Christchurch Robotics Meeting: Wednesday 16th April 2008
The second meeting of the year attracted about 20 people (sorry I forgot to count and only 9 signed in). There was a nice age range from 12 upwards, some new faces and some coming by recommendation. The gold coin collection netted $15, thanks for your donations, they go to Science Alive and are very much appreciated. With folks saying they will be along next time we seem to be growing our number of regulars.
Attending Robots and Topics
Mike Pearce kindly donated lots of spare components to the group and many boxes were trawled through and parts taken away for building into robots. There is still heaps left so I’ll bring what is left to the next meeting. Thanks Mike for your generosity.
We had a talk from 12 year old Tayler about the Lego RCX walking Robot that he built and brought along. Thanks for bringing it along Tayler and we hope to see you and your family again.
Carl brought along a propeller ADC circuit with 3 ADCs almost running on a single board. The ADC uses the propeller chip in Sigma-Delta mode and just four passive components. We didn’t fix it on the night but hopefully we’ll get it going soon, either with shorter leads or maybe a software fix.
I (Richard Jones) brought along the propeller proto board built onto a two wheel plus two castor platform with motor driver for micro mouse maze solving. I gave an introduction to micromouse based on info from Peter Harrison site here: http://micromouse.cannock.ac.uk/ and showed the Python micromouse simulation running on Mac OSX.
Andrew McDougal has very kindly returned the Parallax Propeller proto board that he won a couple of meetings back. It is available to the first person to reply on condition that it returns built into a robot or doing something of relevance to robotics.
Also I have a couple of Microsoft optical mice with faulty buttons available for robot building. Just email me via the list if you would like one. These are the single chip sensor mice that do USB and PS2. I don’t think you can use this chip to get the picture or quadrature signals like you could with the early optical mice.
A wooden robot was also bright along but I didn’t get to meet him until he was going through the door.
Thanks to everyone for coming and for joining in the lively discussions.
Next Meeting
Our next meeting is on Wednesday 18th June 2008 when we will have our usual show and tell format followed by a talk from Hanno about interfacing to devices that he has on the Dancebot (accelerometer, gyro, compass, tv camera etc). Do check out our site http://www.kiwibots.org just in case of any late changes or additions.
Last Updated ( Monday, 23 June 2008 )
Meeting Report Wed 18th June 2008
Written by RichardJones
Thursday, 19 June 2008
Christchurch Robotics Meeting: Wednesday 18th June 2008
The third meeting of the year attracted 25 people. It is with much sadness that I have to report that Sean Anderson one of our regulars passed away recently. Our sympathy goes out to Sean's family.
We had two excellent presentations with Robots from two of our younger members, and also presentations from myself and Hanno (somewhat older guys). The gold coin collection netted $28.30, thanks for your donations, they go to Science Alive and are very much appreciated. With folks saying they will be along next time we seem to be growing our number of regulars.
Attending Robots and Topics (in order of appearance)
Joshua brought along his Dad and a fully functional scorpion robot with attitude called ' Spike' and made from Lego NXT. My description will hardly do justice to the presentation from Joshua, but this is what I think it did. Using a combination of ultrasonic, infra red and touch sensors with three control loops the scorpion advances towards its prey and stops when almost within striking range. If the prey (thankfully mimicked by Hanno) advances towards the scorpion it rapidly unfolds its stinger and strikes the prey. The stinger then retracts and the prey retreats if it knows what is good for it. Joshua went on to explain very clearly the graphical programming language and how to connect the robot to the PC for programming.
Tayler brought along his Dad and his sister, a tracked line following robot and a trail for it to follow. The Robot followed its track well and Tayler gave us a nice explanation of how he put it together and set about programming it. There seemed to be a consensus that at the next meeting we would hold a line following competition. Just to be fair I think that Adults should race in a separate category so that we don’t get too badly beaten! Prizes to be decided, I’m hoping for chocolate fish or sugar mice. I produced a low cost line follower design a while ago and the design files can be found here. Some of the files are copyright and I've asked the IET for permission to publish them. Meanwhile the information is not hosted on our kiwibots site
I showed a an ATMega8 CPU bought for $6.70 from South Island Components hooked up to an infra red wall sensor prototype and a laptop for software development and programming. The AVR hosted a boot loader to allow the AVR to be programmed via a USB serial port adapter. The laptop computer hosted the avr-gcc cross compler and Eclipse IDE with C Developer Tools (CDT) loaded. All these tools are open source and free. Although I made a PCB to host the AVR I’ve come to the conclusion that veroboard would be almost as good.
Hanno started his presentation by sharing photos from his recent trip to California. He and his DanceBot attended Yuri’s night, were part of the Parallax booth at the Embedded System Conference, and visited Parallax Headquarters. He then talked about the upcoming USB Oscilloscope from Parallax built on his ViewPort software. He showed us the new graphical interface of ViewPort featuring 4 views: DSO, LSA, combined DSO/LSA, and a view showing multiple instruments including spectrum analyser and xy mode. Lastly he used ViewPort to show the bit-stream communication and decoded measurements from the sensors connected to his DanceBot: Quadrature Encoder to track robot position, compass, ultrasound ping sensor to measure distance, accelerometer and gyro fused with a kalman filter to sense tilt, and a npn transistor to measure temperature. (Thanks Hanno for this part of the report).
Thanks to everyone for coming and for joining in the lively discussions, and a special thanks to those who constructed and brought along robots.
Next Meeting
Our next meeting is on Wednesday 20th August 2008 when we will start with a line following competition then our usual show and tell format followed by a talk on a topic to be decided. Do join our mailing list if you would like to offer a talk on some subject. Ideally the talk will grow our knowledge and understanding of one or more topics in the mix of technologies and physics involved in Robotics. Be warned, in the absence of another offer I will present a system of hardware and software modules that I plan to apply to line following, tabletop challenge and Micromouse. Do check out our site http://www.kiwibots.org just in case of any late changes or additions.
Last Updated ( Tuesday, 24 June 2008 )
Tabletop Challenge
Written by Hanno
Tuesday, 06 November 2007
Table Top Challenge
The group has a tabletop challenge, and our founding member Andrew unashemedly adapted their idea to local conditions. The goal is to build a tabletop robot, that can drive around a Science Alive table without falling off the table, and locate a 2x2 inch box. Once it has found the box, it needs to push it down to one end of the table and into a shoebox. The eventual goal of this challenge is to get working robots, in the club, that could be used for 1 on 1 tabletop soccer.
The challenge has 3 phases:
Stay on the table without falling off while turned on and moving.
Locate the box on the table and push it off without falling off yourself.
Locate the box, and push it into a shoe box (goal) at one end.
