I am writing an app that records accelerometer data in the background. When we call sensor.accelerometerData(from:to:), the for loop when iterating CMSensorDataList suspends/pauses as the watch screen turns off and resumes when app comes to foreground. Is there a way we can keep the processing on until it completes? I used Location Updates capability in Background Modes as a hack but it will make my app rejected from App store just to acquire capability for background execution. Please note that our data is comprised of larger sets, say hours. We retrieve data in batches of 30 minutes each but this also does not complete.

I am trying to parse CMSensorDataList in watchOS. The maximum batch of data is comprised of 30 minutes. The sampling rate is 50Hz, which makes it 90,000 records for 30 minutes. We iterate over each item and finally write the data to a CSV file. As this is a slow processing keeping in view the execution limits of watchOS, the process suspends when app goes to the background. This way, it takes too much time to parse a significant time data. My question is, is there a way we can serialize this CMSensorDataList as a whole and transfer it to the phone using WCSession? Or is there another effective way to achieve this?