[Tinkerphones] Librem 5

H. Nikolaus Schaller hns at goldelico.com
Tue Oct 24 22:13:53 CEST 2017


> Am 24.10.2017 um 22:01 schrieb jake42 <jake42 at rommel.stw.uni-erlangen.de>:
> 
> On 24.10.2017 21:46, H. Nikolaus Schaller wrote:
> 
>> Opinions?
> Or rather questions.

Let's try to find answers...

> Is there a power-saving state for a mobilephone use case which
> works on OMAP5?

Basic suspend works (I have tried on the Pyra).

> How big a battery would it need to be able to use it for two days mostly in standby registered to the network?

That mainly depends on suspend current consumption.

The modem itself draws ca. 3-10 mA while being able to detect incoming calls and awake
the system.

The most critical thing is suspend to RAM which needs to have the DDR3L in self-refresh.
I have no idea if that works and what the current consumption is.And if all other peripherals
have proper drivers to power down. We know from the GTA04 that there might happen strange
things.

So let's assume 100 mA in suspend... With a 3000 mAh battery this gives 30 hours which is
not enough for your 48 hours wish. So we must get <62mA. No idea if that can be done or not.
On the GTA04 we typically got 50mA and sometimes 25mA. But that was with LPDDR and not
DDR3L (which is more power hungry).

But I am quite sure nobody from the Librem 5 development team can answer the same question
for the i.MX8.

BR,
Nikolaus




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