New Accelerometer Supplier Could Be Causing Incorrect iPhone 5s Level and Compass Measurements
A new supplier for the accelerometer part in the iPhone 5s could be causing incorrect level and compass measurements in the new device, an issue that was first noticed earlier this month.
RealityCap CEO Eagle Jones read into the Chipworks teardown of the iPhone 5s (via Gizmodo) and noticed that the phone uses the Bosch Sensortech BMA220 as its accelerometer. The iPhone 5, for example, used an accelerometer from STMicroelectronics.

Both devices have similar consistency in measurement, but the Bosch device has a larger measurement 'bias'. The end result, as Jones notes, is that the new accelerometer has a different 'zero-g offset' which would need to be compensated for in software.
The second key spec for accelerometers is the zero-g offset, or bias. This indicates the range for a roughly constant offset that will be added to every output sample of data due to manufacturing variance. This can also change over time due to mechanical stress or temperature variation. 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.
He goes on to note that developers can compensate for the increased offset because it is unlikely to change significantly from one measurement to another, though Apple could do a system-wide fix at the OS level to ensure accurate measurements in the future.
Popular Stories
Apple today announced that its next-generation CarPlay experience, now dubbed "CarPlay Ultra" begins rolling out today, starting with Aston Martin vehicles.
Subscribe to the MacRumors YouTube channel for more videos.
CarPlay Ultra is now available with new Aston Martin vehicle orders in the U.S. and Canada. It will also be available for existing models that feature the brand's next-generation ...
Apple's recently announced CarPlay Ultra promises a deeply integrated in-car experience, but not all iPhone users will be able to take advantage of the new feature.
According to Apple's press release, CarPlay Ultra requires an iPhone 12 or later running iOS 18.5 or later. This means if you're using an iPhone 11, iPhone XR, or any older model, you'll need to upgrade your device to access...
Apple today released iOS 18.5 and iPadOS 18.5, the fifth updates to the iOS 18 and iPadOS 18 operating systems that came out last September. iOS 18.5 and iPadOS 18.5 come a little over a month after Apple released iOS 18.4 and iPadOS 18.4.
The new software can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update. The iOS 18.5 update has a...
President Donald Trump has asked Apple CEO Tim Cook to halt the company's manufacturing expansion in India, in a potential disruption of Apple's plan to shift iPhone production away from China.
"I had a little problem with Tim Cook yesterday," Trump said during his state visit to Qatar, according to Bloomberg. "He is building all over India."
"They [India] have offered us a deal where...
Apple this week introduced a new feature designed to allow prospective Apple Music users to import their saved music and playlists from third-party music services to Apple Music.
The feature is either in an expanded testing phase or it has started rolling out, and it is available in Australia and New Zealand according to an Apple Support document. Signs of the transfer option first surfaced...
Apple today announced the launch of CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles.
CarPlay Ultra features deep integration with a vehicle's instrument cluster and systems, built-in Radio and Climate apps, customizable widgets, and more. The interface is tailored to each vehicle model and automaker's identity, and drivers can also adjust...
The first videos of Apple's CarPlay Ultra experience are now available, providing a never-before-seen look at the long-anticipated iPhone-linked infotainment software.
British automaker Aston Martin today shared the first video of Apple's CarPlay Ultra experience in-action, followed by a detailed walk-through of the CarPlay Ultra system on Top Gear's YouTube channel, which provides the...