[Gta04-owner] GTA04A3 Testing Status Update

[Dr. H. Nikolaus Schaller]

Hi all,

over the weekend we tested back and forth and were
not able to make the UMTS module wake up. Only three
times we had strange signal forms on one output and
the module did draw sporadically changing current.
So it looked like it tried to startup but failed.

And, after removing the shield, we found some capacitors
within the module that are connected to our battery. But
the resistance of this connection was around 300 mOhm.
Which is much too high for those big pads and wires.

Therefore, we did reflow solder the module this morning
again. With more energy and higher peak temperature.

And voila, the module identified itself on the USB bus!

Then, we had to fix the software again (our 2.6.32 version
of hso.c does not yet have the module id in its tables). But
after using the "new_device" feature we could access
the AT command channel through /dev/ttyHS4.

And just 30 minutes ago - after inserting the board in
a Freerunner case *with* GSM antenna - I was able to
enter PIN, ask for active and neighbouring cells and
finally was courageous enough to issue an ATD command.

3 seconds later my POTS did indeed ring...

So we finally have reached a major milestone of
hardware validation! USB interface works, SIM works,
Antenna has some sensitivity and the module can
even emit GSM signals.

Now, I am not sure if we still can and should try to catch
the production slot this week or wait 3 more weeks with
production and do many more tests.

If we can get the units produced, we would have them on
Monday or Tuesday. But some areas are still not completely
tested and may malfunction. These are:

* Bluetooth / WLAN
* Camera
* Audio PCM of the UMTS module
* Battery charging
* some other minor areas

And since everything is done in a hurry, we will not be
sure how many of the units will finally work and how
many will fail.

What do you think? Should we
a) hurry and have all of you help testing (but low chance
     to repair) or
b) continue testing in our small team on two boards.
    Ensuring that almost every bit and piece in hardware
    works (not necessarily optimized, but works)?

Nikolaus

PS: thank you very much for all the donations! This will
certainly help to finalize development (which needs
to do some more tests, especially for the RF parts).
And, we may still have some broken boards to be
repaired.


Am 23.07.2011 um 10:42 schrieb Dr. H. Nikolaus Schaller:

> Hi all,
> I have good news and bad news. As usual,
> 
> a) good news first:
> 
> 	the DM3730 CPU is working fine :)
> 
> We had to fix some PinMux settings and initialisation
> in X-Loader and U-Boot, but yesterday I received the
> first board with a UMTS module!
> 
> 	http://download.goldelico.com/gta04/images/DSC00977.jpeg
> 
> This board has all components as the final GTA04.
> 
> b) bad news:
> 
> 	the UMTS module does not respond on
> 	the internal USB2.0 :(
> 
> It is not even clear if it is initializing and running its firmware.
> 
> Currently we have no idea why and have not found
> a way to debug it. What we don't know is, if we did some
> mistake in hooking it up to the CPU or if it was badly
> soldered or even was damaged during soldering.
> 
> This crumbles up the schedule again :(
> 
> The plan was to have this "golden master board" working
> by yesterday and then produce the Early Adopter boards
> next week.
> 
> But we can't start production before we know what the
> problem is. Unfortunately, the production company will
> have 3 weeks of holidays after next week. So unless we
> find a solution over this weekend, we will have to wait until
> end of August :(
> 
> One test we can do on Monday is to solder some wires directly
> to another module. I.e. we don't reflow the whole module and
> have more access to all signal pads.
> 
> But it is not clear if this already breaks the schedule. And
> experiments like this also strain our development budget.
> 
> Well, the budget already became quite low due to all these
> delays and many reworks.
> 
> So I would like to ask for some financial support. One option
> is to donate:
> 
> 	http://www.handheld-linux.com/wiki.php?page=GTA04-Early-Adopter
> 
> (at the bottom of the page "Just a donation...").
> 
> Another good help would be if you could consider buying or
> recommending this nice MIPS based mini-book from our shop:
> 
> 	http://www.handheld-linux.com/wiki.php?page=Letux%20400
> 
> It is not the most modern one, but amongst the cheapest ones and
> with 670g really light weight. Some guys also have a working 2.6.31
> kernel for this machine so that Debian Squeeze can run.
> 
> We can also provide the schematics so that you can e.g. add
> an external access to the I2C bus or whatever ideas you have.
> 
> Getting rid of the remaining stock without scrapping them would
> contribute a little to the GTA04 project.
> 
> Sorry that I don't have good news only,
> Nikolaus
> 
> 
> PS: if someone is interested in internal details of the UMTS module
> (which appears to be the same chipset as used in the iPhone 4),
> start to search the web for "Gobi 3000" or "MDM6200". Or go to
> http://transition.fcc.gov/oet/ea/fccid/ 
> and search for NCM / OMO6012
> 
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