Friday 19 August 2016

Controlling a junkbot with a Micro:bit


A new direction has been developed for the junkbot project (
http://junkbots.blogspot.co.uk/); previously Raspberry Pis have been used to control the junkbot’s movement (http://robotsandphysicalcomputing.blogspot.co.uk/2016/01/python-junkbot.html) – but what about the recently released Micro:Bits; can it be used to control a junkbot?

Matthew Hole, a student from Wrenn Academy, Northamptonshire ; has been investigating this idea whilst on a Nuffield Research Placement (http://www.nuffieldfoundation.org/nuffield-research-placements) working with Dr Scott Turner, University of Northampton. The project was to look into developing junkbots controlled using a Micro:bit and also to produce some materials for schools to use with or without outside assistance.






What is a Junkbot?
For this project, it is a moving ‘bot’ made from waste materials, combined with an electric motor and a programmable device (in this case a Micro:Bit) to control (or try) it. An example is shown above. More details on junkbots can be found at http://junkbots.blogspot.co.uk/


Approach used in the project.
A Micro:Bit was selected for two reasons. First, there was been a BBC supported project to give year 7 (or equivalent) students a Micro:bit (http://www.bbc.co.uk/programmes/articles/4hVG2Br1W1LKCmw8nSm9WnQ/the-bbc-micro-bit), so they are available in the schools. Secondly, Kitronik produce a motor driver board, and provide quite a bit of support for it, for the Micro:Bit (the latest version of the board can be found at https://www.kitronik.co.uk/5620-motor-driver-board-for-the-bbc-microbit-v2.html ). Using Micropython via the online editor https://www.microbit.co.uk to program the board and therefore the junkbot connected. The board with the Micro:Bit attached can be seen in the figure above carried on the junkbot.

An example piece of code is shown below:

from microbit import *

def startIt():
   pin8.write_digital(1)
   pin12.write_digital(0)
   pin0.write_digital(1)
   pin16.write_digital(0)    

def leftTurn(duration):
   pin8.write_digital(0)
   pin12.write_digital(1)
   sleep(duration)
   
def stopIt():
   pin8.write_digital(1)
   pin12.write_digital(1)
   sleep(2000)

while True:
   startIt()
   
   if button_a.is_pressed():
       leftTurn(100)
   
   if button_b.is_pressed():
       stopIt()



Suggested Resource List
  • Small Electric Motor
  • Kitronik Motor Board
  • Battery Pack
  • BBC Micro:bit
  • Pens
  • Junk (Can or Bottle)
  • Wires
  • Tape
  • Scissors
  • Broken Propeller or un-balanced load
  • Screw Driver


Related Links








All opinions in this blog are the Author's and should not in any way be seen as reflecting the views of any organisation the Author has any association with.

If you would like to know more about the Junkbots project contact scott.turner@northampton.ac.uk