SNS compass not accurate when vertical - Nexus S General

when the nexus s is flat /horizontal the compared seems fairly accurate. However if I point the device say due east and slowly tilt the device 90° in the vertical direction, still pointing east, the reading is off by about 15°.
This is very noticeable when I use the compass app or google sky maps. anyone else noticed this?
Sent from my Nexus S using XDA App

I have noticed the compass is terrible and noisy in general. There's supposed to be a new sensor fusion API, but as far as I can tell that is currently broken and reports NaNs...
There are many factors that could contribute to your compass being wrong, the first being that compasses are wrong! The first, Magnetic Declination is the offset between magnetic north and true north. Mine is about -8 degrees.
wikipedia.org/wiki/Magnetic_declination
The second, and probably more important factor is the Magnetic Inclination: the actual angle of the magnetic field relative to the ground. Here in Ohio, the field is mostly 60% or so vertical!
wikipedia.org/wiki/Magnetic_inclination
If the coders do not correct for the actual rotation of the sensor, then what you see is the large Z axis (coming out of the screen) become the new Y measurement, while X stays the same. Since the first trivial calculation of heading is: atan2(y,x) you can see what happens when y becomes much larger, but x stays the same.
So it all depends on if they are using the accelerometers/gyros to correct for orientation and then calculate heading or at the very least relabel axes at some point.
You can read more about what Android actually provides developers here
developer.android.com/reference/android/hardware/SensorEvent.html
But without access to the source code, I can't know what's actually causing your problem.

I have the same issue
please report this bug at here:
http://www.google.com/support/forum/p/Google+Mobile/thread?tid=37f2dd3261d20d1f&hl=en
and add a star if you have this issue as well here:
http://code.google.com/p/android/issues/detail?id=15999
check my issue video here:
http://www.youtube.com/watch?v=l-9lehX8u2U
Google please fix this!!!

Related

Maxtouch sensor input lag

Hey guys, so I tested the evo 4g, which is supposed to have the same Atmel maxtouch multitouch sensor and find that it has significant input lag (tested with multitouch visualizer) basically the dot which signifies where the input coordinates are lags about 1/2 second to 1 second behind the movements of my fingers, I was wondering if anyone with an incredible could test it on theirs and so maybe shed some light onto whether it was a software issue or a hardware issue with the maxtouch. thanks!
Dorick said:
Hey guys, so I tested the evo 4g, which is supposed to have the same Atmel maxtouch multitouch sensor and find that it has significant input lag (tested with multitouch visualizer) basically the dot which signifies where the input coordinates are lags about 1/2 second to 1 second behind the movements of my fingers, I was wondering if anyone with an incredible could test it on theirs and so maybe shed some light onto whether it was a software issue or a hardware issue with the maxtouch. thanks!
Click to expand...
Click to collapse
Individual Touch, Single Finger: Very responsive. No lag (estimate <20ms). Can successfully tap many times/second with no drop-outs.
Individual Touch, Alternating Fingers: Comfortably responsive. No lag as long as presses are distinct, as if with a single finger. If there is a slight overlap in the alternating touches, often only one point will be detected. You can see this by rapidly tapping back and forth between two fingers on the screen -- an occasional touch is missed (you have to be very fast) -- likely because the duration of the overlap does not seem long enough for a multi-touch detection (see below).
Multiple Touch: If fingers are in motion (swiping, pinching, etc.) when contact is made with the screen, then both points will be detected very quickly (estimate <150ms) and subsequently tracked very well as they continue to move. There is, for the most part, no detectable lag for me in tracking the locations of two fingers moving about. If you really go nuts moving them about the screen, then the multi-touch detection will occasionally 'stutter' for a split-second here and there, but nothing like the 1/2s to 1s you describe. If fingers are stationary when the screen is touched, not in motion, then it seems to take much longer for the multi-touch to be detected (estimate >500ms), and even then perhaps it is detecting a slight movement in one of the points. Is a tiny bit of motion perhaps required for the multi-touch detection to even work? I don't know enough about the technology to answer that one.
Overall: Excellent real-world responsiveness (apart from a separate, and conditional, grounding issue some of us have experienced). The only situation I could see someone having trouble with is if they are a lighting fast typist with the on-screen keyboard. If you type fast enough to overlap some of your key presses, than you will probably notice some missed letters here and there, and a few scattered reports seem to bear this out. I am not that fast, and I find the sensor on the Incredible to be a huge improvement over any other smart phone I have ever used.
Hope that helped. Cheers!
Thanks alot for your detailed analysis! Seems like its a software issue on the evo then I suppose.
in froyo update i think they will fix that
both of them does not have the max touch technology (you cannot use nither fingre nails nor stylus ) and it has the same matrix pattern in all htc devices screen ,so what
hoss_n2 said:
both of them does not have the max touch technology (you cannot use nither fingre nails nor stylus ) and it has the same matrix pattern in all htc devices screen ,so what
Click to expand...
Click to collapse
I realize that Atmel makes the claim that the MaxTouch sensor family works with fingernails, gloves, or a plain stylus, and that we clearly cannot use those things on the Incredible, but rest assured, we have a MaxTouch sensor all the same.
See attached cropped picture of a partially disassembled Incredible, look towards the bottom-center for a chip marked Atmel MXT224. Specifications for the MXT224 are a little different from the overall MaxTouch family description, and they do *not* include mention of support for fingernails, gloves, or plain stylus, while it does specifically reference a 'conductive' stylus.
askwhy said:
I realize that Atmel makes the claim that the MaxTouch sensor family works with fingernails, gloves, or a plain stylus, and that we clearly cannot use those things on the Incredible, but rest assured, we have a MaxTouch sensor all the same.
See attached cropped picture of a partially disassembled Incredible, look towards the bottom-center for a chip marked Atmel MXT224. Specifications for the MXT224 are a little different from the overall MaxTouch family description, and they do *not* include mention of support for fingernails, gloves, or plain stylus, while it does specifically reference a 'conductive' stylus.
Click to expand...
Click to collapse
it is written it only supports two fingres not more
wow this is really confusing, great find on the chip number, so on the specifications it mentions one touch or two touch support.
BUT it is listed under unlimited touch on this page
http://www.atmel.com/dyn/products/devices_v2.asp?family_id=701
what gives?

DVP case line up correctly?

I bought a dell venue pro and although the gap between the screen and keyboard sections seems consistent, I am noticing that the angle does not flow perfectly.
I would expect that if I swipe my finger along the angle of the case on the top and bottom that it should be smooth, however, there is a small bump where the angle seems to be inconsistent. This is hard to explain, however, hopefully those of you with the device know what I am talking about.
How is the case on yours? Does it line up perfectly? Inconsistent angle? Toughts? Thanks.
I see exactly what you mean, I think it's ok. It hasn't stopped me enjoying mine.
codeworks said:
I bought a dell venue pro and although the gap between the screen and keyboard sections seems consistent, I am noticing that the angle does not flow perfectly.
I would expect that if I swipe my finger along the angle of the case on the top and bottom that it should be smooth, however, there is a small bump where the angle seems to be inconsistent. This is hard to explain, however, hopefully those of you with the device know what I am talking about.
How is the case on yours? Does it line up perfectly? Inconsistent angle? Toughts? Thanks.
Click to expand...
Click to collapse
I've had 3 DVPs. First one I dropped, the 2nd one needed replacement and the third is perfect. the first 2 lined up perfectly. This 3rd one is slightly offset. But....the device runs perfectly and has for almost 2 months.....I'll be living with the offset !!!

Orientation OR Magnetic Sensor

Hi All
I have finished working on a compass app and I have used orientation sensor.
my question is, is it better to use magnetic sensor or orientation sensor?
What's the difference between the two? Any help or comment will be highly appreciated. Regards. Shiraz
Sent from my Desire HD using XDA App
Well, the orientation sensor will need to be calibrated to give any meaningful information on what direction it is pointing, but I think it would be more accurate, based on my experience, than the magnetic sensor. Keep in mind that "magnetic north" varies wildly depending on your place on the globe and varies locally depending on ferrous materials in the vicinity of the device.
Thanks Gene
Sent from my Desire HD using XDA App

[Q] Touch sensitivity affected by anti glare screen protector?

Does anyone know if the use of an anti glare screen protector or any screen protector for that matter would affect touch sensitivity of the Nexus 7? I'm currently using an anti glare screen protector for the Galaxy Tab (2) 10.1 which I trimmed down for temporary use with the Nexus 7 until the ones I ordered online arrive.
However, I notice that whenever I'm doing things such as rapidly scrolling through lists, the kinetic scrolling will suddenly stop every once in a while. This also occasionally happens with the notification center, where I'm in the middle of pulling down the notification bar and it acts as though my finger only pulled it down part way, which either results in the notification bar to retract back to the top of the screen or to fall open on its own without the use of my finger.
Does anyone know if using a screen protector would cause problems with touch screen sensitivity? I have qualms about returning this or exchanging it as it's the 3rd one I have gotten and it has no other problems as far as I can tell.
Tl;dr ver: Do screen protectors affect touch screen sensitivity?
Sent from my Nexus 7 using Tapatalk 2
As distance increases the capacitance effectively decreases, yes. So the thicker the material layers are between your fingertip and the underlying sensor the less responsive (or less sensitive) the sensing becomes. This correlation occurs on a logarithmic scale and most devices I've looked at spec out at about 6mm - where 6mm of material effectively inhibits sensing completely. Most phone screens that's I've been able to investigate have about 0.6mm to 0.8mm of material already. I don't know what the thickness of the typical protector sheets are but even if yours is 1mm thick (which would be very thick actually!) it shouldn't effect touch registrations by very much. A little bit yes, but I guess it wouldn't be noticeable in practice.
Of course the easy way to find out is to turn on the touch indicators if your phone/kernel support it and try it both with and without the protector in place.
One way to increase touch sensitivity with your device is to increase your iron intake. Iron tablets are cheap and good for you. Make SURE you follow any dosage instructions on the label as iron is one of those minerals which can cause problems if you over dose yourself.
Bifurcator said:
As distance increases the capacitance effectively decreases, yes. So the thicker the material layers are between your fingertip and the underlying sensor the less responsive (or less sensitive) the sensing becomes. This correlation occurs on a logarithmic scale and most devices I've looked at spec out at about 6mm - where 6mm of material effectively inhibits sensing completely. Most phone screens that's I've been able to investigate have about 0.6mm to 0.8mm of material already. I don't know what the thickness of the typical protector sheets are but even if your is 1mm thick (which would be very thick actually!) it shouldn't effect touch registrations by very much. A little bit yes, but I guess it wouldn't be noticeable in practice.
Of course the easy way to find out is to turn on the touch indicators if your phone/kernel support it and try it both with and without the protector in place.
Click to expand...
Click to collapse
That sounds like a pretty good amount of knowledge you have on screen protectors. Although, I wonder if it is also a possibility that the screen itself is flawed. I often find myself testing the touch screen with multi touch apps and I can never see any point where the screen will not register a touch. It also doesn't seem to be software based either it occurred on stock as well as CM10.
Sent from my Nexus 7 using Tapatalk 2
I of course wouldn't know if your sensor was defective or not. But the design is extremely simple and the way they work would imply that if it worked in one area of the screen it will work across the entire screen given that the relative dielectric constant is even throughout the material volume. And if it wasn't you would likely see it as thousands of micro-bubbles, cracks, or other aberrations.
Also keep in mind that temperature and humidity have affect as well.
Bifurcator said:
I of course wouldn't know if your sensor was defective or not. But the design is extremely simple and the way they work would imply that if it worked in one area of the screen it will work across the entire screen given that the relative dielectric constant is even throughout the material volume. And if it wasn't you would likely see it as thousands of micro-bubbles, cracks, or other aberrations.
Also keep in mind that temperature and humidity have affect as well.
Click to expand...
Click to collapse
Thanks for the explanations. Looks like I'll spend a few days experimenting with and without a a screen protector in order to deduct if the screen protector is at fault or if it is a defect within the product.
Sent from my Nexus 7 using Tapatalk 2
MidnightXZ said:
Thanks for the explanations. Looks like I'll spend a few days experimenting with and without a a screen protector in order to deduct if the screen protector is at fault or if it is a defect within the product.
Click to expand...
Click to collapse
NP, you're welcome. And take some iron tablets!
Bifurcator said:
NP, you're welcome. And take some iron tablets!
Click to expand...
Click to collapse
Iron tablets? Do they increase my ability to interact with a capacitive touch screen or something? xD
Sent from my Nexus 7 using Tapatalk 2
MidnightXZ said:
Iron tablets? Do they increase my ability to interact with a capacitive touch screen or something? xD
Click to expand...
Click to collapse
Yep! The difference between a person with an iron deficiency and someone with a goodly amount can be enormous. In typical variations (say a poor iron intake in the diet compounded by a blood donation or menstruation as opposed to a person eating right and supplementing) can be over two times in terms of touch sensitivity.
If there's zero iron in your blood (besides being in danger of immediate death from organ failure.. ) your touch screen will not be able to detect you at all. The iron in an individual's blood creates strings of capacitors between every epidermal surface of the body. When someone creates a capacitance by touching (or actually even moving into proximity) of the sensor's conductor it creates a capacitance (essentially coupling to ground) by adding a second capacitance (you) in parallel to the sensor's capacitance. When such a ground is introduced the charge-time (frequency) of the sensor slows way down and a "touch" is registered. This is the basic premiss (in brief!) behind Capacitive Touch Sensing (CTS). There's other things going on as well depending on the type of touch screen but almost all of them (found in cell phones) depend on this basic principal.
Fun facts aye? LOL
Bifurcator said:
Yep! The difference between a person with an iron deficiency and someone with a goodly amount can be enormous. In typical variations (say a poor iron intake in the diet compounded by a blood donation or menstruation as opposed to a person eating right and supplementing) can be over two times in terms of touch sensitivity.
If there's zero iron in your blood (besides being in danger of immediate death from organ failure.. ) your touch screen will not be able to detect you at all. The iron in an individual's blood creates strings of capacitors between every epidermal surface of the body. When someone creates a capacitance by touching (or actually even moving into proximity) of the sensor's conductor it creates a capacitance (essentially coupling to ground) by adding a second capacitance (you) in parallel to the sensor's capacitance. This is the basic premiss (in brief!) behind Capacitive Touch Sensing (CTS). There's other things going on as well depending on the type of touch screen but almost all of them (found in cell phones) depend on this basic principal.
Fun facts aye? LOL
Click to expand...
Click to collapse
Very fun indeed. xD
I had problems with 2 different screen films. One was a iPad one trimmed down to fit the other a nexus 7 one ordered online. Both seemed OK for one or two touches but lost all when I tried some games, like bad piggies and plants vs zombies. Had to take them off .
Sent from my Nexus 7 using xda app-developers app
Yeah, it certainly is possible. It sounds like the nexus 7's sensor may be a bit on the weak side just from reading here.
<shrug>
Bifurcator said:
Yeah, it certainly is possible. It sounds like the nexus 7's sensor may be a bit on the weak side just from reading here.
<shrug>
Click to expand...
Click to collapse
My first Nexus 7 had no problems with an anti glare screen protector although it did have screen lift albeit, that screen protector was designed for it. 2nd was replaced within 5 minutes if purchasing. 3rd and current one seem to have intermittent touch issues when swiping. Although I have yet to determine if the cause is the screen protector or the device itself.
Sent from my Nexus 7 using Tapatalk 2
Any progress?
I think it's almost impossible for it to be the fault of the screen protector. But there are many kinds of touch screens and if the Nexus7 just happens to be using some hybrid that needs pressure then it's certainly possible.
Think of CTS screens (almost) as proximity sensors. They can actually sense (you) from around a foot away quite easily. As the distance decreases the "signal strength" increases. If we apply an arbitrary numerical value to that signal strength it /might/ look something like:
9 inches - 0.01
8 inches - 0.02
7 inches - 0.02
6 inches - 0.03
5 inches - 0.04
4 inches - 0.05
3 inches - 0.07
2 inches - 0.10
1 inches - 0.20
0.1 inches - 1.00
0.001 inches - 2.00
0" full contact - 10.00
But typically the software algorithms which determine whether a touch event has occurred or not imply a threshold value of (again arbitrary for the sake of example), 9.00. The dielectric properties of "the" plastics of interest for protectors and screens have been thoroughly examined and established AFAIK. They do disperse the electrical force somewhat via factors such as air-space between the protector layer and the screen, whatever insulating impurities may be present in the protector material, the material's own molecular structure, and etc. The amount of electrical field dispersion or distortion that occurs through the material is a function of the materials thickness in the case of the materials commonly being used. Maybe you can imagine looking at a flashlight through murky/milky water where the closer you get the stronger the signal and the more clarity (of the source) can be distinguished. Where this "strength/clarity" begins to become a problem for software "touch" detection is usually around 5mm or 6mm (of commonly used material) between your fingertip and the sensor. If different materials are used this distance changes and can change radically. In keeping with my photovoltaic example, if the material in question could act like a tight bundle of optical fibers (only of course conducting electricity and not light) then the "protective" material could be meters thick without being detrimental to the registration of a touch event.
This is why i think it's almost impossible for it to be the fault of the protector... But everything factor's in. Body weight, blood iron content, protector material impurities, humidity (RH), temperature, skin moisture, variations in the Earth's electrical field from area to area and over time, material thickness, the software algorithm's threshold values, and so on. If they all come together in just the wrong way you could experience the touch registration intermittence you are describing - for sure. And with millions and millions of sensor screens being manufactured it could also be faulty connections there too but /that/ would be my very last guess as they really are ultra-simply constructed. If it's charging at all it should (famous last words) work equally across the entire surface area.
---------- Post added at 01:20 AM ---------- Previous post was at 12:58 AM ----------
Have a look at that poll thread tho:
http://forum.xda-developers.com/poll.php?do=showresults&pollid=9771
416 people report screen separation and almost 130 people report touch-screen malfunction.
That's pretty radical! Maybe it's time to ditch Nexus7 all together?
Bifurcator said:
Any progress?
I think it's almost impossible for it to be the fault of the screen protector. But there are many kinds of touch screens and if the Nexus7 just happens to be using some hybrid that needs pressure then it's certainly possible.
Think of CTS screens (almost) as proximity sensors. They can actually sense (you) from around a foot away quite easily. As the distance decreases the "signal strength" increases. If we apply an arbitrary numerical value to that signal strength it /might/ look something like:
9 inches - 0.01
8 inches - 0.02
7 inches - 0.02
6 inches - 0.03
5 inches - 0.04
4 inches - 0.05
3 inches - 0.07
2 inches - 0.10
1 inches - 0.20
0.1 inches - 1.00
0.001 inches - 2.00
0" full contact - 10.00
But typically the software algorithms which determine whether a touch event has occurred or not imply a threshold value of (again arbitrary for the sake of example), 9.00. The dielectric properties of "the" plastics of interest for protectors and screens have been thoroughly examined and established AFAIK. They do disperse the electrical force somewhat via factors such as air-space between the protector layer and the screen, whatever insulating impurities may be present in the protector material, the material's own molecular structure, and etc. The amount of electrical field dispersion or distortion that occurs through the material is a function of the materials thickness in the case of the materials commonly being used. Maybe you can imagine looking at a flashlight through murky/milky water where the closer you get the stronger the signal and the more clarity (of the source) can be distinguished. Where this "strength/clarity" begins to become a problem for software "touch" detection is usually around 5mm or 6mm (of commonly used material) between your fingertip and the sensor. If different materials are used this distance changes and can change radically. In keeping with my photovoltaic example, if the material in question could act like a tight bundle of optical fibers (only of course conducting electricity and not light) then the "protective" material could be meters thick without being detrimental to the registration of a touch event.
This is why i think it's almost impossible for it to be the fault of the protector... But everything factor's in. Body weight, blood iron content, protector material impurities, humidity (RH), temperature, skin moisture, variations in the Earth's electrical field from area to area and over time, material thickness, the software algorithm's threshold values, and so on. If they all come together in just the wrong way you could experience the touch registration intermittence you are describing - for sure. And with millions and millions of sensor screens being manufactured it could also be faulty connections there too but /that/ would be my very last guess as they really are ultra-simply constructed. If it's charging at all it should (famous last words) work equally across the entire surface area.
---------- Post added at 01:20 AM ---------- Previous post was at 12:58 AM ----------
Have a look at that poll thread tho:
http://forum.xda-developers.com/poll.php?do=showresults&pollid=9771
416 people report screen separation and almost 130 people report touch-screen malfunction.
That's pretty radical! Maybe it's time to ditch Nexus7 all together?
Click to expand...
Click to collapse
There's been no change in screen sensitivity since I removed the screen protector. I think what you're saying may be correct. I have also noticed intermittent multi touch issues present within certain actions such as pinch to zoom where the touch of the secondary finger is constantly flickering in the sense that the connection between the finger and the touch screen is rapidly switching between being detected and not being detected by the device.
I think at this point, it is almost guaranteed that the screen protector was not the cause of the screen sensitivity issues and that it is a defect within the device itself. I think this is quite unfortunate as I was finally able to get a unit without no sign of screen lift.
Maybe it is time to ditch the nexus 7, however I will not be a part of it as I still think that the nexus 7 is a great device which has many uses along with the added benefit of being a nexus device. Besides, I'm still within my 30 day exchange, so this just gives me a reason to return it and grab the 32GB version.
Sent from my Nexus 7 using Tapatalk 2
Kewl,
Yeah, I'm a total n00b and dunno anything about Nexus7 (nor enough other phones to compare it to anything) so if you think it's worth keeping by all means you should.
BTW, did try popping an iron tab or two?
Bifurcator said:
Yep! The difference between a person with an iron deficiency and someone with a goodly amount can be enormous. In typical variations (say a poor iron intake in the diet compounded by a blood donation or menstruation as opposed to a person eating right and supplementing) can be over two times in terms of touch sensitivity.
If there's zero iron in your blood (besides being in danger of immediate death from organ failure.. ) your touch screen will not be able to detect you at all. The iron in an individual's blood creates strings of capacitors between every epidermal surface of the body. When someone creates a capacitance by touching (or actually even moving into proximity) of the sensor's conductor it creates a capacitance (essentially coupling to ground) by adding a second capacitance (you) in parallel to the sensor's capacitance. When such a ground is introduced the charge-time (frequency) of the sensor slows way down and a "touch" is registered. This is the basic premiss (in brief!) behind Capacitive Touch Sensing (CTS). There's other things going on as well depending on the type of touch screen but almost all of them (found in cell phones) depend on this basic principal.
Fun facts aye? LOL
Click to expand...
Click to collapse
Bifurcator said:
I of course wouldn't know if your sensor was defective or not. But the design is extremely simple and the way they work would imply that if it worked in one area of the screen it will work across the entire screen given that the relative dielectric constant is even throughout the material volume. And if it wasn't you would likely see it as thousands of micro-bubbles, cracks, or other aberrations.
Also keep in mind that temperature and humidity have affect as well.
Click to expand...
Click to collapse
Who is this guy? Stephen Hawking?
I need a bloody iron tab after reading all that !!
Bifurcator said:
Kewl,
Yeah, I'm a total n00b and dunno anything about Nexus7 (nor enough other phones to compare it to anything) so if you think it's worth keeping by all means you should.
BTW, did try popping an iron tab or two?
Click to expand...
Click to collapse
Nope! The problem was isolated only to my Nexus 7 and not my HTC Amaze, so I didn't bother.
Sent from my Nexus 7 using Tapatalk 2
Wilks3y said:
Who is this guy? Stephen Hawking?
I need a bloody iron tab after reading all that !!
Click to expand...
Click to collapse
Hehe...
MidnightXZ said:
There's been no change in screen sensitivity since I removed the screen protector. I think what you're saying may be correct. I have also noticed intermittent multi touch issues present within certain actions such as pinch to zoom where the touch of the secondary finger is constantly flickering in the sense that the connection between the finger and the touch screen is rapidly switching between being detected and not being detected by the device.
I think at this point, it is almost guaranteed that the screen protector was not the cause of the screen sensitivity issues and that it is a defect within the device itself. I think this is quite unfortunate as I was finally able to get a unit without no sign of screen lift.
Maybe it is time to ditch the nexus 7, however I will not be a part of it as I still think that the nexus 7 is a great device which has many uses along with the added benefit of being a nexus device. Besides, I'm still within my 30 day exchange, so this just gives me a reason to return it and grab the 32GB version.
Sent from my Nexus 7 using Tapatalk 2
Click to expand...
Click to collapse
I have been using Huawei G700 for 9 months now but the problem, similar to what you described befell this phone. Sometimes it lags, inaccurate point selections and cant pull the notification bar to the bottom, unless I "hurl" it down. Could it be the screen (no any visible damage) or some internal functioning. I had to reformat it, no solution yet.
I found out what my issue was with the unresponsiveness on my nexus 7 (2013). What it was, was that I didn't remove the protective film from the anti-glare screen protector. I realized it when i was completely going to eliminate the screen protector and see if by doing so my screen would responded better but realized what I was removing was the protective film and not the anti-glare screen protector. My screen is very responsive now.

Stuttery Touchscreen Input

I've been experiencing a strange phenomenon in relation to the touchscreen on my new Nexus 7. It is essentially impossible to capture in video and difficult to accurately describe, so I apologize for any frustration in comprehending my description.
If I open the Play Store (for example) and gently flick to produce a slow automated scroll, the store page will scroll completely smoothly (aside from the usual few dropped frames as images load). However, if I place my finger on the screen and manually scroll through the page by the same amount at the same speed, it visibly stutters. The stutter produced is not absolutely horrible and some people may not even directly notice it, but it is just enough to make manual input feel sticky. On webpages filled with text where stutter will exacerbate even minor ghosting, it is particularly annoying.
The issue is present globally within the OS, although there are certain games which implement further input smoothing and seem to get rid of it. I was somewhat apprehensive about posting this thread, as it an issue which may be too subtle for many people to directly replicate (assuming I do not simply have a defective device, that is) without an exact understanding of what they are looking for and some may think I'm being "too picky".
To further clarify, I am aware that many people have had multi-touch and phantom input issues on this device, but those are not what I am referring to. I have experienced no multi-touch nor phantom input issues whatsoever.
Has anybody else encountered this issue or should I simply organize a replacement? If it is a software issue, I am perfectly willing to wait for Google to rectify it in a future update.
troy2062 said:
I've been experiencing a strange phenomenon in relation to the touchscreen on my new Nexus 7. It is essentially impossible to capture in video and difficult to accurately describe, so I apologize for any frustration in comprehending my description.
If I open the Play Store (for example) and gently flick to produce a slow automated scroll, the store page will scroll completely smoothly (aside from the usual few dropped frames as images load). However, if I place my finger on the screen and manually scroll through the page by the same amount at the same speed, it visibly stutters. The stutter produced is not absolutely horrible and some people may not even directly notice it, but it is just enough to make manual input feel sticky. On webpages filled with text where stutter will exacerbate even minor ghosting, it is particularly annoying.
The issue is present globally within the OS, although there are certain games which implement further input smoothing and seem to get rid of it. I was somewhat apprehensive about posting this thread, as it an issue which may be too subtle for many people to directly replicate (assuming I do not simply have a defective device, that is) without an exact understanding of what they are looking for and some may think I'm being "too picky".
To further clarify, I am aware that many people have had multi-touch and phantom input issues on this device, but those are not what I am referring to. I have experienced no multi-touch nor phantom input issues whatsoever.
Has anybody else encountered this issue or should I simply organize a replacement? If it is a software issue, I am perfectly willing to wait for Google to rectify it in a future update.
Click to expand...
Click to collapse
got the exact same issue with the two i ordered. Sometimes unlicking is a pain or drag and drop an icon to a screen. I"m waiting to get an update. If the next one is the same. i send them back
I thought this was solved in the last update.
Sent from my Nexus 7 using Tapatalk 4
Yup, This is the exact issue I am so frustrated with. I am really hoping this is a fixable issue..
It's a known issue.
I had the same, and fixed by applying this :
http://forum.xda-developers.com/showthread.php?t=2428133
Hopefully it will be fixed in the next release.
But until then, you can use the above solution.
Sent from my Nexus 7 using XDA Premium 4 mobile app
I had this same issue on two nexus 7 devices (one purchased, the other a replacement unit) but eventually returned both over single touch issues. The stutter was apparent especially in chrome when you pinch to zoom. Feedly was another app that would stutter as you scroll down an article. I assumed this was more of an app specific issue but I guess it may be just another touch related issue with the device.
Sent from my BN NookHD+ using Tapatalk 4
AFAIK, this issue is due to the capacitive touch screen not having a very fine resolution input. It is especially noticeable on cheap tablets. The touch screen has input lines running say on a 1x1cm grid. As you draw your finger across, the line whichever is closest to your finger will register. So it will jump from one line sensing the finger to the next one, and this is then input to the software scrolling and produces a stuttering in the scrolling. You can easily try is by slowly drawing the finger up and down and watching the reaction of the page that is scrolling underneath.
To alleviate this, the screen driver can hand over from one line to the next in a smooth gradual manner but of course there will always be a scrolling rate where the effect is worse. The slower you scroll the clearer you can see it.
If lines are close to each other or you have fat fingers, this effect becomes less noticeable.
[edit] having said that, there are always apps which scroll poorly regardless of the quality of the screen.
^I thought that was the issue at first, but now im thinking its a software issue. The slower I move my finger, the less stuttery the animation. It is only when i move my finger at a medium or fast speed that it begins to stutter like this.
juried said:
AFAIK, this issue is due to the capacitive touch screen not having a very fine resolution input. It is especially noticeable on cheap tablets. The touch screen has input lines running say on a 1x1cm grid. As you draw your finger across, the line whichever is closest to your finger will register. So it will jump from one line sensing the finger to the next one, and this is then input to the software scrolling and produces a stuttering in the scrolling. You can easily try is by slowly drawing the finger up and down and watching the reaction of the page that is scrolling underneath.
To alleviate this, the screen driver can hand over from one line to the next in a smooth gradual manner but of course there will always be a scrolling rate where the effect is worse. The slower you scroll the clearer you can see it.
If lines are close to each other or you have fat fingers, this effect becomes less noticeable.
[edit] having said that, there are always apps which scroll poorly regardless of the quality of the screen.
Click to expand...
Click to collapse
This would be a perfectly plausible explanation, however the amount of stutter doesn't really seem to vary at all, regardless of the speed at which I drag.
juried said:
AFAIK, this issue is due to the capacitive touch screen not having a very fine resolution input. It is especially noticeable on cheap tablets. The touch screen has input lines running say on a 1x1cm grid. As you draw your finger across, the line whichever is closest to your finger will register. So it will jump from one line sensing the finger to the next one, and this is then input to the software scrolling and produces a stuttering in the scrolling.
Click to expand...
Click to collapse
Huh? Try an app like 'Yet Another MultiTouch Test' that displays touch coordinates. The touchscreen certainly has single-pixel accuracy/resolution (a pixel is 0.08mm wide).
tni.andro said:
Huh? Try an app like 'Yet Another MultiTouch Test' that displays touch coordinates. The touchscreen certainly has single-pixel accuracy/resolution (a pixel is 0.08mm wide).
Click to expand...
Click to collapse
It has high resolution (different to accuracy btw) due to the driver software working out where the touch is by using all the pick-up dots that show a capacitive response. But in the Nexus you can actually see the capacitive pick-up dots if you hold it in the sun and get the reflection just right, and they are 5mm apart.
Sent from my Nexus 7 using xda app-developers app
I also have the same stuttering issue, mostly in Chrome browser, when scrolling through some websites. Sometimes the tablet will respond to a scrolling glide but sometimes it will not, this is very annoying, another issue that I have is the random "touch - stuck" problem, where a single touch will register at one spot for 1-2 seconds, and you have to touch that spot again in order to un-stuck it, my Nexus 7 FHD has no problem at all when doing the YAMMT app test, there seems to be a lot of bugs in this tablet, I think Asus just sucks in general, my Samsung Nexus 10 has no problem whatsoever...
Sent from my Nexus 7 using Tapatalk 4
juried said:
It has high resolution (different to accuracy btw)
Click to expand...
Click to collapse
What point are you trying to make? The resolution is slightly higher than the display resolution and whatever internal accuracy the touch screen controller has, it is sufficient for that.
due to the driver software working out where the touch is by using all the pick-up dots that show a capacitive response.
Click to expand...
Click to collapse
The Elan touch screen controller has it's own microcontroller that is running some proprietary firmware blob that does all the magic. That firmware reports the position. The OS driver is very dumb and just passes that on.
juried said:
The touch screen has input lines running say on a 1x1cm grid. As you draw your finger across, the line whichever is closest to your finger will register. So it will jump from one line sensing the finger to the next one, and this is then input to the software scrolling and produces a stuttering in the scrolling.
Click to expand...
Click to collapse
But in the Nexus you can actually see the capacitive pick-up dots if you hold it in the sun and get the reflection just right, and they are 5mm apart.
Click to expand...
Click to collapse
That's simply not how things work. The controller measures capacitance at adjacent grid points and determines an interpolated position based on the capacitance measurements. There is no jumping from line to line, the position is smoothly determined using the interpolation.
There are touch screens that only have 2 pairs of grid lines (one pair for X coordinates, one pair for Y coordinates) and rely exclusively on interpolation to determine the position (but they can't support multi-touch).

Categories

Resources