Reddit user, Glarznak, was on vacation when his iPhone 5s ran out of juice. When he returned home to check on his Argus activity tracker, he noticed that it was capable of tracking his steps, despite the phone’s inability to function. Here is his own account of what happened:
While traveling abroad, my iPhone cable stopped working so my 5s died completely.
I frequently use Argus to track my steps (highly recommended if you have any health bands or accessories) since it takesadvantage of the M7 chip built into the phone.
Once I got back from my vacation and charged the phone, I was surprised to see that Argus displayed a number of steps for the 4 days that my phone was dead.
I’m both incredibly impressed and slightly terrified.
The Argus uses the iPhone 5s M7 co-processor that’s also in the iPad Air and the iPad mini 2 with retina display. The M7 works in tandem with the a7 processor and uses information from your phone’s accelerometer, gyroscope, and compass with a significantly small amount of energy to track your movement. As a separate processor, it can continue to work if the main one goes to sleep, thereby allowing the phone or tablet to continue motion monitoring despite low processing power – or, in this case, nearly zero energy after five days without charge. Having the processor is extremely useful for activity monitoring. Apps like Argus can use the processor’s always-on status to track its users even when the phone is seemingly dead.