Serious heat issue with Fuze V2

[yapper]

I can't see anything in the change logs?

Look here: http://svn.rockbox.org/viewvc.cgi?view=rev;revision=29896

[nexekho]

I don't happen to consider having the screen brightness maxed out for extended periods "normal use", also, it was not promoted to stable *after* this was discovered either. It was marked as stable well before then if I remember correctly.

When I installed it, it was an unstable build.  Within an hour, the problem surfaced and after a few more hours I posted here.  Since then it's been moved to "stable".  See my first post, I acknowledge that it was marked unstable.

Look here: http://svn.rockbox.org/viewvc.cgi?view=rev;revision=29896

Ah, thanks.  I'd expect changes to be listed, well, frankly, in the change log rather than having to pick through SVN.  Which I can't even find from the homepage.

Also, you must consider that this is *free* software

I know and I have.  I think Rockbox is amazing.  So much functionality, on hardware the developers likely don't have official documentation for is astounding.  I've even donated previously because I think the project is an accomplishment and deserves all the support it can get.

[gevaerts]

And just choosing a seemingly arbitrary number to cap the brightness at doesn't sound like a solution.  If I can have my brightness on full on original firmware, but we can't have it on Rockbox without blowing your device's power supply, it smells as if there's another more serious bug lurking and capping the brightness is just a sticking plaster.

How do you know capping isn't exactly what the OF is doing?

[nexekho]

I didn't notice any brightness difference between OF and Rockbox pre-cap, but that doesn't say much as it's hard to compare.  Maybe it might be worth someone with a device on which it works and a camera with custom exposure settings load a blank photo in OF at full brightness in a dark room and then find the equivalent in Rockbox to be sure.

[yapper]

Look here: http://svn.rockbox.org/viewvc.cgi?view=rev;revision=29896

Ah, thanks.  I'd expect changes to be listed, well, frankly, in the change log rather than having to pick through SVN.  Which I can't even find from the homepage.

It was listed on the front page (http://www.rockbox.org/) when it was first added. As the change was made months ago, you now need to scroll down to the SVN section (http://www.rockbox.org/recent.shtml#svn) and click the link for "all commits since last release" (http://www.rockbox.org/since-release.html).

[nexekho]

I've just installed RB, added a blank white image, maxed the brightness in OF, taken a photo with fixed WB/shutter speed/apeture/ISO settings on my S1500, and then played with the brightness in RB until the photos came out pretty much identical.  9 looks about right.  As a side note, it still produces a lot of heat although not as much as when my previous Fuze died.

[gevaerts]

I've just installed RB, added a blank white image, maxed the brightness in OF, taken a photo with fixed WB/shutter speed/apeture/ISO settings on my S1500, and then played with the brightness in RB until the photos came out pretty much identical.  9 looks about right.  As a side note, it still produces a lot of heat although not as much as when my previous Fuze died.

So (assuming this can be repeated on some more fuzes), the max. setting should be 9, and we'd be behaving the same as the OF?

[yapper]

I've just done some testing and my results indicate that the maximum OF brightness setting corresponds with 12 on Rockbox, and that brightness 20 in Rockbox exceeds the maximum brightness produced by the OF

I used F3.5, ISO64 and and monitored the resultant shutter speed:
Fuze Firmware on max brightness = 1/74 sec
Rockbox brightness 12 = 1/74 sec
Rockbox brightness 13 = 1/74 sec
Rockbox brightness 20 = 1/111 sec

[nexekho]

That's a very smart way to do it, I was just comparing the brightness by eye flicking between the two photos.  The viewing angle is probably quite important too as I was slightly off and my tripod isn't very accomodating of the angle I used.  I imagine it is a bit hard to notice as the default theme is considerably darker than OF's.

EDIT:
I just tried the shutter speed method, and found that on my camera (not a DSLR, just a high-end compact) with ISO 400 and F2.8, I get 1/640 for both 100% OF and 12 Rockbox.  So I can confirm the 12 value.  The heat seems to have stopped.

[yapper]

Maybe Gevaerts or another dev can shed some light on it, but if the Rockbox LCD code is simply writing the brightness value directly to a register, it would be logical that 1-12 on Rockbox would correspond directly with the 12 brightness steps on the OF.

[soap]

I don't happen to consider having the screen brightness maxed out for extended periods "normal use",

Really?  We ship with no warning/caution/advisory on the brightness setting, encourage extended use of the backlight through the inclusion of games, video playback and a bloody flashlight plugin, and you don't consider the situation "normal use"?  

also, it was not promoted to stable *after* this was discovered either. It was marked as stable well before then if I remember correctly.

Timing doesn't matter.  "Stable" as a label either means something or it doesn't.  If there is a known issue it should at least be published.

This is also not something that is happening with all of these devices, mine for instance are fine and I see no overheating.

Nobody is suggesting all have this issue.  This is clearly documented as not being an isolated incident.  Personal anecdotes notwithstanding.

The developers cannot be help responsible for testing every single circumstance that may arise in the usage of the device, as what is "normal" usage to you may not be to them.

Nobody is asking them to.  What is being asked is for a repeatedly reported issue to be shown due consideration.

To many people these are audio players, not flashlights or ways to play Doom etc. etc.

If Rockbox isn't a flashlight or Doom player then why do we ship that?

The developers also can't (nor should they) drop a port from stable to unstable based on problems that only a few devices are seeing. If that was the case then there would be very few ports (if any) that were "stable".

Citation needed.  Seriously.  Name another device with such serious hardware issues reported.

There have been limits set to (hopefully) prevent this overheating issue, but that's not to say that there are not as yet unknown variants of the hardware that will still be damaged by these new "safe" settings.

Are you seriously arguing that since we can't predict unknown variant's behavior we should ignore known variant's behavior?

Also, you must consider that this is *free* software, and under no guarantee whatsoever, it is a conscious decision you are making to install it and if your device is damaged or left in a completely bricked state after installation or usage normal or otherwise then that falls on you and not the Rockbox team.

Again, all reasonable people already know this and it is not the point in contention.  What is in contention is the reasonable response to these reports.

[gevaerts]

OK, I've now committed the necessary change. New svn builds will have 12 as the maximum (as of r30227).

I've also committed the change to the 3.9 branch, so if we release a 3.9.1, the change will be there as well.

[nexekho]

Thank you!  I'm sorry if I came across as a bit snarky and disrespectful, but I'm glad to have this resolved.  I wonder if the limit also applies to the V1.

[Chronon]

The v1 has different hardware, so I wouldn't expect so.