Controlling junk with LEGO

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 :





For more information on how this was done go to: http://legojunkbots.weebly.com/uploads/3/7/2/2/37227791/nuffield_nxt_mindstorms.docx or http://legojunkbots.weebly.com/

Idea Two

Is to do a similar approach as idea one but keep the motor and broken propeller combination but control the motors via a Raspberry Pi. This is discussed in another post http://robotsandphysicalcomputing.blogspot.co.uk/2015/07/raspberry-pi-controlled-robot-from-junk.html

Details of the work will be published on the Junkbots Blog (htttp://junkbots.blogspot.co.uk/ ) as the project progresses.

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.

Robot Software

In the previous blog posts for this 'series' "It is a good time...." 

• Post 1 looked at the hardware unpinning some of this positive rise in robots;
• Post 2 looked at social robots;
• Post 3 looked at a collection of small robots;
• Post 4 looked at further examples of small robots

Robots, such as the forthcoming Buddy and JIBO, will be based some established open sourceand other technologies. Jibo will be based around various technologies including Electron and JavaScript (for more details see: http://blog.jibo.com/2015/07/29/jibo-making-development-readily-accessible-to-all-developers/). Buddy is expected to be developed around tools for Unity3d, Arduino and OpenCV, and support Python, C++, C#, Java and JavaScript (for more details see http://www.roboticstrends.com/article/customize_your_buddy_companion_robot_with_this_software_development_kit). This post continues with some of the software being used with the smaller robots. 

A number of these robots are being programmed via Scratch or Scratch-like environments for example the OhBot (http://ohbot.weebly.com/) or Crumblebot (http://robotsandphysicalcomputing.blogspot.co.uk/2015/07/edge-following-crumblebot.html). Arduino based systems, discussed in Post 1, form the basis of a relatively large number of robots. Some other ways are discussed below.  



LeJOS
LeJOS (http://www.lejos.org/index.php) is an alternative way to program the LEGO Mindstorms Robotic Systems including the oldest RCX to the latest EV3. What it does is allow the robots to be programmed in Java by putting a small virtual machine on the controller/Brick. 

Some examples of it in use or being discussed can be found at:

• Robots and Neural Networks
• Sentry robot project
• LeJOS based books
• Robotics within the Teaching of Problem-Solving.

A relate tool that use LeJOS as one of its underpinning technologies is Enchanting. A Scratch-like way to program LEGO robot based around Mindstorm NXT and EV3. For more details on this go to: http://enchanting.robotclub.ab.ca/tiki-index.php



Tickle

Tickle (https://tickleapp.com/en-us/) is one of my favourite of the physiclal computing programming tools at the moment. It is designed for program a quite range of devices using a 'Blockly-like' graphical programming approach. The Sphero range of robots and some of the Parrot Drone are supported.

When  I recently bought a Parrot Rolling Spider Mini-drone, I used the Tickle App (https://tickleapp.com/en-us/)  to control it. This was the first time I have actual programmed something that flies; the fact you are controlling  something you able to move in all directions is very engaging.

On the left is an example used; essentially lift off, repeatedly move forward, turn and in the end land.

As well as drones, the Sphero robots can be controlled using Tickle (that is how I first came across it). This does also include the entertaining and popular Sphero Star Wars BB-8. Which is well worth a play, if you get an opportunity. Dash and Dot (see http://robotsandphysicalcomputing.blogspot.co.uk/2015/07/cutest-computational-thinking-in-world.html for more details)  are also controllable through Tickle was well. 


Also a number of devices such as Punch Through Design's Arduino-based LightBlue Bean (https://punchthrough.com/bean-teaser), a Bluetooth Low Energy (BLE) microcontroller are supported- I have get to play with this one though.

I like the Tickle App because of its easy of use but mainly for the company's expansion of the range of devices supported.




Feedback
Please add comments with other software choices.



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. The author does not and can not take responsible for any harm cause by the software discussed - if you are unsure do not use the software.

It is a good time to play with robots

In the previous blog posts for this 'series' "It is a good time...." 

• Post 1 looked at the hardware unpinning some of this positive rise in robots;
• Post 2 looked at social robots;
• Post 3 looked at a collection of small robots;

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).

Related Link

Junkbot Raspberry Pi: 1 ScratchGPIO 

Junkbot Raspberry Pi: 2 Raspberry Pi Junkbot in action

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.

Lego Mindstorms – Sentry Robots

Sameer Kumar Shrestha, Northampton

The report presents the dissertation on title Prototype of Sentry Robots for Advanced Security which includes the use of LEGO robots showing interaction between each other with the help of wireless communication medium in Bluetooth. The purpose of the work is to build a communication between multiple LEGO robots using the wireless technology. For this task, the NXT version of LEGO Mindstorms has been selected. It is because there is need of complex communication which is possible through wireless medium such as Bluetooth and also a suitable processing device for the proposed task which is present in the LEGO Mindstorms NXT. The report has also focused on the background information about the NXT system and its great flexibility with LeJOS NXJ as the programming platform. The outcome is the implementation of developed work with the use LEGO Mindstorms NXT and the LeJOS NXJ as programming platform. The task was approached with one LEGO NXT robot maintaining the distance between the object in the environment and searching the object by rotating in case of lost. After the completion of the first task, the next task was to study the communication behavior of multiple robots communicating with each other to fulfill the same job. For this, three NXT robots were taken and programmed in such a way that they form the shape of triangle and keep tracking the object.  All three of them send and wait for the information from each other and process this information to produce a suitable output, i.e. to respond to the action from each other. Thus, it was found that the implementation of several processes to multiple LEGO based communication had faults, due to the technical hitches with the communication technology and limitations of the NXT systems.

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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.