Android: GPS timestamp vs. SensorEvent Timestamp

Question

I just realised that on android the timestamps you get from a GPS Location update are in ms since epoch whereas the timestamps of SensorEvent updates(e.g. of the Accelerometer) are in ns since startup.

I would like to convert the GPS timestamps to the format of the SensorEvent timestamps, does anyone know a good method to do this?

I tried the following: I measured once the time of system startup since epoch:

startupTime = System.currentTimeMillis() - SystemClock.uptimeMillis();

For each gps location update I subtract the startup time:

timestamp = loc.getTime() - startupTime;

But those converted timestamps do still not conform to SensorEvent timestamps, there is still a difference of a couple of seconds...

Answer 1

Do not use SystemClock.uptimeMillis(), since it measures the time since boot without the time where the device was in sleep mode. Instead use SystemClock.elapsedRealtime().