[Gta04-owner] Can umts start powered off GTA04

Dr. H. Nikolaus Schaller hns at goldelico.com
Tue Nov 29 16:21:36 CET 2011

Hi Radek,

Am 29.11.2011 um 15:02 schrieb Radek Polak:

> Hi,
> is it possible to turn off whole GTA04 except UMTS module. And can then UMTS 
> start phone when some event comes, e.g. phone call?
> My plan is to keep only UMTS alive and when phone call comes, it will do very 
> fast boot so that i can answer the call.
> It can be temporary solution until power management is working well, but i 
> could use it also regulary e.g. on bike trip when i want to save battery as 
> much as possible, but i dont want to miss calls/SMS.
> Is something like this possible on GTA04?

Unfortunately not as you plan it and especially not on the
EA boards (which have a non-reworkable hardware bug).

We think we have fixed that in the GTA04A4 board but can
test it only if the first board come from production. If it does not
work, we have to scrap the remaining PCBs and redo them :(
But likelihood is low.

In detail:

1. yes, the UMTS module can basically send a "wakeup"
on a phone call and SMS. But it is not enabled within
the module. We are currently trying to find out how that
could work.

2. this signal can't power-on the CPU after a full "halt".
But it can generate an wakeup-interrupt to the CPU if it is in
suspend mode. This of course requires that we have
power management and all not required power consumers
are completely switched off during suspend. 

Or we will not come down to the 3-10 mA standby
consumption of the module.

3. The bug is that the CPU can't completely switch off
the module. I.e. we don't have a real "power off". It
will only happen if you either take out the battery or
if becomes drained by the UMTS module (3-10 mA).

We are working with the distributor to get more information
on all this, but that may need some time.

And, it is better solved in the GTA04A4 boards.
Maybe we find someone who sponsors a
A4 board for you that you can develop.


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