hexapod/README.md

# <img src="./imgs/hexapod-logo.svg" alt="logo" width="64"/> Hexapod

A Hexapod Robot using Raspberry Pi Zero W

![banner](imgs/banner.jpg)

## Introduction

This is a hexapod robot based on [Smallp Tsai](https://github.com/SmallpTsai)'s [hexapod-v2-7697](https://github.com/SmallpTsai/hexapod-v2-7697) project.
This project reused most of the mechanism design in the original project, but with a totally redesign on the circuits and softwares.
The table below shows the difference between this project and the original one.

|                 | Original hexapod-v2-7697 | This project                                    |
| --------------- | ------------------------ | ----------------------------------------------- |
| Controller      | Linkit 7697              | Raspberry Pi Zero W or Raspberry Pi Zero W 2    |
| PWM control     | Custom circuit board     | 2 x PCA9685 motor driver boards                 |
| DC-DC           | 7 x mini360 modules      | 2 x XL4005 5A Max DC-DC modules and 1 x mini360 |
| Power           | 2S Lipo battery          | 2 x 18650 batteries                             |
| Remote          | BLE                      | WiFi                                            |
| Remote software | Android and iOS          | PC, Android (WIP)                               |


## Mechanism

### Bill of Materials

#### Servo - MG92B

Servo is the key component. I use TowerPro [MG92B](http://www.towerpro.com.tw/product/mg92b/). It has metal gear (important!).
An hexapod requires 18 of them.

> The dimension of 3d printed part is highly depended on servo's dimension. Modification is required if you want to use other alternative servo. 

#### 3D-Printed Parts

##### Body x 1

Filename | Thumbnail | Required |
-------- | --------- | -------- |
body_top | ![body_top](imgs/body_top.jpg) | 1 |
body_bottom | ![body_bottom](imgs/body_bottom.jpg) | 1 |
body_center | ![body_center](imgs/body_center.jpg) | 1 |
body_side_wall | ![body_side_wall](imgs/body_side_wall.jpg) | 2 |
body_back_wall | ![body_back_wall](imgs/body_back_wall.jpg) | 1 |

##### Leg x 6

Filename | Thumbnail | Required |
-------- | --------- | -------- |
thigh_top | ![thigh_top](imgs/thigh_top.jpg) | 1 (x6) |
thigh_bottom | ![thigh_bottom](imgs/thigh_bottom.jpg) | 1 (x6) |
joint_cross | ![joint_cross](imgs/joint_cross.jpg) | 1 (x6) |
joint_top | ![joint_top](imgs/joint_top.jpg) | 2 (x6) |
joint_bottom | ![joint_bottom](imgs/joint_bottom.jpg) | 2 (x6) |
leg_top | ![leg_top](imgs/leg_top.jpg) | 1 (x6) |
let_bottom | ![leg_bottom](imgs/leg_bottom.jpg) | 1 (x6) |
foot_top | ![foot_top](imgs/foot_top.jpg) | 1 (x6) |
foot_bottom | ![foot_bottom](imgs/foot_bottom.jpg) | 1 (x6) |
foot_ground | ![foot_ground](imgs/foot_ground.jpg) | 1 (x6) |
foot_tip | ![foot_tip](imgs/foot_tip.jpg) | 1 (x6) |

#### Others

Name | Spec | Thumbnail | Required | Note
---- | ---- | --------- | -------- | ----
Screw | M2 6mm | ![6mm](imgs/M2_6mm.JPG) | 54 | Servo Arm: 1 x 18<br>Joint: 4 x 6<br>Thigh: 2 x 6
Screw | M2 10mm | ![10mm](imgs/M2_10mm.JPG) | 24 | Thigh: 1 x 6<br>Pin lock: 1 x 18
Screw | M2 30mm | ![30mm](imgs/M2_30mm.JPG) | 36 | Servo: 2 x 18
Nuts | M2 | ![6mm](imgs/M2_nut.JPG) | 36 | Servo: 2 x 18
Pin (304) | M4 6mm | ![pin](imgs/pin_M4_6mm.JPG) | 18 | Servo: 1 x 18

### Leg Assemble

![LegAssemble](imgs/mech_leg_exploded.jpg)

Please check [Leg Assemble](LEG.md) for more detail instructions

Leg assembly instruction video https://youtu.be/oaAE5fC09KQ is also available.
<a href='https://youtu.be/oaAE5fC09KQ'><img src='http://img.youtube.com/vi/oaAE5fC09KQ/mqdefault.jpg'/></a>

> Note. Total 6 Legs are required.


## Skill requirement

If you want to make one hexapod by yourself. You should at least knows how to:

* Mechanism part
  * Use `3D printer` to print a model.
  * Able to adjust 3D model to fit your custom need.
* Electronics
  * Make a `PCB` (suggest to use professional PCB services)
  * Soldering `SMD` component (0805 and TSSOP28)
  * How to use/charge/store `LIPO batteries`
* Software
  * Use `Linkit 7697` (ie. upload and run any program)
  * Use `LRemote` to communicate 7697 and your mobile phone

## Table of Content

1. [Mechanism](mechanism/) - How to build the body
1. [Electronics](electronics/) - Circuit explanation
1. [Software](software/) - The software running on Linkit 7697