building and hacking Robots:

lost in (Maker) space  

Solve a maze:  The new Lost in Space series on Netflix is the inspiration for a "Rescue the Robinsons" maze competition. This entry involves a scratch-built robot, the purchase of a kit to assemble, or the purchase of a ready-made pre-assembled robot. The robot MUST be autonomous...self-contained with NO remote control permitted.

Fight a Sumo battle: Sumo robot competitions have been prevalent in Japan, with the first competition being held in 1989 with only 33 robots, by 2001, the number was over 4,000. This entry involves a scratch-built robot, as seen here on the right, or the purchase of a kit to assemble, or the purchase of a ready-made pre-assembled robot.

	MegaBot ring Diameter: 154 cm Height: 5 cm Edge: 5 cm black Center: white
	MiniBot ring Diameter: 77 cm Height: 2.5cm Edge: 2.5 cm black Centre: white

• Great introduction to robotics and coding for Primary / Intermediate students
• Works straight out of the box, (once batteries inserted); no programming needed to see results!
• Can be programmed by bar codes provided, for immediate obstacle avoidance, sumo, etc.
• EdBlocks programming interface simple to use for beginners - no language to learn!
• EdPy text-based programming for more advanced use to learn coding skills
• Cheap, easy to use universal programming lead that plugs in to any headphone jack on any device

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Construction ideas - Arduino or PICAXE robot  (Sumo or Maze entry)

Here again it adds a lot of appeal to have a fully "dressed" robot. Rather than letting people see the bare circuitry and gears, why not make a body costume to make your robot look more interesting and appealing?

You could recycle parts from an old analogue TV like I did here in the video below:


OP1 is a PICAXE-based robot with a L239D motor controller and a Bluetooth module. He operates on 8 C-size cells (12 volts DC).

OP1 senses the environment for temperatue and static electricity, sending the data back to my smartphone for graphing. I can also take control of OP1 to drive the robot remotely. There is a MP3 player module to produce sound effects. On the front is an ultrasonic range finder module, an aid to avoiding obstacles when OP1 autonomously explores his surroundings.


Suppliers of kits and parts; There are a number of suppliers of PICAXE and Arduino kits and parts. Try Mindkits or Jaycar or Surplustronics.

I have recently seen Arduino Smart Car kits at www.dx.com  who also provide motor controllers, bluetooth modules, ultrasonic range finders, etc, often with free delivery.  I have found them very reliable, but some parts take a few weeks to arrive, depending on availablility.

	'Brains' - Arduino board The Arduino Smart Car kit is a great dea from DX.com. AND you can substitute easily a simpler breadboard with a PICAXE 18M2 chip to replace the Arduino board and sensor board. Keep the Arduino and sensor board for another time! Add a bluetooth module (see further below) for just US$4 and you have your own OP1 robot! Arduino Smart Car link Arduino main website
	'Brains' - Picaxe chip Electroflash link Electroflash has breadboards (just push in components, no soldering)  and programme download cables at good prices too. Picaxe chips (try the 08M2, 14M2 or 18M2) are VERY easy to programme in BASIC with free software, much simpler than the Arduino. Picaxe main website
	'Brains' - BBC  Micro:bit board Learning Developments link Micro:bit robots also need the Micro:bit controller as well (link here) Easy to programme using free software. This is a line follower. Micro:bit main website
	Wheel kits Left; DC drive gear motor and tyre DX.com link Right; Tamiya dual gearbox Mindkits.co.nz link
	Tamiya dual gearbox Mounted on MDF board cut to size. If the wheels are pushed tightly inwards on axles this just fits in the 10cm size limit for the MiniBot class
	Battery pack; 3 cell AA, 4.5 volts Your robot could use just two AA cells for a lighter weight battery pack running at 3 volts. I place the pack on the MDF, then attached the 'brains' of the robot, the PICAXE breadboard, on top.  A little hot glue can help hold things together if just solving a maze. Using 3V or 4.5V depends on the motors you are using. Battery pack link
	Breadboard with PICAXE 18M2 You can use an 08M2 chip or 14M2 chip to drive the motors via transistors - PICAXE, breadboard, cable link.   I use the USB adapter and serial cable  for programming. I prefer to use one of the motor drive controller boards below; very cheap, reliable and simple to control. I have provided a test code below for you to learn from.
	L239N motor controller board. This sits on top of the battery pack, breadboard nearby for connection of signal wires. Consider an extra battery pack to power the motors seperately from the PICAXE, definately for the larger MegaBot sumo robots. See further below for a H-bridge  circuit from Andrew Hornblow for a  simple maze robot without the motor controller.
	L239N motor controller The controller on the left; Arduino compatible controller link I use the controller on the right; Keyestudio motor controller link Information sheet here I have provide example code for a PICAXE 14M2 here; Bluetooth motor controller test.bas
	H-bridge using transistors and blue and green LEDs. Requires 4.5 volts. Click on the thumbnails to see a larger image. H-bridge circuit from Andrew Hornblow. Winston infra-red controlled robot built by Michael Fenton
	Ultrasonic range finder Range finder link This uses high frequency sound, like echo location used by bats, to sense how far away an object is. Information sheet here I have provided example code for a PICAXE 14M2 here; Range finder.bas
	Infra-red obstacle detector IR obstacle sensor link Infra-red line sensor Get 2 of these and position a distance apart slightly more than the thickness of the line being followed. IR line sensor link
	Bluetooth module Bluetooth module link Use your smart phone to control your robot AND receive data from sensors on the robot. Information sheet here Bluetooth RS232 TTL guide I have provide example code for a PICAXE 14M2 here; Bluetooth motor controller test.bas
Download the Android APK here	If you want to send or receive data to and from your robot via bluetooth just like OP1, I use a phone app; Keuwlsoft Bluetooth Electronics You can drag and drop your own buttons, joystick, graphs and meters to make a custom display screen for your awesome robot! I have made an instruction sheet here; Bluetooth Electronics guide

Robot Gallery for ideas...small to VERY LARGE

Edison V2 robot MiniBot class Available from Mindkits.co.nz Simple Bar Codes for Sumo and Line following link Lesson plans link for coding in EdBlocks, Edware, or EdPy.
Edison V2 robot - B9 from Lost in Space MiniBot class PICAXE code to flash the lights is included here; LEGO-B9-robot.bas I have deliberately made the code  in long form for  novice or beginner students to read. How could you rewrite the code to be shorter and more efficient?
CASI MegaBot class PICAXE 08M-based Casio Graphics Calculator controlled robot, CASI is part of the RIGEL project, used in my Calculus and Physics classes. Find out more about building a PICAXE games app link and  home-made science and maths equipment here for student-led problem-based learning in STEM.
Cybot MegaBot class With a slight modifiction (removing back and front  rubber bumpers), Cybot is a good example of design and 'dressing up' the bare mechanics to make a more pleasant looking robot.
Arduino two wheel smart car MegaBot class Also order two line sensors if you want to have a line follower. Add a body shell and face to complete it! Add a low-cost bluetooth module for full OP1 functionality. Order the kit or sensor modules from www.dx.com
Robo:bit Megabot class Also order the Mico:bit controller itself, and two line sensors if you want to have a line follower. Add a body shell and face to complete it! Order kit or sensor modules from Learning Developments
OP1 PICAXE 14M robot, MegaBot class With a slight modification (reposition the wheels to underneath the body) OP1 is a MegaBot, a good example of recycling to make a robot. The body shell is from an old TV / radio and  hides the circuitry of a modified two wheeled smart car (above).  I used a PICAXE chip to replace the Arduino board. Add a MP3 player module for sound effects.
Dalek Full-size replica..too big for competitions but a very nice STEM project to build! Arduino or PICAXE controlled. Students can sit inside and operate the Dalek. Runs on 6 C-size cells. Dome lights flash in time with voice modulator, gun fires with sound effect. Find out how to build this from our sister site; Dalek building page on Nexus Research Group site

Robots in movies and TV

Want to gain more digital technology skills? Make a movie using your robots! See the Dalek battle a bear in our 48 hour film entry "Collision course" by Jampot Productions in Taranaki, winner of two local awards including Audience Favourite.

Original fun experiments & technology to build for authentic maths and science investigations for all ages;

visit      www.NexusResearchGroup.com