[APP] AMOLED PWMfree

[Wootever]

Summary:

• A simple application that uses a transparent overlay to dim the device brightness, effectively removing PWM.
• Download PWMfree

More Information:

• Why PWM is such a headache
• Brief explanation about PWM

Default brightness control:

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PWMfree brightness control:

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[NisseGurra]

Thanks, runs on my S9 on AOSP 8.1. Affects auto-brightness a bit but seems to work as intended. Great work!

 

[GuestK00195]

Wrong section man

 

[JohnnyEighty]

Can someone explain to me what this app on s9 does?

 

[amakuramio]

Its suspicious

 

[Wootever]

@amakuramio
Not sure why the installation is prevented.
The application itself just creates an accessibility overlay and changes the permission for /sys/class/backlight/panel/brightness to prevent access from liblights.

Edit:
Seems like this is the common behaviour for non-playstore apps: disable Google Play Protect

 

[vratnik]

The brightness does not change while sliding the slider, only after releasing the slider. Please fix, thx.

 

[VictoSab]

Can this work on other models (like my Galaxy A3 2017 AMOLED) ?

 

[Wootever]

The brightness does not change while sliding the slider, only after releasing the slider. Please fix, thx.

Unfortunately not possible.

Can this work on other models (like my Galaxy A3 2017 AMOLED) ?

The overlay itself should work on every device, only the brightness slider override that requires root is device dependent.
But this isn't particularly well-working, i will probably ditch this override and just add a widget slider so it can be used without root.

 

[qb74]

So is this root only? Cause I saw my screen change brightness immediately after turning accessibility access on, and I'm not rooted, stock rom.

 

[Wootever]

@qb74
Root permission is used to prevent liblights (android system brightness handler) from accessing the kernel brightness path (/sys/class/backlight/panel/brightness).
The brightness slider on the notification bar then only modifies the transparency of the accessibility overlay, not the display (kernel) brightness.

Without root permission it controls both the overlay and kernel brightness, but this prevents the pwmfree usage as the kernel brightness needs to be at 100% to avoid pwm dimming.

 

[parser]

Trying out on s8+. But weird thing is, when enabled, if you lower the brightness to 0% the screen becomes completely dark. It should not happen like this, I presume. The app has root access too.

 

[Wootever]

@parser
The lights service might be different on the S8 and is not correctly halted by the application.

Here is a first version that works without root and only relies on the accessibility service: (link in the original post)
It locks the device brightness at 100% and uses it's own slider to control it.

 

[qb74]

@parser
The lights service might be different on the S8 and is not correctly halted by the application.

Here is a first version that works without root and only relies on the accessibility service: pwmfree.apk
It locks the device brightness at 100% and uses it's own slider to control it.

So this version works with non-root? Great! Why does the brightness need to be 100%? From the looks of your graph, all brightness levels seem more consistent?

 

[parser]

@parser
The lights service might be different on the S8 and is not correctly halted by the application.

Here is a first version that works without root and only relies on the accessibility service: pwmfree.apk
It locks the device brightness at 100% and uses it's own slider to control it.

Hmm, well than I hope you make this wonderful app s8/+ compatible too

Thanks for your work mate. Would love to use it :good:

 

[Wootever]

So this version works with non-root? Great! Why does the brightness need to be 100%? From the looks of your graph, all brightness levels seem more consistent?

Only the device (kernel) brightness needs to be set at 100%, at this stage the amoled panel only uses a short 59hz vsync signal (this is the small amplitude on the graph).
Anything below ~95% uses the amoled typical 240hz pwm dimming.
The pwmfree overlay now dims the full kernel brightness by decreasing it's transparency, this is somehow similar to lcd contrast dimming.
@parser
The new version should work on all amoled devices, although the widget type brightness slider is a bit less comfortable than the android system one.

 

[parser]

Only the device (kernel) brightness needs to be set at 100%, at this stage the amoled panel only uses a short 59hz vsync signal (this is the small amplitude on the graph).
Anything below ~95% uses the amoled typical 240hz pwm dimming.
The pwmfree overlay now dims the full kernel brightness by decreasing it's transparency, this is somehow similar to lcd contrast dimming.

@parser
The new version should work on all amoled devices, although the widget type brightness slider is a bit less comfortable than the android system one.

Trying it atm, the only down side is, as u said, adjusting the brightness by hand. If I am in a game and need brighter screen, have to go desktop and adjust it :/

Would it have an effect on battery efficiency too?

 

[Wootever]

@parser
The overlay is managed by SurfaceFlinger and shouldn't cause any impact. The amoled panel seems to work identical with the contrast dimming and i would guess the battery usage is similar, but i can't tell for sure yet.

As for the brightness slider, i think this can be placed on the notification bar instead, which should increase the usability.

 

[vrveee]

Wootever, you're BEST!

P.S. I sold my Note 8

 

[kimush]

I installed it but it won't run, s7 stock rooted.