[Gta04-owner] GTA04A5: you will hate and you will love this mail

Thierry GRAUSS tgrauss at f-gp.eu
Thu Feb 11 18:24:59 CET 2016


Hi,

Good to know that it is not that much late.
It is always a good think to take a little bit more time but have
something rock solid and better.

Concerning the wifi chip, sure 20 euros is a lot more for just adding
the 5GHz band, but on the other hand it will help to have a future
proof phone (if we must connect to a 5GHz only router in the future, it
is a good thing to have the capability).

Also, as it adds 20 euros, you should ask everyone who have already
paid for the phone if he/she wants to pay for this.
In my case, I would like the WL1837 to be future proof. Is it possible
to have a few with the WL1835 and some other with the WL1837? I don't
think so because of the setup of the pick and place machines, but I
might be wrong about this.

Best regards

Thierry


 On Thu, 11 Feb 2016 17:37:20 +0100
"H. Nikolaus Schaller" <hns at goldelico.com> wrote:

> Hi Neil, hi Thierry,
> 
> Am 11.02.2016 um 17:02 schrieb Neil Jerram <neil at ossau.homelinux.net>:
> 
> > FYI this is a bit 'tl;dr' for me.  Actually I did read it quite
> > well, but still struggled to see the overall message
> 
> ok, sorry for that. It always happens if you collect a lot of
> information but don't have enough time to write a well-designed
> posting.
> 
> > - GTA04A5 is still alive but will
> > take longer than planned?
> 
> Yes. A longer that planned and last time announced, but not much.
> 
> In fact to answer the question of Thierry, there is a good chance
> that the final order for production can be done as early as by end of
> next week. There isn't much to be done (some paperwork,
> checking/improving the PCB layout for another time, testing the 1GB
> RAM chip).
> 
> How long it takes to get the remaining components is guesswork but
> ~4 weeks until the first PCBs can be built is a good guess.
> 
> There are only two open questions:
> * RAM verification which needs us to succeed in replacing a RAM chip
> in an old GTA04
> * WL1835 or WL1837? The latter being ~20 EUR more expensive but
> having 2.4GHZ / 5.8 GHz
> 
> What are your opinions on the WL1835/37?
> 
> BR,
> Nikolaus
> 
> > 
> > So, please consider adding a summary.
> > 
> > -----Original Message-----
> > From: gta04-owner-bounces at goldelico.com
> > [mailto:gta04-owner-bounces at goldelico.com] On Behalf Of H. Nikolaus
> > Schaller Sent: 10 February 2016 19:28
> > To: List for communicating with real GTA04 owners
> > <gta04-owner at goldelico.com>
> > Subject: [Gta04-owner] GTA04A5: you will hate and you will love
> > this mail
> > 
> > Hi all,
> > you might wonder what the status of the GTA04A5 is.
> > 
> > Unfortunately there has not been much progress since I had to spend
> > much more time on making the Pyra (OMAP5) hardware working and
> > verifying that it is indeed mass production ready than anticipated.
> > This was really exhausting because it was squeezing a phase that
> > would normally need several months into just some weeks.
> > 
> > There had been a lot of details to be fixed. Not much if you see
> > the result, but each issue needed 110% attention for several days
> > until a reliable fix was found (and some are still open). For
> > example, there were boot problems, where the Linux did sometimes
> > start to boot, but suddenly stopped. Sometimes it reported CRC
> > errors.
> > 
> > This turned out to be a 15pF capacitor to attenuate the MMC clock
> > signal since it may disturb the GPS receiver (63th harmonic of the
> > 25 MHz clock). A lesson we learned twice for the GTA02 and GTA04.
> > 
> > But this time the 15pF was good for GPS but too much for the MMC.
> > It made the MMC interface of the OMAP5 to fail spuriously. Such
> > bugs make grey hair and need a lot of time - and can't be
> > parallelised by having more people to work on it.
> > 
> > But now, we are almost through and the OMAP5 is starting to work
> > reliably.
> > 
> > This has a nice side-effect, which is very important for the
> > GTA04A5 project and the reason why I report it today.
> > 
> > The GTA04A5 needs some replacement components because the old ones
> > used in the GTA04A3 and A4 are no longer available. Even for money.
> > 
> > One of them is the WLAN/BT combo W2CBW003.
> > 
> > So the plan is to replace it by a modern WL1835 module [1] which
> > adds more WLAN frequencies, speed and adds Bluetooth BLE 4.0.
> > 
> > But it would be risky to throw it into the schematics, make a PCB
> > layout and build the ~100 GTA04A5 we have on plan. The risk is that
> > it does not work and we have no chance and money to fix.
> > 
> > Fortunately, the Pyra also has such a module :) And yesterday, I
> > was able to get it alive for WLAN and today for Bluetooth. This
> > means that the way it is wired up to the OMAP5 MMC4 interface and
> > UART2 is working!
> > 
> > And, the way the setup is done in the Device Tree also works.
> > 
> > Since the OMAP3 is not different for these interfaces, I am now
> > sure that we will not make a mistake if we throw in the WL1835 into
> > the GTA04A5. This is the good thing! It simply will work with the
> > 4.5-rc3 kernel (and slightly different commands in user space).
> > 
> > The other decision blocking the GTA04A5 production is the 1GB
> > RAM/NAND chip. Before deciding to solder them all on the ~100
> > GTA04A5 boards, I would
> > 
> > like to test it a little with some old (partially broken) GTA04
> > board. This means desoldering the original 512 MB PoP (Package on
> > Package) RAM/NAND chip. But without damaging the DM3730 CPU. And
> > then solder the different PoP chip on top [2].
> > 
> > Desoldering is easy (since we now have a new vapour phase machine
> > with BGA desoldering tools). But soldering a new chip, especially
> > Package on Package is really tricky. First experiments did make the
> > new chip swim away so that it was soldered in a wrong position :(
> > 
> > Therefore we have aborted that to find a solution. There are ideas,
> > but this needs more experimentation time (i.e. days) until it
> > becomes successful. Unfortunately another topic queued up behind
> > making the Pyra handheld production ready.
> > 
> > So I have to apologize that we can't keep the availability date,
> > but it is really not much missing. Except time to do what is needed.
> > 
> > I am really sorry for that delay which might come a little
> > unexpected since I did not even give some status updates in the
> > last weeks. This is something I promise to change again.
> > 
> > There is also something on the horizon: a Kernel and QtMoko hacking
> > weekend. The plan is to meet in some cosy place and have some core
> > hackers just work in two teams to fix remaining kernel issues on
> > one side and overhaul QtMoko to run on top of stock Debian Jessie.
> > Replicant will also be represented, and we hope that we can then
> > even use our Letux standard kernel for Replicant.
> > 
> > Please let me know if you want to participate/contribute.
> > 
> > And of course if you have questions about the GTA04A5.
> > 
> > A final note: we have a new mailing list for Letux kernel
> > development [3] so that this list does no longer need to be
> > cluttered by tiny details and patch discussions.
> > 
> > Sorry again for the delay and thanks for your patience.
> > 
> > -- Nikolaus
> > 
> > [1]: http://www.ti.com/product/WL1835MOD
> > [2]: https://en.wikipedia.org/wiki/Package_on_package
> > just a note: we have the "or less" variant in the picture: 0.5mm on
> > top and 0.4mm on bottom
> > [3]: http://lists.openphoenux.org/mailman/listinfo.cgi/letux-kernel
> > 
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> > 
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