The iPhone 5s’ accelerometer/gyroscope bugs could be caused by a new chip

[RaduTyrsina]

If you’ve been having issues with your newly acquired iPhone 5s’ accelerometer, then you are not the only one. Multiple tech websites and Apple support forums users have reported a hardware bug with the iPhone 5s’s accelerometer and gyroscope sensors. The glitch has been detected in accelerometer-based apps and Apple's Compass app and other apps that make use of the gyroscope.

iPhone 5s users have been complaining on Apple’s support forums about numerous bugs and glitches that they encounter when using gyroscope or accelerometer-based apps. Some of them have noticed the issues when playing games. As you can see in the above short GIF animation made by Gizmodo, it appears that during EA's Real Racing 3 game, a phantom leftward tilt is detected which causes the car to turn left even if you didn’t move your iPhone 5s.

RealityCap’s CEO Eagle Jones is the one who seems to have found the culprit for this issue. He has analyzed a teardown of the iPhone 5s and observed that the iPhone 5s uses the Bosch Sensortech BMA220 accelerometer sensor, which is different from iPhone 5’s STMicroelectronics chip. He said the following, claiming that even if both chips have similar consistency in measurement, the Bosch device has a larger measurement 'bias' and a different 'zero-g offset' value:

”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.”

Have you experienced some similar issues on your iPhone 5s?

Source: Gizmodo