[Gta04-owner] CPU, Memory

Dr. H. Nikolaus Schaller hns at goldelico.com
Wed Mar 2 11:55:21 CET 2011


Hi all,
I think it is time for a short update...

a) Components
The memory chips have arrived just 10 minutes ago.
And the TPS65950 is already here.

So we still have to wait for the CPUs.

And,

b) the PCB layout.
Here we have much slower progress than anticipated.

As mentioned before, we have found the reasons for
the power supply issue of our first sample board. It
have been too small and too long wires in the DC/DC
converters (which provide up to 1.4 A at 1.2 V) from
the 3.2-4.2 V battery.

So we had decided to completely rework the PCB layout
and also include shielding and tunnels for the most
critical audio signals. This has been completed and
then we did run the Autorouter for the uncritical parts.

Unfortunately we did not get beyond approx. 95% completion
so far. This means that approx. 90 connections
are still unrouted. And routing them manually with the tools
we have (we use EAGLE professional) is quite painful and
very time consuming.

We also have looked into KiCAD but it did not appear to
be mature enough for such a complex and miniaturized
project and would run into the same mode of manually
editing.

Well, there are high price commercial tools (Altium, Cadence, Mentor, ...)
which could be better supporting this work, but converting
the existing EAGLE project into a file compatible to those
may loose important information/knowledge/design rules
and may introduce new costly errors.

Therefore, we are continuing the slow manual path staying
with EAGLE... The good side is that we already know
that there are no problems in post-processing and
production based on the EAGLE files because we have
done this several times with our PCB supplier. This
is also an area were experiments are quite costly.

I hope you stay with us and support our project,
Nikolaus



Am 07.02.2011 um 17:39 schrieb Dr. H. Nikolaus Schaller:

> Hi all,
> I now have all quotations and will order the CPUs and Memory chips tomorrow.
> 
> We will get:
> 
> * MT29C4G96MAZAPCJG-5 IT (512 MB RAM, 512 MB NAND Flash)
> * DM3730CBP (unfortunately the 800 MHz version - the 1 GHz won't arrive before July and that is too long to wait)
> * TPS65950A3 (latest version of the power controller)
> 
> Let me add that our FOSDEM presentation last weekend did draw a lot of
> attention and people like the idea (as you already did) and we did receive a
> lot of encouragement to continue!
> 
> For FOSDEM I had made some "GTA04" T-Shirts for our FOSDEM presentation
> and we were easily recognised :) Photos how we look wearing these T-Shirts
> should become available soon.
> 
> 2 of these T-Shirts are left over (one in "M" and one in "L"). They did cost me
> 16.20 EUR (incl. shipment) in production. Shipping cost to you depends on
> destination of course.
> 
> if there is interest in having more, we can set up some T-Shirt-Service where
> you can order directly in your preferred size. And add GTA04-tea&coffe cups
> etc. :)
> 
> 
> Nikolaus 
> _______________________________________________
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> Gta04-owner at goldelico.com
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