Sansа Clip Zip - Improve battery life

[saratoga]

Checked -  no significant difference at pause, low volume (-35dB) and high (0dB).

AVDD17 or 27?  I think 17 is the line out and mixer, 27 is the headphone. 

[Mihail Zenkov]

AVDD17 or 27?  I think 17 is the line out and mixer, 27 is the headphone. 

For both.

Testing CVDD2, it seems that PVDD1 is derived from it

AVDD17 derived from AVDD27.

If someone interesting: SD card 32GB class 10 eat 0.6mA 

[[Saint]]

Freenode offers an IRC web-client, as linked on the left hand side of the page.


[Saint]

[saratoga]

I tested battery life on some builds:

Last spring: 10h 14min
Current git: 13h 35min
Current git + 1.1v CPU (no change to other clocks): 15h 0min

[oid_maps]

rockbox-backlight.patch: disable DCDC15 when screen off (save 1mA), like we already do in Clip Plus. Good for inclusion in main branch.

Thanks;
is that so special to the Clip Zip, or is it easy to adapt to other Sansa devices?

[Mihail Zenkov]

is that so special to the Clip Zip, or is it easy to adapt to other Sansa devices?

I suppose we need check each device for optimal frequency/voltage for best result and stability, but it should by mostly same. In any case at first we should check and fix frequency scaling and push it in to main branch. Then we can adapt it to other device.

[Mihail Zenkov]

Current git + 1.1v CPU (no change to other clocks): 15h 0min

Is 1.1V lower stable voltage on 240Mhz?

[oid_maps]

is that so special to the Clip Zip, or is it easy to adapt to other Sansa devices?

I suppose we need check each device for optimal frequency/voltage for best result and stability, but it should by mostly same. In any case at first we should check and fix frequency scaling and push it in to main branch. Then we can adapt it to other device.

I was about the backlight-patch. I thought that it was clear because I cited just that part.

[saratoga]

Current git + 1.1v CPU (no change to other clocks): 15h 0min

Is 1.1V lower stable voltage on 240Mhz?

Yes, but 1.0 was not.  I was mostly curious to see how important voltage was to runtime.

is that so special to the Clip Zip, or is it easy to adapt to other Sansa devices?

I suppose we need check each device for optimal frequency/voltage for best result and stability, but it should by mostly same. In any case at first we should check and fix frequency scaling and push it in to main branch. Then we can adapt it to other device.

I was about the backlight-patch. I thought that it was clear because I cited just that part.

The backlight patch is already committed, and (as per the first post), specific to the Zip. 

[Mihail Zenkov]

New version with frequency scaling based on as3525v2-cpufreq-v11.patch.

[saratoga]

I'm curious how stable frequency scaling is for you?

[Mihail Zenkov]

Few hours playing APE (switch freq each second). I try find way switch PCLK to master clock or PPL but no success. Have any idea on how we can do this?

If you have freeze with this patch first try remove set CVDD1.

[Mihail Zenkov]

I try new solution - don't switch PCLK. In this case at normal frequency we have FCLK 40MHz / PCLK 20MHz, at boost - FCLK 240MHz / PCLK 120MHz. It very stable for me: 12 hours of APE and two day of ordinarily use without any freeze. Possible it slightly less effective, but not sure - decoding at PCLK 120MHz work faster and we need less time in boost mode.

[saratoga]

I try new solution - don't switch PCLK. In this case at normal frequency we have FCLK 40MHz / PCLK 20MHz, at boost - FCLK 240MHz / PCLK 120MHz.

Are you sure about that?  Max PCLK is 60 MHz IIRC, and when we tested, raising PCLK increased power consumption a lot more than raising FCLK (because many things on the chip also increase in frequency).

[Mihail Zenkov]

Are you sure about that?

Yes.

Max PCLK is 60 MHz IIRC, and when we tested, raising PCLK increased power consumption a lot more than raising FCLK (because many things on the chip also increase in frequency).

It increase power consumption a lot (+4.3mA) if we compare idle and much less difference if we have load: +2.5mA on light load (playing mp3). At full load I suppose (no measure it) it have no significant difference or may have better result than low PCLK.