[Gta04-owner] Latest progress

[Dr. H. Nikolaus Schaller]

Am 04.08.2011 um 12:45 schrieb Butrus Damaskus:

> On Thu, Aug 4, 2011 at 11:28 AM, Dr. H. Nikolaus Schaller
> <hns at goldelico.com> wrote:
>> Hi all,
>> here is some progress update:
>> 
>> * we have received 5 more boards from the fab:
> 
> Good Job! :-)

Tnx.

> 
>> http://download.goldelico.com/gta04/images/IMG_0112.jpg
> 
> Just curious: what are the parts that are missing on the backside (or
> is it frontside)?

it is the "frontside" where the display will be. But we still name it the
bottom layer :)

The spare positions are two B2B connectors (if the board is used
as a module to sit on a motherboards), a position for a LSM303
compass/accelerometer. This is not needed since we have a better
combination of a HMC5883L and a BMA180 (on the other side).

And, there is space for a 8x10 keyboard controller (TCA8418). And
a VGA DAC. But that one draws too much current and we have not
found a way to integrate a VGA connector so that it still fits into the
Freerunner case. Finally, there is room for some U-FL sockets.

Therefore, these positions are not used and most can only
be used if there is no display module connected.

>> * a first quick test did show that 3 of them boot to the login: prompt
>> * 2 of them don't boot
>> * so we have still some production problem to iron out
> 
> Do you have some hypothesis what can be wrong?

Either missing contacts or short circuits between BGA balls
like this one:

http://download.goldelico.com/gta04/images/xr002.jpg

(innermost ring between 2 and 3 o'clock).