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.