Moving the Finch robot

The setWheelVelocity method turns the wheels

setWheelVelocities(int leftVelocity, int rightVelocity)
This method simultaneously sets the velocities of both wheels.

setWheelVelocities(int leftVelocity, int rightVelocity, int timeToHold)
This method simultaneously sets the velocities of both wheels for a certain amount of time.
If timeToHold is positive, this method blocks further program execution for the amount of time specified by timeToHold, and then stops the wheels once time has elapsed.
(meaning you don't need to add your own sleep command to give the robot time to move, it's built into this method)

stopWheels()
Stops both wheels.

valid velocity values range from -255 to 255; negative values cause a wheel to move backwards.

Problem: The Finch doesn't move straight or turn accurately

The Finch's movements are not repeatable - a timed turn that moved 90 degrees might move 110 degrees the next time.

Cause: The Finch's tether makes repeatable movements difficult - turns cause the tether to twist, causing a spring force that tends to resist continued turning in the same direction. The tether may also drag on the Finch causing it to turn slightly when it should move straight. You can minimize the effect of the tether by:

Holding the tether overhead while the Finch is moving.
Adding weight to the Finch (pennies taped to the underside work well).
Avoiding activities and assignments that call for accurate movement - the Finch will not do well in maze navigation, but will follow a light source just fine.

Ultimately, inaccurate movement is the main drawback of the tether. The Finch could be wireless, but the cost of a wireless tether + batteries would nearly double the Finch's retail price.