[chbot] What we did on Tue14th April2009...

[Richard Jones]

The evening was very well attended. We were pleased to welcome Kate Coleman
with parents and youngsters from http://cagcy.org.nz as well as many of our
regular attendees. The gold coin collection raised $82 for Science Alive
which was very much appreciated. Thanks to all who came, especially our
speakers John Wynyard and Charles Manning who put so much energy and
preparation into their presentations. Meetings are now held on 3rd Tuesday
of even numbered months. Next meeting will be on Tuesday June 16th 2009 in
the Science Alive Seminar Room. Offers of presentations and topics for our
next session most welcome. For those who were not able to make it, here is
a record of what we did (do let me know if it needs updating) ...

John Wynyard from Science Alive gave us an introduction to Robocup Junior
Rescue, Soccer, Dance and Theatre categories with live demonstrations of
robots performing rescue and soccer challenges. The Robocup web site is due
to be updated soon with new rules, application forms and venues. See:
http://www.robocupjunior.org.nz for more details. John has an .avi movie on
DVD available with scenes from the National Competition, this gives an idea
of the standard required to get to national level. Our regional competition
will be held at Selwyn House School on 9th August 2009. Stuart Whelan has
offered to coordinate individuals, not associated with a school entry, into
teams providing a venue, space, and technical assistance. Stuart may be
contacted by email here: robocup at somepointinthefuture.co.nz

Alex brought along a new NXT sumo robot that had a very neat spiked roller
to catch and pull the oponent off its wheels. It gave a very convincing
demo of pushing my robot, Gnasher, out of the Sumo ring. Thanks Alex for
bringing the robot and your Dad.

Peter showed more robots from the Robokits range including a tiny robot
from Polulu with very smooth line following action. Peter has a huge range
of NXT sensors in stock. See the whole lot at http://www.robokits.co.nz/

Matthew showed us an ingenious way to create a free running ball castor
from a ball bearing held captive in a wooden frame with a nut and bolt to
run in.

Timothy showed a line following robot made from Tamaya gearbox and wheels,
avr micro and light sensors with discrete H bridges. Timothy has plans to
get his robot maze solving, maybe it will be maze solving before mine.

Phil told us about creative/project/hacker/maker space in Christchurch
where you can meet like minded folks to discuss and make things. Sessions
are currently on Sunday afternoons and Wednesday evenings at the Canterbury
Innovation Incubator, 200 Armagh Street, Christchurch. see:
http://chchspace.nztech.org/ 

Charles Manning delivered a very practical introduction to making your own
sensors for Lego NXT. Everything from how to cope with crimping the strange
connectors, some really simple switch, and opto interfaces through to
active blocks to more than double the NXT sensor capability. You find
Charles slideshow here: http://embeddedjanitor.blogspot.com/ Charles
recommended a book that parallels much of his work:
http://www.extremenxt.com/books.htm

After the meeting Timothy asked me how my micromouse maze solving
simulation colour character display is implimented. The complete code can
be found here:
http://homepages.ihug.co.nz/~rjtp/Micromouse/Simulations/LinuxMouseSim.tar.gz
the display function is in file navigator.c Navigator_ShowMaze(  ).
Documentation on escape sequences can be found here:
http://en.wikipedia.org/wiki/ANSI_escape_code