Apple's iPhone 5s sensor woes may be linked to new accelerometer supplier

Posted:
in iPhone edited January 2014
Owners of Apple's latest flagship iPhone 5s have been experiencing issues seemingly related to the handset's on-board sensors, and a new report claims the use of a new accelerometer supplier may be to blame.

Accelerometer


Following up on a report from early October, Gizmodo reported on Wednesday that a switch in Apple's accelerometer suppliers may likely be the cause of misreadings seen in the iOS 7 Compass app.

According to a teardown by Chipworks, the iPhone 5s now uses an accelerometer made by Bosch Sensortech, while older models of the smartphone employ STMicroelectronics silicon. Interestingly, STM still makes the three-axis gyroscope in the 5s.

Because component specifications differ from manufacturer to manufacturer, the new part does not behave in the same manner as those found in previous iPhones, meaning apps accessing its raw data will output incorrect readings. In our own anecdotal testing, we found the Compass app's level to be off by some three to five percent against a physical tubular spirit measure, even after recalibrating multiple times.

A more precise assessment of the apparent discrepancy was shared by RealityCap, a company specializing in sensor-based real-time 3D location software for iOS. As CEO Eagle Jones explained in a blog post, an accelerometer's accuracy relies on variance, or the consistency in readings, and bias, or constant inaccuracy due to manufacturing flaws.
This is where we find the problem: the typical bias for the ST part is +/- 20mg, while the Bosch part lists +/-95mg. This almost 5x greater offset range is confirmed by our measurements, and is absolutely consistent with the failures being reported by users and the media. Specifically, a +/- 20mg offset range would translate to around a +/-1 degree accuracy range in tilt detection, and a +/-95mg offset translates to +/-5 degrees in tilt.
According to Jones, Apple would be able to remedy the issue by building in a recalibrated firmware bias at the factory. Alternatively, manual calibration can theoretically be accomplished on an app-by-app basis, a solution RealityCap is currently working on.

For its part, Apple remains mum on the matter.
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Comments

  • Reply 1 of 40
    So is this something that they just need to recalibrate the software parameters (ie software update) or does it require a swap out for new hardware?
  • Reply 2 of 40

    Accelerometergate?

  • Reply 3 of 40
    dasanman69dasanman69 Posts: 12,931member
    pkabir wrote: »
    So is this something that they just need to recalibrate the software parameters (ie software update) or does it require a swap out for new hardware?

    That would work if they're all off by the same margin, if not it needs to be user adjusted.
  • Reply 4 of 40

    I have a 5S but I have no way to know if the level is accurate or not - there's not a single thing in my home that's level or plumb. No walls, no floors, no doors... everything is crooked or tilted. The joys of living in a 100+ year old house hehehe. :D 

     

    Anyhow, if I do want to put up a shelf or hang a picture, I think I'll use a $5 hardware store level, and maybe not precariously balance my $700 phone while doing DIY home projects.

  • Reply 5 of 40

    As an Apple fanboy, I must say, if true, this is looking like a botch release, from Apple's normal standards. Not entirely Apple's doing, but indirectly still tarnishes the brand. 

     

    Definitely get the AppleCare this go around! 

  • Reply 6 of 40
    atashi wrote: »
    I have a 5S but I have no way to know if the level is accurate or not - there's not a single thing in my home that's level or plumb. No walls, no floors, no doors... everything is crooked or tilted. The joys of living in a 100+ year old house hehehe. :D  

    Anyhow, if I do want to put up a shelf or hang a picture, I think I'll use a $5 hardware store level, and maybe not precariously balance my $700 phone while doing DIY home projects.
    Well if nothing is level in your house the 5s is perfect for you, the offset error might work in your favor.
  • Reply 7 of 40
    Quote:
    Originally Posted by AppleInsider View Post

     
    This is where we find the problem: the typical bias for the ST part is +/- 20mg, while the Bosch part lists +/-95mg.

    I wonder how much cheaper the Bosch part is? :rolleyes:

  • Reply 8 of 40
    Quote:

    Originally Posted by Richard Getz View Post

     

    As an Apple fanboy, I must say, if true, this is looking like a botch release, from Apple's normal standards. Not entirely Apple's doing, but indirectly still tarnishes the brand. 

     

    Definitely get the AppleCare this go around! 


     

    To be fair, there are parts of The Matrix where the gravitational field is not entirely stable.

  • Reply 9 of 40
    hentaiboy wrote: »
    I wonder how much cheaper the Bosch part is? :rolleyes:

    May not be cheaper at all. Apple is trying to have more than one source for some components to insure shipments or needs multiple sources for capacity... Both are smart moves.
  • Reply 10 of 40
    hentaiboy wrote: »
    I wonder how much cheaper the Bosch part is? :rolleyes:
    5%, same as error difference :-D
  • Reply 11 of 40
    i'm heavily involved in GPS and accelerometer development. The new sensor doesn't explain the compass readings being off by 11-13 degrees -- which is alarming for me and anyone who relies on compass readings. in our testing, the 5S is always off by 11-13 degrees, while the 5 and the 4S are consistent. the magnetometer is definitely off, much more so than the accelerometer. i suspect the problem might be in the translation between the 64 bit architecture and 32 bit software, or perhaps the software translating the sensor equipment readings is defective. i truly hope it's not a hardware problem because that would imply a fix that won't reach millions of our customers.
  • Reply 12 of 40
    Quote:

    Originally Posted by Richard Getz View Post

     

    Definitely get the AppleCare this go around! 


     

    Getting the AppleCare Protection Plan just to fix this problem is maybe a bit over the top, since Apple already offers a 1 year limited warranty by default.

  • Reply 13 of 40
    Quote:

    Originally Posted by peter zulu View Post



    i'm heavily involved in GPS and accelerometer development. The new sensor doesn't explain the compass readings being off by 11-13 degrees -- which is alarming for me and anyone who relies on compass readings. in our testing, the 5S is always off by 11-13 degrees, while the 5 and the 4S are consistent. the magnetometer is definitely off, much more so than the accelerometer. i suspect the problem might be in the translation between the 64 bit architecture and 32 bit software, or perhaps the software translating the sensor equipment readings is defective. i truly hope it's not a hardware problem because that would imply a fix that won't reach millions of our customers.

    and or the M7?

     

    I'm finding the software for using the compass and accelerometer  on the 4s under 7.0.2 ( compass and inclinometer ) seems a bit flaky.  compass seems to 'lockup' at crazy declinations for minutes and then oscillating then locking up.   my iphone 5 under iOS 6 was not nearly as crazy.  

     

    now under 7 both phones seems to be crazy sensitive accelerometers compared to the prior iOS release.   So I doubt it's HW, and more a SW issue.

  • Reply 14 of 40
    Quote:

    Originally Posted by Macky the Macky View Post





    May not be cheaper at all. Apple is trying to have more than one source for some components to insure shipments or needs multiple sources for capacity... Both are smart moves.

    Doubt that.  the 5s isn't dual sourcing it's accelerometers.

     

    It's also been discussed that the power requirements, and the net size of the Bosch chip are smaller, with size being the likely differentiator.   I strongly doubt this is dual sourcing.

  • Reply 15 of 40
    Quote:

    Originally Posted by Atashi View Post

     

    I have a 5S but I have no way to know if the level is accurate or not - there's not a single thing in my home that's level or plumb. No walls, no floors, no doors... everything is crooked or tilted. The joys of living in a 100+ year old house hehehe. :D 

     

    Anyhow, if I do want to put up a shelf or hang a picture, I think I'll use a $5 hardware store level, and maybe not precariously balance my $700 phone while doing DIY home projects.


    get inclinometer... it has a calibration mode that takes 'flat but unlevel' under account.

     

    but for the most part, the $5 level is a better tool for the job.  (I do like the iPhone for leveling furniture, however).

     

    -ToG (in a 120yo house.... It's amazing how much .2deg slope makes a difference for 8'x6' bookshelves;-)... or worse... when new work is level against floors and ceilings that are not;)

  • Reply 16 of 40
    Quote:

    Originally Posted by TheOtherGeoff View Post

     

    and or the M7?

     

    I'm finding the software for using the compass and accelerometer  on the 4s under 7.0.2 ( compass and inclinometer ) seems a bit flaky.  compass seems to 'lockup' at crazy declinations for minutes and then oscillating then locking up.   my iphone 5 under iOS 6 was not nearly as crazy.  

     

    now under 7 both phones seems to be crazy sensitive accelerometers compared to the prior iOS release.   So I doubt it's HW, and more a SW issue.


    The Maps app does that on my iPhone 5 sometimes.  When I'm in an area with little or no data coverage and weak GPS the maps app will oscillate back and forth especially if I come to a stop.  It will even do it if I'm driving down the road.  I'm starting to think this may be a combination of iOS7 and hardware issues.

  • Reply 17 of 40
    maestro64maestro64 Posts: 4,071member

    Just another example of people focusing on things that do not mater. For those who are relaying on an iphone to make your house level or keep you from getting lost in the woods, you deserve to live in a crooked house and be lost in the woods.

     

    There is a saying which is true in this case, use the right tool for the right job. Remember the fact the phone can do these things was never its intended purpose, therefore, The fact the phone can do these thing makes it good enough. Otherwise, if you want precision then you need to buy the right tool. 

  • Reply 18 of 40
    Quote:
    Originally Posted by razorpit View Post

     

    The Maps app does that on my iPhone 5 sometimes.  When I'm in an area with little or no data coverage and weak GPS the maps app will oscillate back and forth especially if I come to a stop.  It will even do it if I'm driving down the road.  I'm starting to think this may be a combination of iOS7 and hardware issues.


    No, that just typical behavior for an A-GPS device (such as phones) when you have no data connection and weak GPS signal. In such a situation the error margin for calculating the location grows much bigger and as such it will appear as if you might be in multiple places due to the inaccuracy. I've seen such effects happen on Android phones with Google Maps as well and on iOS 6 and earlier in the same circumstance.

  • Reply 19 of 40
    icoco3icoco3 Posts: 1,408member
    Quote:
    Originally Posted by Suddenly Newton View Post

     

    Accelerometergate?


     

    No...Sensorgate (it's inclusive)

  • Reply 20 of 40
    maestro64maestro64 Posts: 4,071member
    Quote:

    Originally Posted by razorpit View Post

     

    The Maps app does that on my iPhone 5 sometimes.  When I'm in an area with little or no data coverage and weak GPS the maps app will oscillate back and forth especially if I come to a stop.  It will even do it if I'm driving down the road.  I'm starting to think this may be a combination of iOS7 and hardware issues.


    Actually the phone is using 1 or 3 method to figure out where the phone is, first is simple cell tower locations, if are connected to the tower and that has a known location the phone can approximate your locations, next it will use a WiFi signal since those may have a location based on a database that apple and other companies have collected, Lastly is using the GPS which is going to triangulate your exact location with in a few feet. Apple most likely has an algorithm which used all three of these methods depending on what is going on at any particular time.

     

    To prove this to yourself, turn off wifi, then turn off your phone for a period of time, then go in a structure like a house (shielded form a GPS signal) turn the phone back on, and bring up maps, and your location will be based on the cell tower location. Then turn on Wifi and your location will get a little better, then walk outside and then your location will become even better.

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