Develop Bugs

Need more control over the backlight

Is there a way to tweak the behaviour of the auto-brightness backlight? At the moment it correctly goes up to full brightness in sunlight, but it doesn't go as dim as I would like under artificial light. At home, after dark, under electric light, I can manually turn the screen brightness down to the minimum level, and it's still bright enough - the auto setting is much brighter than that(although clearly much dimmer than it is in sunlight, so it is doing something).
Can this be tweaked? Failing that, is there an easier way to control the brightness manually - something I can keep running all the time, and which doesn't require the stylus to change the setting?

Try GLight
http://www.ageye.de/index.php?s=glight/about

JustBored said:
Try GLight
http://www.ageye.de/index.php?s=glight/about
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Thanks, I'll give that a try.

I find Lumos to be more stable and reliable
http://forum.xda-developers.com/showthread.php?t=450318

Ok I havn't tried either of them before but I just installed G-Light.
After a bit of config. it's ok. You need to give each backlight number a wider setting.
Otherwise it'll just flip back and forward in brightness.

So far G-Light is proving rather dissapointing. The phone's built-in "Auto" setting works well, apart from the fact that the brightness doesn't go low enough in dim light - in particular, it manages to choose a good level and then stick to it. G-Light, by contrast, keeps changing the brightness up and down all the time.
I think the notion of having absolute brightness bands may be the wrong way to go. You really want a set-up where the threshold values are in different places depending on whether the light is getting brighter or dimmer. So, as the light fades, you cross a threshold and dim the screen - but when the light goes slightly back up over that threshold, you don't brighten the screen again until it gets significantly higher than that. That way, regardless of the light level, the screen brightness will be steady unless the ambient light level is changing a lot. If you use single threshold values then whenever the ambient light happens to be very close to a threshold value you will always get the brightness going constantly up and down.
Edit: some of the things Lumos does (like averaging across multiple readings) sound hopeful, though. I'll give that a try.

Shasarak said:
So far G-Light is proving rather dissapointing. The phone's built-in "Auto" setting works well, apart from the fact that the brightness doesn't go low enough in dim light - in particular, it manages to choose a good level and then stick to it. G-Light, by contrast, keeps changing the brightness up and down all the time.
I think the notion of having absolute brightness bands may be the wrong way to go. You really want a set-up where the threshold values are in different places depending on whether the light is getting brighter or dimmer. So, as the light fades, you cross a threshold and dim the screen - but when the light goes slightly back up over that threshold, you don't brighten the screen again until it gets significantly higher than that. That way, regardless of the light level, the screen brightness will be steady unless the ambient light level is changing a lot. If you use single threshold values then whenever the ambient light happens to be very close to a threshold value you will always get the brightness going constantly up and down.
Edit: some of the things Lumos does (like averaging across multiple readings) sound hopeful, though. I'll give that a try.
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Let me know how Lumos is.

Yes as I said earlier you need to widen those settings.
For now I have 5 set to 0-81
6 set to 82-200
8 set to 201-600
10 set to 601-1000
All the rest are disabled by setting the values to -1 to -1

HeavyComponent said:
Let me know how Lumos is.
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Lumos is also proving dissapointing. It's partly the fault of the hardware - the sensor seems to read 0 even in surprisingly bright light, so the app has no way of telling whether you're at a light level where backlight 1 is appropriate or a light level where backlight 3 is appropriate - both read 0 on the sensor. (This is probably why the default auto option doesn't go below 3 in the first place).
As for Lumos, the author needs to realise that perception of brightness is actually based on an exponential curve. That means that all of the values between level 1 and level 5 are somewhere between 0 and 80 sensor reading. The graph interface is useless for editing custom values with that level of precision - it's trying to squeeze over 2000 values into less than 800 pixels of screen space, and the pixels are tiny! I think you can edit the values directly in the settings.txt file, but that's fiddly - there should be spinboxes, really (as with G-Light).
In any case, you don't want to be editing the values directly! What you want to be doing is taking the phone out of your pocket, looking at it, and thinking "hmm, the screen is too bright at the moment" then adjusting the brightness to whatever level is comfortable for the current ambient light level. The programme should then interpolate the curve that you want, and progressively refine it each time you decide it isn't quite right and tweak the brightness.

I haven't tried to Lumos program yet, but I've been using Glight for a few days. At first I had some issues with it but then I realized that you have to turn the auto light adjustment off in settings first. If not, they'll both be fighting against one another.
Also, you have to set your thresholds pretty carefully as has been already stated. Mine is set to go bright only in bright outside and lowest in a dark room with no light at all.
1 0 to 5
3 10 to 799
8 800 to 2500
I've got mine set low for better battery life and the screen is always readable to me no matter what anyway.
Also, if you're using a the snap on rubber protector (I got a T-Mobile one) it will interfere with the light sensor. I just got one and the lighting is all over the place now. Time to order a full body screen protector.

GLight doesn't seem to work for me. keeps crashing, and the settings don't seem to save at all.
I don't want a sliding scale that Lumos has since i don't think the light sensor is all that accurate (sometimes thinks it's too bright and sometimes thinks its too dark). would rather just have a few settings (pitch black setting, super bright setting, and in the middle) as shawndh suggested.
i have the verizon tp2 - not sure if this might be causing some of the glight probs.

[Q] Ambient Light Sensor Limitations??

I haven't been able to find an answer so far to this, so here goes.
I've played around extensively with the Auto-Brightness settings, tweaking to my desires. However, I'm still having problems in lower light conditions. Not a dark environment, mind you, but simply indoors without a light shining directly on the light sensor.
From what I can tell by watching the Sensor readings (under Edit Light sensor levels...), the sensor jumps from a low limit reading of 10 all the way up to 160 without any steps in between. Above that and the level jumps are less of an issue (and in fact, there are more steps). But because of the 10/160 jump, I end up with an "all or nothing" type situation. I can either have a comfortable, dimmer brightness level when it's dark, but have a screen that's too dim under normal conditions; or I can have it comfortably bright under normal use, but overly so in darker situations.
My question, after all of that, is whether this is a hardware limitation or something that could be modified in the code for the sensor?
I am willing to put in some work on this issue if someone can provide some direction on what I need to look at.
Thanks

Do you have the filter option enabled?

nukedukem said:
Do you have the filter option enabled?
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I do. That shouldn't affect the raw values, though, only the filtered ones to the left of the raw values.

kevinbear said:
I haven't been able to find an answer so far to this, so here goes.
I've played around extensively with the Auto-Brightness settings, tweaking to my desires. However, I'm still having problems in lower light conditions. Not a dark environment, mind you, but simply indoors without a light shining directly on the light sensor.
From what I can tell by watching the Sensor readings (under Edit Light sensor levels...), the sensor jumps from a low limit reading of 10 all the way up to 160 without any steps in between. Above that and the level jumps are less of an issue (and in fact, there are more steps). But because of the 10/160 jump, I end up with an "all or nothing" type situation. I can either have a comfortable, dimmer brightness level when it's dark, but have a screen that's too dim under normal conditions; or I can have it comfortably bright under normal use, but overly so in darker situations.
My question, after all of that, is whether this is a hardware limitation or something that could be modified in the code for the sensor?
I am willing to put in some work on this issue if someone can provide some direction on what I need to look at.
Thanks
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Click to collapse
Yeah, I had this same problem. In general, I just found things were too bright. I've had good luck with these settings:
Sensor Filter: Enabled
Window Length: 20s
Reset Threshold: 1000 lux (any lower and it seems to get triggered too much).
Sample Interval: 2s (Since it's on a 20 second window length, I didn't see the need for super frequent sensor reading)
Use Custom Light Levels: Enabled
Screen Dim Level: 20 (default)
Allow Light Decrease: Enabled
Decrease Hysteresis: 40%
My light levels:
Lo-Up Screen Buttons
0-10 40 255
11-40 50 255
41-90 60 255
91-160 75 255
151-225 85 0
226-320 95 0
321-640 110 0
641-1280 120 0
1281-2600 140 0
2601-3099 160 0
3100-4099 180 0
4100-5099 200 0
5100-6099 220 0
6100-7099 230 0
7100-inf 255 0

Thanks for the response! I will try your settings and see how it works for me.
So were you getting similar raw sensor readings, too?

Retroillumination level

I am using miui 2.3.7 from months and I notice that in display settings, sensor (filtred/raw) is usually 10 in low light conditions. So if I set for example 50 for level retroillumination, I had the same illumination of the screen in a totally dark room and in twilight light in outside. This is annoying because I want to set lower level for the first situation and higher for the second. A solution can be to use manual settings but if someone have an idea on how resolve the automatic levels I will be glad. Thanks

[Q] Adjusting the LED flashlight brightness

The brightness of the LED flashlight can be changed by modifying the value in /sys/class/leds/flashlight/brightness (or alternatively /sys/devices/platform/flashlight.0/leds/flashlight/brightness).
I've managed to vary the brightness, however there seem to be only 3 settings which stay (0, 64 and 128).
The max_brightness file is set to 255, which implies the brightness could be doubled (not that it necessarily should) - however setting it to that will increase the brightness to "very bright" and then switch off (presumably to "0") shortly after. I also tried 192, and the same things happens (I'm not sure if the brightness is set to "192" or "255" for that case before turning off).
This implies the levels are being overwritten shortly after to "0", "64" or "128" by the device/system.
Kevin (the author of TeslaCoil) writes saying that HTC devices only support 3 brightness levels (can't post outside links as under 10 posts):
ht[REMOVE_ME]tp://stackoverflow.com/questions/5970188/can-i-change-the-led-intensity-of-an-android-device
Is there any way to bypass these preset levels and have the LED at e.g. 255 or any intermediate level in the range [0,255]? I'm making the assumption that the LED's brightness can be comfortably varied without damaging it (please say if you know otherwise ).
Cheers, Arite.

Not sure if this will help, but there is a camera apk in the oxygen rom that has a high brightness mode. Might be worth having a look at that to see what level it's setting it to?

Thanks - I'll check it out. The default/normal brightness is actually 64 (I thought it was 128), and then the can be raised to 128. The level is forgotten after though (goes back to 64). Will have a look at the Oxygen camera.
Cheers, Arite.
Sent from my HTC Desire using xda app-developers app

Of course by camera apk, I did mean torch apk

Ah OK, cheers .
Arite.
Sent from my HTC Desire using xda app-developers app

I did: cat /sys/class/leds/flashlight/brightness with the brightness on normal and then high, the results were 127 and 3.
Yes, unexpected but a brightness of 3 was much higher than that of 127. When I tried setting the brightness to 3 manually, as you experienced it automatically turns off.
I can only imagine the app either uses a loop or turns off a safety somewhere before ramping up the brightness (it does require root).
Edit: Also, the source can be found here: http://code.google.com/p/n1torch/source/checkout

I tried values of 1, 2, 3 and 4: values of 1, 2, and 4 just enable the normal "64" brightness. 3 appears to be the max brightness (same as 255) and turns off shortly after.
Interesting how "3" seems to be a special value. This, and 255 can be kept on by continuously re-setting the value - so a timed loop could be written to have it "permanently" on like langers2k said. Don't think I'll do that though as there might be a good reason it get turned off shortly after.
Anyway - I think there are only 4 possible states: off, "normal", "brighter" and "max brightness" (which turns off after something like 750ms). TBH I'm not sure a LEDs intensity can be smoothly adjust from off to max - not like an incandescent bulb. It was an interesting experiment with it anyway.
Cheers, Arite.

At what brightness auto level you keep your phone.

I used to have it at 100% now doing 50%. does it really affect battery?

Adjusting the brightness in general does affect battery life. Although I'm not sure how much adjusting the %, while still using the "Auto" feature will work out. My thought on adjusting the % (while still using Auto) is not so much about battery life, but rather to have some more customization on how bright you like the screen. Many folks will criticize that Auto brightness algorithms are often insufficient and too bright or too dark for the given situations.
If battery life is your concern, I would suggest ditching "Auto" altogether. Reason being, being on Auto constantly polls the light sensor which in itself uses some battery
I haven't experimented with this phone, in particular. But on a previous device, I found anecdotally that turning off Auto and manually having it set to 40% brightness increased the battery life by around 30-40%. Of course, you mileage will vary, and it will depend on how you use your phone and other factors; as well as what brightness level you prefer.

eduardmc said:
I used to have it at 100% now doing 50%. does it really affect battery?
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redpoint73 said:
Adjusting the brightness in general does affect battery life. Although I'm not sure how much adjusting the %, while still using the "Auto" feature will work out. My thought on adjusting the % (while still using Auto) is not so much about battery life, but rather to have some more customization on how bright you like the screen. Many folks will criticize that Auto brightness algorithms are often insufficient and too bright or too dark for the given situations.
If battery life is your concern, I would suggest ditching "Auto" altogether. Reason being, being on Auto constantly polls the light sensor which in itself uses some battery
I haven't experimented with this phone, in particular. But on a previous device, I found anecdotally that turning off Auto and manually having it set to 40% brightness increased the battery life by around 30-40%. Of course, you mileage will vary, and it will depend on how you use your phone and other factors; as well as what brightness level you prefer.
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I've always manually adjusted autobrightness and generally leave it set at around 40% and adjusting when I need to, which typically isnt a great deal each day. Very rarely go anywhere near 100% brightness. It may be worth experiementing and monitoring your battery life for auto and manual over say a week to see the results.

I was under the impression that the slider position was irrelevant if Auto was selected. So setting the slider on Auto sets the upper limit the algorithm uses?

bruce7373 said:
I was under the impression that the slider position was irrelevant if Auto was selected. So setting the slider on Auto sets the upper limit the algorithm uses?
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Your second point seems to be the case, yes.
You will notice even if "Auto" is selected, moving the slider back and forth will make the screen dimmer/brighter for the given ambient lighting condition.
On older devices, your first point was true. Selecting one would override the other. If I remember properly, manually selecting a brightness level would deselect the "Auto" feature.

My understanding has always been that the slider sets the MAX brightness the screen will go up to when set to auto. So if you put it on 50% and go outside in bright sunlight the screen will only go up to 50% which may not be enough. I set mine on 100% and that way if I am in direct sun the screen will go as high as it can and still go down as low as is needed when in a dark room. I will also say that of all the phones I have ever owned this one has the best auto brightness implementation of them all as a stock feature.

jaseman said:
My understanding has always been that the slider sets the MAX brightness the screen will go up to when set to auto. So if you put it on 50% and go outside in bright sunlight the screen will only go up to 50% which may not be enough. I set mine on 100% and that way if I am in direct sun the screen will go as high as it can and still go down as low as is needed when in a dark room. I will also say that of all the phones I have ever owned this one has the best auto brightness implementation of them all as a stock feature.
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That's what I thought but it's the opposite! From HTC website: "With the*Automatic brightness*option selected, drag the slider to set the maximum brightness level.*This sets a LIMIT on how bright the screen will be when*Automatic brightness*is selected"
Source: http://www.htc.com/us/support/htc-one-m8/howto/465124.html
This means that it will only affect the lowest brightness level, not the highest, meaning you can have it a 0% and it will always go to maximum brightness when in direct sunlight. I've tested this and can confirm it's empirically true.