Robot shield for Arduino @ Open Electronics.

The idea behind this post is to bring together some robot designs and trasform them in a new device with new hardware and standard software (arduino of course) and so easier to use.  These robots have three things in common: a mechanical structure, the hardware and the software. While the mechanical part is necessarily different, we wanted to understand if there was a hardware board that could be common, with a unique development system. The choice, quite obviously, has the Arduino board, which with its development environment is perfect to create similar projects. The first consideration that came to our mind is like the Arduino board can manage a large number of servos, eight in the case of the robot SPIDER. Arduino can be powered through the plug with a voltage between 6 to 12 volts, his voltage regulator provides the 5 V stabilized, necessary for the operation of our shield. We could  power our robot with rechargeable batteries. A standard servo requires a supply voltage of 4.8 to 6 volts, easily obtainable with four batteries in series, at full charge, provide 1.5 x 4 = 6 volts but towards the complete discharge provide just 1.0 x 4 = 4 volts. We are not in optimal conditions for the servos.  Throughout this reasons we decided to create a special shield, already prepared for all these functions, it is easy to install and use.