Idea to improve fingerprint sensor experience on X10 III

Design
#1

TL:DR Idea for improvement:

I propose a slight change on how to speed up screen unlock, and possibly improve battery life?
I love the behavior of my Xperia XZ1 Compact on Android, which has the same sensor-over-clicky-button setup as the 10 III.
Currently 10 III on SFOS will show the lock screen when you press the power button OR your fingerprint on the sensor even without pressing it. So the fingerprint sensor is always active, and I don’t get why, as we have a physical button already.
Then even if it already detecter your fingerprint you need to take your finger off the sensor, and put it there again, wait half of a second to read it, and then it will unlock.
Meanwhile on Android with my XZ1 C it will show lockscreen only if you press the button, so the sensor can remain inactive - possible battery life improvement?
And then it immediately starts scanning your finger, which means if you don’t take it off the sensor it will unlock the phone in half a second. So it is much faster than on SFOS. A win-win in my book
Sensor on SFOS is actually really fast, but because I need to wait till I see lockscreen, then raise the finger and lower it, it seems much slower than on Android

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[10 III] Fingerprint sensor stops working after screen gets turned on, but before unlocking the phone
#2

Not always. It is not active when the device is unlocked and the screen is on. I’d say that it is actually only active either when the display is off, or when the lock screen or security code screen is shown. Or maybe in some other case as well. But definitely not always.

There are LED patterns (disabled by default, can be enabled using mcetool) for the fingerprint sensor activity: PatternScanningFingerprint (the name is misleading because it actually shows when the sensor is active) and PatternFingerprintAcquired (which shows when the sensor is reading a fingerprint - either a recognized or unrecognized one). You can use them to monitor its activity.

I’ve got the latter pattern enabled - it shortly blinks green LED when the sensor is reading my fingerprint. I enabled it because sometimes it takes several attempts for the sensor to react and thanks to that LED at least I can know if it is because the sensor didn’t activate (in such case there’s no LED indication) or if it doesn’t recognize my finger (which means that I should put it at a different angle).

3 Likes
#3

Thank you, it is awesome there is an indicator if the fingerprint sensor is activated or not!
So even if the fingerprint sensor doesn’t work with disabled screen, there is still some degree of touch sensitivity. And I don’t think that is necessary, more of a leftover from X10 times when the button wasn’t clicky.
Also I really think the touch sensor should activate immediately after you turn the screen on, not wait for you to lift the finger off the sensor.

#4

Fingerprint doesn’t work on my 10 III. ‘Automatic lock not in use’, when tapping on 5 minutes I have to type the code. That menu has no way to confirm the code save tapping on the x below.This always brings me back to the initial locking menu: ‘automatic lock not in use’. There it is possible to install a fingerprint, but this does not work. What do I wrong?

#5

Maybe you can solve the problem via “Settings / Security / Device Lock”?

2 Likes
#6

@JacekJagosz
Wouldn’t the even better solution be to have unlock happen on first touch (as frequently requested)?
My 10 III has excellent battery life, so i can’t imagine the fingerprint sensor taking all that much energy. But a first touch unlock, even if achieved the way you suggest would be an improvement.
The question is if it is just a detour on the way to the proper one…

@Kea
I think you are off-topic (your post doesn’t obviously have anything to do with what @JacekJagosz suggests). Typing the code for confirming security-related settings is very much intended functionality. And this works just fine for me (remember that the code is at least 5 digits).

#7

It’s actally on the contrary: it works when the screen is disabled, waiting for your fingerprint. It deactivates when the screen turns on, except for the unlock code screen where fingerprint can be used instead of typing the code. And even when the display is off, it doesn’t seem to be working “always” but rather with some on/off frequency, as it happens (which enabling the aforementioned PatternFingerprintAcquired helps to monitor) that sometimes there is no sensor response when you place your finger over it and it takes a few attempts for it to react. So maybe it is controlled by some timer.

It would be good to know how much current does such a fingerprint sensor draw. If it is in the microamperes range then I wouldn’t bother to further restrict its activity. I actually prefer to use the sensor instead of clicking the power button because it prevents that button’s wear. Especially that (at least that’s the feeling I get) the power button of the 10 III feels very fragile.

IMO, already now the power saving measures applied to button click monitoring are a bit of overkilll. On the XA2 the camera button stops being monitored when the device goes to sleep. So its quick access to Camera functionality is only usable when either the display is on, or shortly after that. The same applies to Volume buttons - if there is no media playback and the device goes to sleep, they don’t work anymore.

On all my past phones, e.g. the BB10 Passport, all buttons were active all the time and I wouldn’t say that it could have had any measurable impact on battery life. Saving some microamperes by disabling all buttons (except for Power button) is simply an overkill. Especially if at the same time, as @miau reported in another thread, the 10 III never slows down below ~1.2 GHz in idle/sleep, resulting in 50mAh power consumption when not in use. How much would it be drawing if the buttons stayed active and read in sleep mode with a frequency of say 1 Hz? I seriously doubt it would be even measurable.

#8

That’s it, thank you Attah: 5-digit instead of 4. Stupid of me. Now I get an unlocking menu with code and I can choose between fingerprint and code.

#9

Did that several times. I didn’t know that the code had to be 5 instead of 4 digits. It always worked with 4, but now not anymore. Problem solved.

#10

I agree with @attah and @wetab73, the sensor can stay active while the screen is off, I don’t mind.
The most importand thing to me is that no matter how screen gets turned on, by button or the sensor, the sensor needs to keep scanning and unlock it once it detects fingerprint.
I just pointed out that it is active with screen off, I know that lead to power draw in early X10 days, as well as there is a topic of people complaining of high power draw with the 10 III. But that is a very minor thing, it can be igbored

1 Like
#11

IIRC, there’s another low-power mode of the fingerprint sensor, which recognizes when a finger has been placed on it, but doesn’t recognize it. That’s what’s active when the screen is off, and why that first touch can’t unlock the device. Having the sensor fully active all the time would not be fun for your battery.

#12

Then I wish it could immediately go into full power scanning mode, not having you to lift your finger

#13

I think it does, and that’s just how it works.

#14

There are LED patterns (disabled by default, can be enabled using mcetool) for the fingerprint sensor activity: PatternScanningFingerprint (the name is misleading because it actually shows when the sensor is active) and PatternFingerprintAcquired (which shows when the sensor is reading a fingerprint - either a recognized or unrecognized one). You can use them to monitor its activity.

I’ve got the latter pattern enabled - it shortly blinks green LED when the sensor is reading my fingerprint.

How did you enable “PatternFingerprintAcquired”? I cannot find any option for that with mcetool.

#15

mcetool --enable-led-pattern=PatternFingerprintAcquired

Then to check if it is enabled:

mcetool --show-led-patterns

3 Likes
#16

Doesn’t in android the same sensor work exactly like that and it’s ok there?.

#17

Nah, my brother has an xperia 10 iii with android and the sensor also doesn’t work reliably there.
edit: oh you mean the battery consumption. About that i don’t know, he can go about two to three days without charging, if he doesn’t use navigation for example

#18

@Blumenkraft, and after you enable that pattern, you can customize it in /etc/mce/20hybris-led.ini, e.g. by adding

PatternFingerprintAcquired=1;5;0;0;0;007b00

for a dark green short blink when the sensor is reading a fingerprint. All options you can use are clearly described in that file’s header.

2 Likes
#19

By doing what you said I managed to find something interesting, particularly with mcetool --enable-led-pattern=PatternScanningFingerprint
Sometimes after turning on the screen it keeps scanning and then it can immediately recognise fingerprint. But sometimes it stops scanning for like 2 seconds, and this is super annoying.
Up to this point I thought it simply can’t recognise my fingerprint, but it turns out is actually isn’t scanning at all!
This seems like a bug, that maybe can be fixed.
Edit: I tried to catch it on video and now can’t replicate it… Could someone confirm if it happens for them too? That the diode singaling scanning turns off for a second?

1 Like
Disable LED notification if Do Not Disturb is enabled
#20

Same thing sometimes also happens when the screen is off. It takes several attempts (or simply waiting some time) for the sensor to “wake up” and start working again…

1 Like