Crufty is a 'robot' rover made from 'maker cruft'; those things likely to be filling the drawers/storage boxes/garages/cellars/Hackspaces of people who make stuff with small board computers, microcontrollers and 3D printers. Crufty deliberately uses older versions/tech so lower performance/outdated hardware can be repurposed.
The hardest part to source will be hoverboards with the same controllers used in this build, it's a bit of a pot luck what is fitted. If the project is successful I may try and document builds for other common hoverboard controllers.
The intention is that Crufty can be made for a comparatively small outlay and used as a 'learning platform' for Robot OS (ROS) without purchasing large amounts of expensive stuff. Crufty is much bigger than a typical tabletop/indoor robot made with small DC brushed motors but scales many of the usual ideas up so Crufty can be used outdoors (although sunlight stops the Kinect working).
This repository is a rough how-to/log of building Crufty so I can collect hard to find information in one place.
- Very basic woodworking/fabrication
- Soldering
- 3D printing (mostly for ease, you could fabricate everything needed with basic tools instead)
- Basic experience with Arduino coding (on any platform, but examples will be created on Windows 10)
- Basic experience with Linux (for the Raspberry Pi/ROS)
- A computer that can run ROS (any platform, but examples will be on Ubuntu 20.04 LTS)
- ST-Link v2 for flashing the Hoverboard controllers
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Two self balancing hoverboards (with Gen 2 controllers specifically supported by the hack firmware)
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Raspberry Pi 2/3/4 & 8GB or larger SD card (other equivalent SBCs could be used)
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Microsoft Kinect 360 (smaller point cloud, more manageable than Kinect One)
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Arduino Nano (or other AVR microcontroller you may have)
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HC-SR04 ultrasonic range finders x 3-8
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Generic USB GPS module
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Wemos D1 mini (or other ESP8266 dev board) x 2
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Wii Nunchuck controller (other joysticks could be used but these are cheap and nicely made)
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A USB power bank
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Generic XL4056 adjustable buck convertor PSUs x2
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Emergency battery isolator switch
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XT60 connector pairs x2
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Ubuntu 20.04 LTS on Raspberry Pi (to keep Pi 2/3 usable)
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Robot OS 1 LTS Noetic Ninjemys
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Arduino IDE 1.8.x (to build code for the ESP/Arduinos)
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Open Kinect (for Kinect 360 support)
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Gen 2 hoverboard hack firmware, specifically this fork by Pieter-Jan Buntinx
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OpenSCAD was used for designing the 3D printed parts and the source files are provided
First have a root around and see which of the parts you can find, price up the likely cost of what you don't and decide if you've got the time and budget to build a Crufty. Even with a lot of very basic parts needed a rover this size can get quite expensive.
The build is documented in a number of sections, all of which can be built kind of independently, but you should start with the chassis and attach things as you go.
The chassis is two pieces of wood/plywood about ?x? and some wood to separate the two pieces. That's it.
Good brushless motor controllers are expensive and the hoverboards should come with controllers. With the help of helpful hackers there is open source firmware for several different variants.
Cheap plentiful and powerful, this is how to mount the motors and connect them to the controllers.
A kinda point cloud for less than the cost of postage? What's not to like! Sadly we have to cut off the proprietary cable and make our own.
Don't own any RC gear? These make adequate joysticks for taking direct control of the ROVER.
The ubiquitous small board computer, just powerful enough to get started with ROS.
Old tech that still works. You can't always rely on the Kinect and this will help avoid many common obstacles.
These need to be flashed with open source hack firmware before they can be used.
This Arduino sketch turns a Wemos D1 mini (or any ESP8266 development board) into a co-ordinator that receives inputs from the Nunchuck controller and can manually control Crufty but also bridges control messages from the Raspberry Pi.
When you control Crufty with the Nunchuck it stops accepting messages from the Raspberry Pi but still feeds back sensor information.
This Arduino sketch turns a Wii Nunchuck controller and a Wemos D1 mini (or any ESP8266 development board) into a remote control for Crufty.
The small board computer running ROS and doing the smarter stuff that means Crufty isn't just a very bad RC car.