[qtmoko] flight mode power consumption / turning gsm back on

Tue Aug 28 14:55:54 CEST 2012

On 2012年8月28日 08:21:20 -0400 Benjamin Deering
<ben_deering at swissmail.org> wrote:
> On 08/28/2012 07:44 AM, robin wrote:
> > hi ben,
> >
> > could you please give some more detail on how do you set it in woods mode?
> > and does the gsm power on afterwards correctly or do you have to restart the
> > phone?
> >
> > thanks
> >
> > robin
> >
> >
> > ps: here is the link to the paper on powerconsumption of the freerunner:
> >
> > http://www.ssrg.nicta.com.au/publications/papers/Carroll_Heiser_10.pdf
> >
> >
> > _______________________________________________
> > Openmoko community mailing list
> > community at lists.openmoko.org
> > http://lists.openmoko.org/mailman/listinfo/community
> >
> I use SHR most of the time, but the same thing should apply. I just 
> meant to change the GUI to call 'airplane mode' 'woods mode' because my 
> phones go in the woods and I don't fly very much at all. I suspect 
> something is wrong with airplane mode on both qtmoko and SHR for gta04 
> if airplane mode doesn't use less power. Transmitting would be the 
> biggest power draw and even if the modem remained powered up power 
> consumption should drop unless it is transmitting.
>> On gta02, I could turn 'airplane mode' off and on and it usually 
> worked. I never spent a lot of time watching power consumption on 
> gta02, but I did keep track of battery life. On gta04, we are still 
> figuring out power management and I had some charging issues so I was 
> dumping 'current_now' once a second in various configurations. A 
> somewhat unrelated thing I noticed and should report is that the 'idle 
> dim' state of fsodeviced actually uses more power. The process of 
> smoothly dimming the display wakes up the CPU and by the time it settles 
> back down, it is time to turn off the display anyway.
>> I didn't mean to steer this away from qtmoko, but I think most of the 
> power related issues we are seeing are happening at a low level and 
> apply to all distros.

On a GTA02 you power off the GSM chip by writing
 AT at POFF
to the modem. This definitely reduces power usage quite a lot.
You then typically write '0' to the 'power_on' and 'reset' sysfs files,
but that isn't so important I think.
If you are using gsm0710muxd, it will do all that for you when you tell it to.
You need to use some D-Bus command that I'm not familiar with.
Something like
 bus-send --system --print-reply --type=method_call \
 --dest=org.pyneo.muxer /org/pyneo/Muxer \
 org.freesmartphone.GSM.MUX.SetPower bool:false
maybe.
NeilBrown
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