# CM7 AutoBacklight Settings - customize your phone backlight settings



## Redflea

Note: This is not a bug thread, if you have general backlight issues, post those in the thread Metickone refers to below. Keep this thread for talking about custom auto backlight settings.

So I've been playing with the CM7 Automatic Backlight settings in the CM Settings menu on my D2. I'm a beginner w/this, so feel free to correct/expand on my comments below if you're interested in this as well...I'm here to learn.









So...as far as I can tell from some limited reading and experimenting this evening...

The Automatic Backlight settings (CyanogenMod settings>Display>Automatic Backlight) allow you to customize how your phone reacts to changes in ambient light measured by the phone. You can control how many light level ranges you want to monitor, and how bright you want the screen, keys, and keyboard buttons to be at each range. Of course you have to enable Automatic Backlight in the normal Android settings first (Display>Brightness).

It looks like this below (this is screen shot of the current setup I'm using). At the top you can see the current sensor readings that the phone is registering, and the screen and button settings.

In table in the rest of the screen, the first two columns in each row represent individual light level ranges (lower numbers = less light, higher numbers = brighter light), and the last three columns represent the brightness setting that will be applied to your screen, haptic buttons, and physical keyboard when that range of light is measured by the phone's sensor. Phones w/out physical keyboards lack that third column, obviously.

The range is 0 (off) to 255, but I read a post or two in my searches noting that setting the screen value to 255 caused issues, so I'm maxing at 254 to be safe (may not actually be an issue, but just in case...) The last row of my settings is cut off in the screenshot - it is 3000 to infinity.










The default Automatic Brightness settings in the CM Display settings for the CM4D2 builds are below:










As you can tell, I've been experimenting, and have added levels and changed brightness settings across the range of levels. You really have pretty much complete flexibility to design whatever backlighting plan you want.

In googling around on this I've found a number of different approaches and preferences, and it really is something that is very subjective - enough light for one person at a particular ambient light level is too much for another, and vice versa.

To enable custom levels you have to select CyanogenMod settings>Display>Automatic Brightness>Use Custom, and then select Edit other levels... to edit the levels and brightness settings. Also select "Allow light decrease to allow brightness to reduce when ambient light is reduced.

You can use the "Sensor (Filtered/Raw)" readings are real-time readings you can use to view what the phone's light sensor is current reading. When on the custom settings screen (and this may not be enabled until you add some custom settings, not sure) the you can use the sensor to see how the light levels around you are measured by the phone.

There are a number of other settings, including applying a moving average filter to light sensor data so that autobrightness doesn't keep jerking your light levels around (and you can set the window length as well). You can also set the light change threshold which resets your filter and how frequently you want to sample the ambient light level. Just a bunch of cool options, in techi-speak.










My other settings:

Window length: 10s
Reset Threshold: 400 lux
Sample interval: 1s
Allow light decrease: Checked
Decrease hysteresis: 50% (default - not sure what this does...)

Not necessarily recommending my settings, I've only played with them at home, really want to have a nice sunny day outside to see how it manages going from indoor to to outdoors, but here at home I've experimented going from dark to well lit rooms and the screen brightens up nicely and dims appropriately.

So if you're interested, let me know what I'm missing, have misunderstood, etc. The more the merrier...

Again - if you have general autobrightness bugs/issues w/the default CM4D2 ROM setup, you can post those issues in this other autobrightness bug thread: http://rootzwiki.com/showthread.php?735-CM7-Auto-brightness


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## HerroMoto

Well I just have a quick comment. For some reason on Build 11, auto brightness was working perfectly. My screen wasn't bright and was changing and my softkey lights were always on. Every time I had to reboot my phone I did by holding power down and selecting reboot. My brightness would still work after I rebooted. For some reason I wanted to reboot but accidently clicked the 'power off' option. After I booted up my brightness went away. Every time I put my phone on sleep my soft key lights go off and will not turn on. This also causes my screen to be very bright and kill my battery. I was on build 11, I'm currently on build 12 to see if the brightness issue was resolved and it still isn't

Did anyone else have an experience like this?


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## metiCkOne

HerroMoto said:


> Well I just have a quick comment. For some reason on Build 11, auto brightness was working perfectly. My screen wasn't bright and was changing and my softkey lights were always on. Every time I had to reboot my phone I did by holding power down and selecting reboot. My brightness would still work after I rebooted. For some reason I wanted to reboot but accidently clicked the 'power off' option. After I booted up my brightness went away. Every time I put my phone on sleep my soft key lights go off and will not turn on. This also causes my screen to be very bright and kill my battery. I was on build 11, I'm currently on build 12 to see if the brightness issue was resolved and it still isn't
> 
> Did anyone else have an experience like this?


All I can tell you is to reinstall your rom and dont use tibu this time.

If that shill doesnt fix your problem.. go here and leave a comment so i can tally you guys up.

http://rootzwiki.com/showthread.php?735-CM7-Auto-brightness#post11854


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## Redflea

Lets keep this thread about the cm4d2 auto backlight settings, not backlight issues our bugs, there are other threads for that, as Medicine notes.


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## poontab

Doesn't the light sensor only recognize a defined range?


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## Redflea

Not sure if I know exactly what you mean, but my light sensor has registered from very low numbers up into the thousands, so mine seems to work and register quite a wide range...what I don't know is the unit of measurement (lux? lumens?).

I've noticed a couple interesting things since applying these settings:

1. Screen gets very bright in direct sunlight now, brighter than it did w/the default CM4D2 ROM settings, much more readable.

2. When turning on the screen, the screen will fluctuate briefly (dim down and then up again) and then choose the correct brightness...kinda cool looking and works very well.

Other settings I have selected (all add this to the OP as well):

Window length: 10s
Reset Threshold: 400 lux
Sample interval: 1s
Allow light decrease: Checked
Decrease hysteresis: 50% (default - not sure what this does...)

I also saw some posts in my research that if you make a number of changes to the profile in the custom screen in a row (e.g., change values, save/load them, change, save load) the autobrightness may stop working temporarily or get funky. I experienced that today when I was making changes, a simple reboot resolved it.


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## zibrah3ed

Awesome tutorial Redflea. Had no idea this was stowed away in CM settings and it worked. Finally was able to set the capacitive button backlights to always off thank you.


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## Redflea

Glad it was useful, Zibrah3ed, I was pleasantly surprised to find such a high level of control over this in settings, but documentation was hard to find.


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## simon_lefisch

finally read thru and messed with some settings. thanks for figuring out what these settings do. i would like to say (and maybe its different for other people) that when it comes to the keyboard/buttons settings, i did notice much light increase when set at 1 compared to 200. in fact i didnt see any difference in light when going in increments of 5 so i set my keyboard/buttons to 5 until it gets bright enough for no lighting. just fyi.....


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## jonbink16

even with these setting the backlight for the keyboard and soft keys don't work. :angry: The top part of the screenshot is not the same and i don't know if there is a way to change that..


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## nailbomb3

Are you still running essentially these same settings brother?


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## NyNe

Sorry to revive this, but I wanted to say thanks, your settings are a great improvement over the defaults provided for my device (sgh-i777 att galaxy s ii) and your write up was handy to read and easy to understand (not a lot of good explanations out there about this)


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## Redflea

NyNe said:


> Sorry to revive this, but I wanted to say thanks, your settings are a great improvement over the defaults provided for my device (sgh-i777 att galaxy s ii) and your write up was handy to read and easy to understand (not a lot of good explanations out there about this)


Glad it helped!

Sent from my HP Touchpad running ICS


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