I have bought two servos by parallax/futaba that I want to use for a robot. I am experimenting a bit with them to understand how I control them. If I use the servo library with Arduino I can make them rotate, but I do not know if I can change the speed and direction. What values should I use with the write-routine in the library?
You need to experiment with mid-range values (say 90 +/- 10 degrees).
If you print the values, note where the servo stops moving / changes direction. The values may be different for each "servo".
For finer control, you can specify pulse widths in microseconds (from about 544 to 2500), instead of angles.