mirror effect in the
VTX. Or maybe there's just something wrong with me, but I really
didn't like the A300CS even though I really wanted to.

Annoyingly, it seems like I have lost the tank sensor for it. And I'm
annoyed mainly because I think that tank sensor would work with my
Perdix AI.

ANYWAY.

After that rant, I can report that I did take a quick look at the
A300CS BLE, and it should be something we can support.

The thing uses a Blue Radios "nBLUE" bluetooth chip that implements
serial over BLE GATT (yet another "the standard didn't make a standard
serial protocol, so we made our own". Damn to hell all the f*cking
incompetent morons on the bluetooth committee).

Oops, I'm ranting again.

ANYWAY #2.

The good news is like the OSTC3 chip, that nBLUE chip is actually
documented, because it's used in various random IoT projects. For
example

  http://www.byteworks.us/Byte_Works/Blog/Entries/2012/12/28_Build_Your_Own_Bluetooth_low_energy_based_circuits_using_the_Blue_Radios_BR-XB-LE4.0-S2.html

and anybody with a bit of time and the lack of good sense to avoid BLE
programming could probably implement that in subsurface.

Can you verify that the nRF information from your i750TC matches the
UUID's on that web page? Because that's what my A300CS had - if they
are different, we're not going to have exactly the same BLE code..

I currently lack the time, but in another week or two I *might* be
able to look at it more if somebody else hasn't beaten me to it.
Because I clearly lack the good sense to stay away from BLE.

                      Linus