Motion Logger is a utility for researchers, educators, and other interested parties who wish to log sensor data from the iPhone and email the results in a CSV file for further analysis or exploration. The app permits collection of data from the phones CoreMotion Services (Accelerometer, Magnetometer, and Gyroscope) as well as from the phones CoreLocation services (GPS and Heading). During data collection, data is logged independently for each service enabled by the user, and a separate CSV file is provided for each of those services. A timeout period for data collection may be set, and data may be collected for a maximum time of 1 hour, 59 minutes, and 59 seconds. GPS and Heading data are logged as they become available from the CoreLocation service (approximately once-per-second for GPS in "Best" accuracy mode). Data for the Accelerometer, Magnetometer, and Gyroscope are logged on an independent queue at a user-configurable rate from 1 to 100Hz. All data logged for each of the services is referenced to the same time base.
The data returned for each of the services is:
GPS: latitude (degrees), longitude (degrees), horizontal accuracy (meters), altitude (meters), vertical accuracy (meters), speed (m/s), course (degrees), time (seconds)
Heading: magnetic heading (degrees), true heading (degrees), heading accuracy (degrees), x-axis geomagnetic field (microTesla), y-axis geomagnetic field (microTesla), z-axis geomagnetic field (microTesla)
Accelerometer: x-axis acceleration (g), y-axis acceleration (g), z-axis acceleration (g), time (seconds)
Magnetometer: x-axis raw magnetic field (microTesla), y-axis raw magnetic field (microTesla), z-axis raw magnetic field (microTesla), time (seconds)
Gyroscope: x-axis rotation (radians/sec), y-axis rotation (radians/sec), z-axis rotation (radians/sec), time (seconds)
The app provides a simple, clean interface and does not include advertisements. In the design of this app, attention was focused on keeping a small memory footprint and allowing users to easily erase unneeded data. Please note that due to constraints set by the iPhone operating system, this app will not collect data in background mode.