Rapid Android Development

Record Sensor Data into a SQLite Database

To see how useful a database can be, let’s go one step further and create an app that lets us record sensor data directly into a SQLite database table. We’ll then use SQL queries to browse the sensor data we’ve recorded from the accelerometer and visualize the data on the Android screen as a time series.^[246] A time series plots data points recorded at fixed intervals. For our example, we will record a data point every time we receive a new accelerometer value.

Alongside the accelerometer sensor values x, y, and z, we’ll record time as Unix time (measured in milliseconds since January 1, 1970 UTC^[247]) using Android’s System method, currentTimeMillis.^[248] This allows us to identify precisely at what ...