I'm having trouble getting the main feature of my iOS application to work. I'm trying to create an app that measures the amount of movement over a period of a few hours using CoreMotion. All works fine when the device is awake, however the issue is that the device auto locks after a while and enters the background state, thus my methods for monitoring movement pause.
I'm searching for a possible solution to recording the device's movement whilst it has been locked, which may be to keep the app awake for a few hours at a time. I've looked into a bunch of possible solutions that have been used for this in the past, yet found out that these ways of doing it can now cause the app to be rejected by Apple.
Any help would be much appreciated please.
For anyone who is interested or stuck on a similar problem I figured out the solution to my question. I needed to utilise the iPhone's motion coprocessor, which tracks movement overtime and stores this data on the device. This is part of the CoreMotion framework and can be queried regardless of whether the application was open or not at the time of use. It's also worth mentioning that only the iPhone 5s and later have this hardware, so older devices will no be able to take advantage of this.
I hope this helps anyone who needs it.