Chip-3v0

Hello everyone, here's my humble remix of the Chip-E.

Here are the changes:
- the body:
- the head has been covered by compatible lego plates generated with openscad and the library from projunk
- the base and middle received compatible technic L beams also generated with openscad and the technic L-beam library again from projunk
- a body part has been inserted between the middle and head sections to store an arduino mega
- every section is bound to others with compatible lego technic friction pins (the black ones)
- it has now a nose and the head section has been elevated to receive the LCD replacement.

Now let me introduce the electronic parts:

• the 2 lines LCDs has been replaced by 2 Nokia5110 graphic LCDs (at first, I wasn't sure at first if both could be driven separately)
• an HC-SR04 ultrasound sensor in the middle section for obstacles avoidance and in the future SLAM(Simultaneous Localization And Mapping)
• a HC-06 bluetooth module to use with and android phone as remote controller => wired on RX3 and TX3
• the battery pack is a 2S or 7.4V
• the servos have a 6V source
• the Mega/screens/HC-SR04 and HC-06 are powered by a ubec also wired on the 2S pack.

While the pins on the head mostly are mostly for fun and decoration (like beautiful Skyrim helmet horns), the technic beams on the base and middle section are real strong anchors to add physic functionalities like animated arms. The Arduino mega allows also lots of other functionnalities (voltage sensor for self battery depletion detection, ...).

Some testing videos:

First tests of walking (2sec then 1 sec periods)
https://www.youtube.com/watch?v=mcLu4BAvRUA

Starting up then go for a walk:
https://www.youtube.com/watch?v=p_Q9QmQ-M0A

Obstacle detection:
https://www.youtube.com/watch?v=ZIjLggfGIAk