ichgeh at l--putt.de
Mon May 16 22:09:13 UTC 2011
Some time ago Harald suggested to create a complete phone, at least with
minimal features. Since this hasn't been covered yet and we will have to
rewrite some parts during RTOS porting anyway, I think we should
consider some kind of power management:
Having everything on and at maximum clock drains the battery _fast_!
With the ULPD, we actually have the appropriate solution build into the
Calypso. I guess other chipsets have something similar.
It is neat to get the timing and power sequence right. But since the
TDMA timing is affected, Layer 1 must be aware of those clock/power
changes or at least tolerate to be turned on and off. Does anybody right
away have ideas how to approach this?
The C155 has a dedicated chip which you probably just have to turn on.
On the C123, it's a bit more complex but the algorithms don't seem to be
too complex. Has anybody tried this already?
For the usual concepts on batteryuniversity.com, a random book from the
university lib, and some papers, we would need some means to measure the
discharge current. No Compal phone provides this since the voltage
regulators are connected directly to the battery. The gta02 avoids this
with a dedicated Coulomb-counting chip. The gta01 doesn't care!? Maybe
the battery voltage and temperature is sufficient for reasonably correct
estimates. If not, we could try to model the current. However, this
requires some kind of central power management that knows activated
devices, their clocks, etc.
I would volunteer for the latter and C155-charging. However, I lack a
C123 for tests and don't want to be responsible for exploding phones ;)
Integration of the ULPD is a bit more GSM-related. Might turn out to be
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