Question

Is there a way to get the velocity without GPS in Android? I don’t need the accurate values.

Answer 1

Well, sort of, but you will need to do alot of processing..

You can make frequent accelerometer readings and integrate the values once to get velocity. This won’t get you an accurate starting velocity but after a while it will probably work (unless you start when the phone is driving along in a car). See also this post.

Now, some pseudo code:

We start at t=0 and measure acceleration in all three axis.

a = get_acceleration()

vx = vx + a.x - gravity.x;
vy = vy + a.y - gravity.y;
vz = vz + a.z - gravity.z;

After doing this for a few seconds, the sum of all the acceleration values (if you sample frequently, ie, 50Hz) should be velocity. You will also need to work out which way up your device is and therefore how much of the acceleration components you are reading is due to gravity and compensate.