Proximity sensor always on?
asked 2013-12-30 00:53:07 +0200
Is proximity sensor supposed to be always on? I can see the dimm red light coming from the LED even when my Jolla is in standby.
3 Answers
answered 2014-06-11 16:43:37 +0200
The proximity sensor is always enabled on purpose.
Having always up-to-date proximity sensor data available makes things easier in general and does not require making changes to legacy logic that assumes so.
The increased power consumption is negligible when the device is actively used. And when the display is blanked, using proximity sensor allows us to turn off double tap detection that could potentially consume much more power than what the proximity sensor does.
@tvicol: Yes, the sensor is put to a less power consuming state when the device is suspended.
answered 2014-03-20 10:36:55 +0200
If this is the case, than I expect phone to be completely locked while proximity sensor is covered. Right ? Well this is not the case. Even the proximity sensor is covered, you can unlock the phone by pressing power button. Now I understand why I got my phone unlocked while wearing in the pocket.
On other hand, while phone is locked, proximity IR led should change his frequency to a lower rate in order to save battery. Duty cycle may be adjusted as well. Take this as an electronics engineer humble opinion. ;)
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Asked: 2013-12-30 00:53:07 +0200
Seen: 4,015 times
Last updated: Jun 11 '14
AFAIK, it should always be on while the device is locked, but while it's on, that might be a bug. Unless the red light is also for the brightness sensor.
Bulder ( 2013-12-30 01:13:35 +0200 )editwhy would it be on when it's locked? what exactly is this led for or this sensor for anyway?
AL13N ( 2013-12-30 02:04:28 +0200 )editOn my Lumia 720 the LED is visible only when I press the power/unlock button or when I start camera while the phone is locked.
Edit: the LED on Lumia is visible also while making a call. So on Lumia it's only a proximity sensor IMO. Not sure about Jolla though.
pelsepupi ( 2013-12-30 02:45:42 +0200 )editOn N9 proximity sensor is always on, because it controls the 'always visible' clock on the lock screen. I don't think Jolla currently has any use for proximity sensor when the phone is locked, but I'm guessing there will in the future.
Milo ( 2013-12-30 04:10:50 +0200 )editBulder, I'd go even as far as converting that to an answer.
Milo ( 2013-12-30 14:38:35 +0200 )edit