Up to this point the junk bot building has largely being about building a moving (or drawing) 'bot' moved by vibration - limited control, but fun. A Nuffield funded bursary student, Hayden Tetley, has being working within staff from the University of Northampton on whether LEGO 8547: Mindstorms NXT 2.0: Robot
or Raspberry Pi based solutions can be incorporated with the bot to add some control of the movement (still by vibration). Idea One Is to add a LEGO NXT brick, to move a junkbot similar.The motor and broken propeller combination in the earlier junkbots is replaced with the NXT brick and LEGO motor. A good potential feature is it a self-contained unit with power and control together, as well as being potentially fairly simple to set-up. This is the focus of this post. Here are some videos showing idea one in action using LEGO motors, brick and the software that comes with the LEGO 8547: Mindstorms NXT 2.0: Robot
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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.
This post continues with small robot idea a bit more, looking at some of the other robots I have been fortunate to be able to play with. The opinions are from a personal point of view of playing with them, but comments are very welcome. Kbots
The kilobots (http://www.k-team.com/mobile-robotics-products/kilobot)were designed to be relatively low-cost devices specifically designed for work on swarm/collective intelligence experiments. Developed at Harvard University as a scalable system to program groups of robots (now into the thousands) (http://www.eecs.harvard.edu/ssr/projects/progSA/kilobot.html). Individually these are quite simple units, they move by vibration. The real advantage, in my opinion, of the system though is you can program lots of them in one go - scalability is therefore not that difficult. The video below is from a colleague's work who used these during his MSc work on collective intelligence. To read more on this go to: http://robotsandphysicalcomputing.blogspot.co.uk/2015/07/narinders-swarm-robots.html Scratch Robot Arm
It is not physical but CBiS Education have release a free robot arm simulator for Scratch. Downloadable from their site here - it includes a Scratch project, guidance on Scratch along with an exercises in using the robot arm simulation and an exercise with teacher's guidance. CBiS produce a physical version of this, details are available at http://www.cbinfosystems.com/cardboard2code_module3.aspx
What I like about this is, apart from being free, is it is Scratch-based and it does simulate physical problems such as the need to co ordinate multiple parts of the arm often to achieve a task.
LEGO Where do I start with these? LEGO have done a great deal to get a lot of people interested in, and provided a route into robotics. Whether though the 1980 - 1990s with the Technics range or when they released their Mindstorms (I can see another post coming on here). My interest has been focused for the last ten years or so on their use in teaching problem-solving and Java Programming to undergraduates (read more here). The combination of either the earlier RCX or NXT ranges with the incredible LeJOS (http://www.lejos.org/) provides an accessible and easy (I think easy some times) way to link robots and undergraduate programming in Java.
I will expand on these a little more in a post of dedicated to LEGO . Junkbots Another shameless plug, Junkbots, was a project that started close eight years ago concerned with linking computing, engineering and environmental science in activities for use in schools. The core was to use and look at waste and how could we combined waste materials and robotics to either build a 'bot' out of junk or used in combination with robotics (initially based around LEGO) to clear small junk piles (a few light materials - nuts, bolts). To read more on this project go to http://junkbots.blogspot.com/ . The area that quickly became the focus was the building 'bots' out of junk (session plan: http://junkbots.blogspot.co.uk/2015/08/junkbot-session-overview.html). This evolved into the building one of these but controlled via a raspberry Pi. This is the idea discussed below. The card chosen to control the motors was the 4Tronix PiRoCon card. It fits straight onto the Pi through the GPIO - no extra cables needed. ScratchGPIO has it as an addon so it makes programming it even easier (see http://cymplecy.wordpress.com/2013/10/31/pirocon-from-4tronix/). It is quite easy plug the board directly on to the GPIO connector of the Raspberry Pi (4tronix provide some advice in section 15 of http://4tronix.co.uk/blog/?p=22 on mounting the board). The only other changes I needed to make because I wasn't powering the motors through the DC input I had to change the jumper settings next to Vin Connector (see http://4tronix.co.uk/blog/?p=41 for layout) to reflect this.
Now for the fun bit getting the whole thing to draw (see Figure 1 and the video at the end)!
The junkbot itself is made up of a drinks can, three supports ( LEGO was used here but it equally could be straws, sticks), a pen/pencil, and a motor and broken propeller combination to create an unbalanced motor. With the Raspberry Pi off, the the motor's wires are connected to the controller card at the connections for MotorA and the battery is also connected. Turn the Pi on and run ScratchGPIO5plus.
Figure 2
Figure 3
Figure 4
The first task is to make the variables AddOn (which will be used to tell the program we are using the PiRoCon card) and MotorA for the motor (see Figure 3). In Figure 4 the program can be seen, essentially the left and right key spin the junkbot clockwise or anticlockwise by setting the Motor to either +ve or -ve values from 0 to 100. The space bar is used to stop the motor. As it moves because one of the supports is a pen it draws. See the video below to watch it draw a squiggly line - control is still a challenge. The bot was developed by Hayden Tetley and Scott Turner. Hayden's time was paid for through the Nuffield Research Placements Scheme (http://www.nuffieldfoundation.org/nuffield-research-placements).
In the next post in the series I want to look at the software a bit more.
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.
or Raspberry Pi based solutions can be incorporated with the bot to add some control of the movement (still by vibration).
