Summary

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• the 2 lines LCDs has been replaced by 2 Nokia5110 graphic LCDs (at first, I wasn't sure at first if both could be driven separately)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

Print Settings

Printer:

Tronxy X1

Rafts:

No

Supports:

Yes

Resolution:

0.2mm

Infill:

10%

Notes:

Here are some Cura settings for the supports, they work like a glove:

• support model: lines
• overhang angle: 60°
• fill amount: 10%
• distance XY: 2mm
• Distance Z: 0.15mm

For the general settings print:

• support type: everywhere
• layer height: 0.2mm
• 10% infill
• 8mm Brim
• No Raft

You can print quite fast especially for the base, middle and megaContainer sections.
The lego pins on the head need some precision for the addons to fit well.

Post-Printing

For the mounting:

• the base receive the hips servos (and a charge plug I added after)
• the middle section receive the power button (where you have room), battery pack and the 5V and the 6V power sources
• the megaContainer, I'll let you guess
• the head gets the LCDs, a prototype breadboard and the bluetooth module

You can get the code at: https://github.com/ka3ros/chip-E_Remix

I tried to add a period parameter to the home(unsigned int period) method to make the move smoother but I still find it's too hasty.

How I Designed This

I'm quite new to 3D Printing (only 2 months) and modelling (only some tests before the challenge) so I find this little buddy really interesting because it's easy to print, has a very open design and the standard functions are already quite enjoyable.
Everything has been designed under blender and I learned a lot at least to build manifold objects instead of vertices magma.
It's my first complete arduino project. Obviously not the last.
The HC-06 bluetooth module is already wired but the android app will start after the holidays.
The bluetooth android app will start
Next evo, maybe a grappling hook.

Custom Section

The Arduino code

I mainly worked on the dual LCD library which is still in progress.
Functions are open the eyes, close, blink, look in 8 directions that can be synced with the robot moves.

The walking code is really basic and I just added some test to detect obstacles within the current position and the next (4 steps x cm/step + sensor min distance detection ~= 10 cm).
If an obstacle is detected, the robot turns on the left and try to continue.