Am Wed, 12 Feb 2014 10:28:46 +0100 hat "Dr. H. Nikolaus Schaller" hns@goldelico.com geschrieben:
Hi,
Okay... the I'll check the reference guide to see which ones I need to use tol test it.
Another idea is to break into U-Boot console and measure then. Most certainly it is running in single core low clock (300 MHz?) mode.
Hm, it uses 2W straight when I switch it on, doesn't sound like single core 300MHz...
U-Boot has no power management - except low CPU clock.
So the additional power management features will lower the power consumption even when using the clockspeed?
I thought they'll just lower the clockspeed when it's not used.
Just came to my mind - is it possible to disable/enable cores on-the-fly?
So can we switch to single core / dual core mode while running?
If I remember correctly my first experiment the whole EVM did draw ~400mA at 5V.
Same here, which would be the 2W in idling I was talking about.
It is the same as an OMAP3 (BB or GTA04 values) draws in idle mode. This means unless there is power management, the CPU enables all clocks for all system components. By switching off some parts it is possible to get it down to 150-200 mA.
Okay. Do we know whether power management mode is enabled in our current kernellll?
You must go to "suspend" mode or an improved power management scheme to get below.
Well, suspend is not usable when running ;)
I get about 10 hours battery life with a Pandora and a 15,84Wh battery. The same should be possible with the Pyra when running approx. the same speed. It should still be 7 - 8 hours when doing some advanced stuff, but hopefully, it shouldn't be less than 5 hours.
Otherwise, I'll really thing about changing the battery... Or we put another battery behind the LCD :) Then people could change one battery on-the-fly, and as the LCD is so thin, it wouldn't even affect the lid thickness tha much :P