[Gta04-owner] GTA04 testing status
neiljerram at gmail.com
neiljerram at gmail.com
Tue Jul 5 10:19:10 CEST 2011
I can wait, and I am full of admiration for you doing this amazingly difficult work. Also thanks for another detailed update.
From: "Dr. H. Nikolaus Schaller" <hns at goldelico.com>
Sender: gta04-owner-bounces at goldelico.comDate: Tue, 5 Jul 2011 10:02:11
To: List for communicating with real GTA04 owners<gta04-owner at goldelico.com>
Reply-To: List for communicating with real GTA04 owners
<gta04-owner at goldelico.com>
Subject: Re: [Gta04-owner] GTA04 testing status
And just a few notes from the lab...
1. Soldering issues
We have four boards (two in "module" configuration
and two in full GTA04 configuration). Out of these
four only one did not show any soldering issues. I.e.
25% yield. This is a little low and we have sent one board
to X-Ray inspection to better understand this problem.
The issues appear to be short circuits of power supply
lines to GND. Two times under the WLAN/BT module
and once under the CPU.
2. Modem / Internal USB
it took 3 days experimenting with the kernel drivers
to find out that the USB3322 controller chip did
not respond at all. Because it was not optimally
soldered and had no power supply.
It took so long to find since it is a subsystem hidden almost
completely from the kernel. Because it is connected
through ULPI to the EHCI controller. And the kernel
only configures and handles the EHCI controller. And there is
no error message - the interface simply appears to
have no devices plugged in. After digging deeply into
data sheets and kernel driver code we were able to
add code to directly read the ULPI registers - and
it turned out there was nothing to read (all 0x00).
After heating the chip for reflow it now works well and
we can see USB test signals at the pads where the
UMTS modem will be connected.
Next step will be to solder a USB socket and connect
some device and check if it is recognized with lsusb.
3. Sound (ALSA)
we have the headset working and the Earpiece.
Sound quality appears to be very clear.
And even the Vibrator motor can be enabled
to "play" the sound.
Where we have found a problem is the handsfree/
music speaker amplifier. There, we have soldered
wrong capacitors. This has the effect that we can
see some signals on the oscilloscope if we disconnect
the speaker. But it is not audible at all. Next step is
to replace these 4 capacitors.
Recording (internal microphone or headset) hasn't
been evaluated yet.
So hardware validation is a slow process which sometimes
reminds me of the old ages where you had to punch
your software onto a deck of punch cards. Deliver it
in the evening to the computer center which worked
through them over night. And only next morning you got
the syntax errors from your FORTRAN compiler. Then
you could fix something and had to wait until next morning.
Our university did still run such a system so that we still
could experience that - even in the ages of Unix and PCs :)
Now, we would like to find the most critical problems
before production of the Early Adopter units starts.
I hope you can still wait some more days...
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