[efoote868]

As others have mentioned, you will get small errors in your measurements which can accumulate when you add them together for a long period of time.

There are things you can do to try and mitigate these errors. For an accelerometer, try to keep the vibrations hitting it as minimal as possible. This means mount it to a most rigid part of your robot (towards the center) with a damper material (such as a soft foam) in between. Also, handle the sensor with care. Every accelerometer I know of has a G tolerance, which will be on the order of 100s -1000s of Gs. Any jerk (think collision or bounce) more than this will ruin your sensor, and you won't be able to tell just by looking at it.

The last thing I'd suggest you do would be to thoroughly test your code and your setup to understand it's limitations - if the error becomes too large after 10 seconds then you probably won't want to use it for more than autonomous mode.