Sansа Clip Zip - Improve battery life

[johnb]

If you could provide a build for the fuze v2, I could do the testing.

Cheers
johnb

[saratoga]

You could try this:

http://web.mit.edu/mgg6/www/rockbox-fuzev2.7z

Its untested though. 

[johnb]

I did a clean install, i.e. removed the existing .rockbox.
It is practically unusable for me. I usually end up with one of the two situations:

• The UI freezes.
• I get an error like:
  undefined instruction at 300C7BF8
  pc: 300C7BF8 sp: 308049E0
  bt end
  

For the freezing I have the impression, that as long as I keep going (scrolling through the main menu) it's ok, but as soon as I pause for a few seconds and try to scroll again, then it get's stuck. Going into the file menu then usually freezes.
Starting from the recent bookmarks I was able to listen to music (flac, Opus 64 & 220, mpc , mp3, aac), no issue audio wise, but no exhaustive testing.
Once I managed to get to the Debug->Frequency page and noticed that the boost level stayed at 1.


All the above was when doing a fresh boot. Coming from USB mode it at least once was way more stable: going through menus, picking other songs, changing settings.
Looking at the boost level I saw it switching.
It then finally stopped with one of the 'undefined instruction' errors.

[Mihail Zenkov]

johnb:
Thanks for report!

saratoga:
I think we should try remove CVDD1 for normal mode in build for fuze v2.

[saratoga]

Constant CVDD1:

http://web.mit.edu/mgg6/www/rockbox-fuzev2.7z

[saratoga]

Looking at the as3525 datasheet, I think we are clocking the DBOP too high due to increased PCLK, and the DBOP is accessed during LCD update, so lets try lowering it:

http://web.mit.edu/mgg6/www/rockbox-fuzev2_2.7z

[saratoga]

Setting PCLK to 64MHz fixes the problem on my Clipv2. 

Edit:  Heres a Fuze v2 build with the lower clock.  Would also be interesting to know if this one works:

http://web.mit.edu/mgg6/www/rockbox-fuzev2_64MHz.7z

[Mihail Zenkov]

Setting PCLK to 64MHz fixes the problem on my Clipv2. 

Good. Did you try set bigger divider for DBOP with PCLK=96MHz?

Edit:  Heres a Fuze v2 build with the lower clock.  Would also be interesting to know if this one works:

If I understood right, fuze v2 have problem only when boost = 0.

[johnb]

Constant CVDD1:

http://web.mit.edu/mgg6/www/rockbox-fuzev2.7z

Same behavior: scrolling through the main menu the screen freezes (to be more precise about 'freezing': screen doesn't change anymore, but could also be that the scroll wheel doesn't respond anymore. However, no other timeout kicks in, e.g. screen backlight or wheel light).

[johnb]

If I understood right, fuze v2 have problem only when boost = 0.

For me, I have never seen it go to 0. In my report above in one case it always stayed at 1; when I saw the switching it was between 1 and 3.
frequency always at 192.


Edit: I just retested the 'Constant CVDD1' version: coming from the USB unplug, I am able to start a song from the Files menu. Going to Debug-> Frequency it is at 384 MHz and boost changes in a range from 0 to 5, but then after a while a crash with
SWI at 301c465c
pc: 301c465c  sp: 300A6728
bt end

[johnb]

Looking at the as3525 datasheet, I think we are clocking the DBOP too high due to increased PCLK, and the DBOP is accessed during LCD update, so lets try lowering it:

http://web.mit.edu/mgg6/www/rockbox-fuzev2_2.7z

That was a quick test:
Firmware update, USB unplug, Rockbox asks if it should reboot due to the new firmware -> yes:flickering display, stays in rolo-> screen goes white


Restart, stays in Rockbox boot screen: Boot Vers. 4.0, display turns off due to timeout, moving wheel ->  Boot screen blends into grey screen

Restart by plugging USB  ->screen goes grey/ white

USB connection sometimes works, sometimes doesn't. At least I was able to replace the .rockbox folder without booting into the original firmware.

In short: even worse than the first build, since I don't get out of the boot screen.

[johnb]

Setting PCLK to 64MHz fixes the problem on my Clipv2. 

Edit:  Heres a Fuze v2 build with the lower clock.  Would also be interesting to know if this one works:

http://web.mit.edu/mgg6/www/rockbox-fuzev2_64MHz.7z

Reboot question: yes. Stays in 'Rolo executing'. Screen timeout.Scroll wheel -> white screen.

Power down. Fresh reboot: Stays in Rockbox logo/ Boot Ver. 4.0 screen.  Need to power down.

Connecting to USB: USB symbol appears, drive mounts. Screen timeout, moving wheel turns on grey screen or fades from Rockbox logo to grey screen. USB still works.

Edit: Since I just noticed that I had created some recordings in the root dir, I figured that navigation somehow was possible even though I was still in the logo screen.
So new trial: I prepared a track that I could easily navigate to blindly. Rebooting, I can navigate to the song eventhough I still see the Rockbox boot screen. After starting the song, volume change and skipping to the next song is possible. The screen is alive though distorted. Moving the wheel - thus changing volume- every now and then the screen updates and I can see an undistorted WPS screen. Triggering any further update it distorts again.

[saratoga]

I think devices with a wheel will boost whenever the wheel is used.  Here is one more build:

http://web.mit.edu/mgg6/www/rockbox-fuzev2_64MHz_2.7z

[johnb]

I was about to say this is the most stable one. Tried the following:

1. Boots properly into the main menu. Browsing the main menu  with the wheel for a while, it freezes.

2. Reboot, go immediately to Files and select the first song, it plays. From WPS trying to go to Main Menu/ System it crashes:
undef. instr. @ 300C7BF8 sp: 308049E0

3. Again going directly to Files and play a track, in WPS I am fine: screen updates (long title scrolling, track time counting), FF, pause, resume, screen turns off and on again on activity, track skipping back and forth.
From WPS going to the file browser (center button), playback stops with some crackling noise, then freezes and silence.

4. Boot into main menu, just scrolling for a while, going into the settings menu.
The wheel is very sensitive, don't manage to select the General Settings for a while, cursor rather jumps. Finally I manage to hover over the General Settings, but neither middle button nor right click does anything.
Finally freezes.

5. Again happily in the WPS. Using the Home button to invoke the Playlist, selecting the next track it crashes:
undef. instr. @ 30804A6C sp: 308049A4
Screen turns off.

And this is where I take back the 'most stable' statement. I am not able to power down or reboot (>30s power button; USB connection, ....)

Inserting the headphone I hear two clicks, so I hope it's just not responding and will wait for the battery to drain :-(

[saratoga]

Usually if it crashes bad like that it will eventually reboot if you keep holding power, although it can take a while.

To summarize testing:

Zip:  Works fine.
Clip+:  Seems to be working, but needs slightly higher voltages on some devices.
Clipv2:  Will not work at PCLK = 96MHz, but 64 MHz works fine (verified on skips device as well).
Fuzev2:  Lowering PCLK helps, but does not solve the problem.

Since 64MHz works, but 96MHz seems limited to newer models, I wonder if some of the earlier revisions of the 3525v2 had the v1's limit of 65MHz for the PCLK.    Would be interesting to know how much highe PCLK can go on the Zip too, in case we are already out of spec.