iPhone 5s level and compass issues could be caused by a change in supplier

The iPhone 5s has been widely reported to have bad compass and level readings. According to RealityCap, the issue could be caused due to a switch in suppliers for the accelerometer in the iPhone 5s.

The iPhone 5 doesn't seem to suffer from the issues the iPhone 5s is when it comes to inaccurate compass and level readings. The accelerometer for the iPhone 5 was supplied by STMicroelectronics. The iPhone 5s' part was revealed to be a Sensortech BMA220, which is made by Bosch.

It isn't so much that the supplier itself is the issue, but more that the tolerance levels and what each accelerometer is considering to be an acceptable 'zero-g offset'.

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.

According to RealityCap, the issue could be solved with software on Apple's part but for now individual developers can compensate inside their apps.

A fix from Apple would be the best solution since it would solve problems going forward in which developers don't compensate for the differences in tolerance levels. It will be interesting to see if Apple responds to the issues with a software update for the iPhone 5s.

Source: MacRumors via RealityCap

Allyson Kazmucha

iMore senior editor from 2011 to 2015.

  • Really, none of them are super accurate. Guess because it's Apple we have to whine and forget the cheese..
  • Or, in your case, take whatever Apple give us and be eternally grateful for their sapience and benevolence. Seriously Ally, the problem was not due to a switch in suppliers, it was due to the lack of quality control. A switch in suppliers may have caused a glitch, but it only becames a problem if no one has time to check the new parts.
  • Did you read the post? They have different acceptable tolerance levels, which is causing the discrepancy.
  • Yes, and that's exactly why I posted. That's what I'm calling quality control, checking the actual reading being output by the app, which is obviously not right. If quality control had identified the issue, Apple could have implemented a simple compensation algorithm on iOS7 v1.0.
  • I'm not so sure that's the issue. It may be the actual tolerance rates on the chip itself. But yes, you are right that it should have been caught. And either the chips should have been corrected during production or a software fix should have been implemented on Apple's side.
  • Agree.
  • Doesn't the iPhone 5c use the same Bosch accelerometer as the iPhone 5s?
  • I wouldn't be sure, since the iPhone 5s features the M7, whereas the iPhone 5c doesn't.
  • The M7 merely collects and processes data from the accelerometer, digital compass, and gyroscope so that the A7 doesn't have to. According to iSuppli, the 5c and 5s use the same Bosch BMA220 accelerometer: 5c – http://www.isuppli.com/Teardowns/News/Pages/Apple-Continues-Familiar-Des... 5s – http://www.isuppli.com/Teardowns/News/Pages/Groundbreaking-iPhone5s-Carr...
  • yep. which adds more confusion
  • Thanks for the coverage on this issue. I hope it doesn't fade away as this needs to be addressed by Apple. Do you think it will be fixed in 7.1? Hard to say I guess.
  • You iApologists are hi-la-ri-ous! It doesn't matter what the difference in tolerances is between manufacturer A and manufacturer B. There's a thing called quality assurance testing. Are we to believe that in the run up to releasing the iPhone 5s no one at Apple tested the level and compass functionality? GTFOH with that nonsense....
  • Not sure who's Grandpa got a gold iPhone 5s but could we get a better photo?! Maybe a younger hand? Or is that God cause he's the only one who got a gold one?
  • Well. This is good news! Don't have to swap the phone out, just have to wait for a fix in iOS 7.1.
  • Agree. I've been waiting to hear more about this before I decided to attempt to switch my phone out. I was hoping this was a software fix vs. a hardware issue. Early reports didn't sound good but this makes it sound more promising. My phone is about 5 degrees off which is way more then should ever be allowed.
  • After a chat with apple, here is the fix. It sounds extremely bizarre to me. I'll give it a go when I have some spare time. Did anyone tried that yet ? "Alright. The first step is to back up your information on your device so that you do not lose any data. Then the next step is to update to the latest software ( if you have the latest you will need to do a restore of the software in iTunes) After the update completes, allow the iPhone to charge for at least 90 minutes undisturbed with the display off and Do Not Disturb set to On. It is important that you do not move the device during this period."
  • Sounds utterly ridiculous! I think the Apple rep's imagination was working overtime!
  • This is exactly what I told them. I said "ehhh are you serious ?" This guy said it was the permanent fix and will be release to public soon, but I just think they are taking the p***