Near field (proximity) sensor reacts slowly/hangs up calls

I have some information that may interest all who have experienced this issue.

I’ve been testing out this thing quite a lot lately because, while when the thread was started I made a quick try and observed no delay or particular issue, I have since then, on occasions, noticed how unresponsive the sensor can indeed be.

I don’t know how the sensor works, but I suppose it is a light sensor of some kind, probably the same used by the automatic brightness utility.

Supposing my understanding is correct, I used my finger to block light from it while calling (I give the the sensor is that translucent thingy that can be seen at the opposite side of the front camera).

The switching on and off of the screen is consistently instantaneous with the finger, but when I take the phone to my ear, not so much.

What is the difference?

Well, not the angle of the phone, because I tried to block the sensor with the finger while standing, while lying on bed and in pretty much any position, and it always worked.

I though that stunning or feeble lights in the surroundings could be the culprit for the inconsistent behavior but my tests with the finger hovering the sensor always produced successful results regardless of whether I was in broad daylight or pitch dark, under the light of powerful lamp or a candle.

Then one day when the call was getting too long and I wanted to switch to the headset for comfort, I had to brush my hair away from my ear (I’m long overdue for a good grooming! :smiley: ) to put the earplug in, and while I was doing so, from the corner of my eye I saw the screen turn off instantly as the ear was free from my hair and it occurred to me the hair could be the problem.

I have tried then all sorts of positions and when I have hair between the phone and the ear, the sensor is faulty.
My hair right now is just about as long as the lower part of the ear, so depending on the wind or how I scratch my head, the ear may be anything from entirely covered to completely free from hair.
I suppose the general fuzziness around the ear is confusing the sensor.

So, in conclusion, to all those who have experienced this issue: how is your hair? :smiley:

Seriously though, can you try to experiment with the finger over the sensor in different light conditions and then repeat with or without hair over the ear, hats, hoodies and whatnot?

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I tried what you were explaining here on a longer call yesterday. By opposite of the front camera, do you mean on the left side of the speakers? Like here in this pic:

(original photo source: Fairphone flickr album)

Cause I tried holding my finger over there multiple times but nothing happened?

Heh, I’ll have you know I have very short hair. The problem I have isn’t with the display not turning off but it not turning back on (quickly).

The sensor is in exactly the position of the Picture but notice that it is only Active while making a call!

I think van has something here. First, the sensor is however NOT a light sensor, it is a near field sensor that can detect the pressence of your head. It detects objects that is conductive and your finger is that. Try a piece of metal.

I have been making calls with a cap (winter or at least autumn is coming) thus having a small distance to the sensor. That can explain the problem I have. Maybe the sensor it not enough sensitive. Worth having a closer look into.

I did hover my finger over exactly that spot multiple times (while making a call), with varying distances. It never resulted in my display turning off.
I’ll try again on my next call though. (not making a lot of calls)

Oh, I have the same problem I now realise! (My hair is short though). I have my first smartphone ever and thought it was something I had to master. My problem is in the screen staying black and in the beginning I just pushed some buttons to get it back to life, which took me out of the dial screen so I never knew how to hang up and answer phones would record my aimless attempts.

Hi, I had the same problem, or more, my wife had.
I have never had problems makeing calls but when my wife used the phone, many time the call would be interrupted whuthout she doing anything. At least she thought. I have little hair and no hair covering my ear. My wife has a lot and when I asked her to keep it clear from her ear when using the phone and now her calls are not dropped anymore!

Just to say I too can clearly notice a quite annoying lag at the end of a call, waiting in front of the black screen before the red hangup button condescends to appear (along with the rest)…

[quote=“Kris_S, post:7, topic:1117”]
I tried what you were explaining here on a longer call yesterday. By opposite of the front camera, do you mean on the left side of the speakers? Like here in this pic:

Cause I tried holding my finger over there multiple times but nothing happened?[/quote]
Hi Kris, yes, I meant that spot.

As for your tests, did you by any chance use a headset when trying with the finger over the sensor?

Oh actually I was meaning both turning on and off.
I noticed in my tests that the responsiveness in both switching off while moving he phone to the ear and turning back on when moving the phone away, increased as much as my ear was free from hair obstruction.

To me the results are pretty consistent.

I had a hunch it could be something like that.:wink:

I assumed though that the light sensor (that must be thereby somewhere) could be at least “in the mix”.

Anyway, in my tests I tried with a very thin cotton hat (a little thicker than a t-shirt) and it worked just fine, as long as under it my hair was tucked behind the ear.
Haven’t tried with a thicker winter hat though, I definitely will.

That’s interesting, it kinda confirms my suspicion, although a lot more tests would be needed to give it some relevance.

I didn’t use a headset, just my phone. And I haven’t tried this again, will report back here as soon as I get the chance!
(Also I have plenty of hair so I’ll try that, too.)

There’s no need to actually make a phone call for those tests. There are apps available that show the output of the sensors: the near field detector switches from ‘0’ to ‘1’ and vice versa on a hovering object close to the upper border of the screen.
Actually you can determine the location of the sensor quite exact this way.

This happens to me as well, a lot of phone calls are being hung up. It’s really hard getting my hair out of the way so it’s really annoying. Is this just something I have to live with or is it software-realted?

I can of course not know how the software is working but there must at least be two parameter that can be changed in software:

  1. The threshhold of when the sensor should activate. It can be a more advanced method but something like this is still there.
  2. The update speed of the sensor.

If you have a clear repeatable problem with this I suggest that you put in a fault report to the Fairphone team so they can look inte it and maybe fine tune the settings of the sensor. As Rob in the previous post said there are apps that can be used to test the sensor. That could be interesting if you tried. For me this is the single really problem I have with the Fairphone and that I Think could be a reason not to buy it.

Yeah, I’ll do that. Do you know if it’s connected to the exposure settings of the front camera? As soon as the conditions are slightly dark it will freak out…

The same problem: most of my calls get terminated after 5 seconds or so. Indeed, it seems to depend on the way I hold the phone to my ear, but I haven’t had it long enough to figure out the “correct” way. Anyway, as it’s never happened to me with my previous smartphone, I’d assume I’m not holding it in any weird way and the problem lies with the phone…
I find it very annoying.
I have the new FP1 with 1.6

Do you have long and curly hair? :slight_smile:

It’s not. The proximity sensor is a separate sensor that doesn’t work by detecting (visible) light like a camera does. Read more about proximity sensors here:

No :slight_smile: My hair is short(ish)

I have been in touch with the support team regarding my problem with interrupted calls and they adviced me to try this app
I installed it yesterday and I hope it will solve my problem.

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same problem here with additional issues:
when I use my right ear, things go well (screen goes dark when I put it to my ear, no extraneous actions)
when I use my left ear, things go crazy: after a short phonecall I find that the system brightness has been changed, a new calendar entry has been created, and various other actions have been performed.
Plus, with either ear, the screen stays black for anywhere from 1-30 seconds. Sometimes I have to press the power button, then enter my passcode in order to hang up or enter info into a touch tone service.
So clearly the sensor is not working correctly, and not only that, but it seems to prefer my right ear. I have piercings on my right ear that make it inconvenient to use that ear for phone calls. Never had such issues with my old iPhones (3G and 3GS)- for those if the screen stayed dark (rare), a little shake would wake it up instantly.
PS I have long hair, but it’s usually tied back or tucked behind my ears.