Moving the hand
In order to move the servos, you can use a servo controller similar to the one introduced in Chapter 3, Building a Wall-E Robot, to control six servos that will control these fingers, thumb, and wrist. As in Chapter 3, Building a Wall-E Robot, the servo controller you are going to use for this project is a simple servo motor controller utilizing USB from Pololu. Since you only need to control five servos, you can order the six servo controller version available at http://www.pololu.com.Here is an image of the unit:
Make sure you order the assembled version. This piece of hardware will turn USB commands from the Raspberry Pi into signals that control your servo motors. There are two connections that you'll need to make to the servo controller to get started; the first to the servo motors, the second to a power source.
First, connect the servos to the controller. In order to be consistent, let's connect your six servos to the connections marked 0 through 5 on the controller...