Last Update: July 1, 2009

COMING EVENTS:

FRIDAY JULY 10 - IDEAS FOR KIDS’ WORKSHOPS. At the WEA “Cottage B” 223 Angas St Adelaide starting at 7:00pm Cliff Hignett will present some ideas for kids education along the lines of the PICAXE kits that we have presented several times to the kids at the Science Centre. These events give kids some hands-on experience with electronics that they don’t get elsewhere these days and have proved very popular with them.

Items coming up soon are: , GPS, MIDI, CD & DVD format standards.Python Programming, Aircraft Positioning System (ADSB), and Bluetooth.

SPECIAL ITEMS:

BENCHMARK TEST: A number of members who attended the AGM had tried at home the Richards’ benchmark test in Windows and Linux. The Python script can be obtained here and then run from the command line: “python richards.py”. Results were in the range 400 mS to 1100 mS (lowest numbers indicate fastest CPUs.) We expect to use Python for more projects during the year.

PAST EVENT REPORTS:

FRIDAY JUNE 12 - NEW COMPUTER HARDWARE STANDARDS. Adam Webb described and demonstrated a dazzling array of new computer hardware standards that included a quad-core Intel CPU fitted to a large, top-of-the-range motherboard with plenty of 16X PCI-e slots and running SATA hard drives configured in a raid array all housed in a large, well-ventilated, multi-fan cooled tower case overflowing with high-capacity power supplies. The nVidia video card covered several PCI-e slots, weighed a ton, and was connected to a wide-screen fast response LCD screen. This is the kind of system needed to run modern computer games or similar high demand computing taks. The audience was very impressed by the game Far Cry 2, a war game set in Africa, running on this hardware. It showed incredible detail and super-fast rendering that provided a degree of realism not seen and not even possible before this. You would do well to consider at least some of this hardware, if not for gaming, then for very high performance machines capable of connecting to a wide range of peripheral hardware and capable of highly intensive processing such as needed for video editing and processing, virtualization, and servers for busy networks.

FRIDAY MAY 8 - TURING MACHINES. David Tilbrooke gave a presentation on Turing Machines. Alan Turing was a leading British researcher who worked on deciphering Germany’s Enigma machines’ “uncrackable” coded messages during World War 2. He led a team that developed machines using electromechanical logic (mostly relays) to do the deciphering. After the war he continued his research into the development of early computers such as ACE that introduced programs stored in memory rather than using wired logic. In some of his early papers and presentations he introduced the idea of machines (now known as “Turing Machines” in memory of him) that, in spite of their simplicity and impractibility, can simulate any computer algorithm. While Alan Turing never saw a Turing Machine, modern computers can fairly readily simulate them. Check here and here for more.Here are a few useful book references and web site locations supplied by David for those who may be interested:

References:

• ‘Engines of Logic’, Martin Davis, W.W. Norton & Co New York, 2000.
• ‘Computability and Unsolvability’, Martin Davis, Dover Publications Inc., 1982.
• ‘The Undecidable’, Ed. Martin Davis, Dover Publications Inc., 2004.

Web Sites:

• www.turing.org.uk/turing/scrapbook/machine.html
• www.en.wikipedia.org/wiki/Mathematical_Logic
• www-groups.dcs.st-and.ac.uk/~history/HistTopics/Beginnings_of_set_theory.html
• www.turing.org.uk/turing/scrapbook/tmjava.html
  
• (This latter site has an active Turing Machine simulation.)

(There was NO APRIL MEETING because Easter fell on the 2nd Friday of April)

FRIDAY MARCH 13 - VIRTUALIZATION. Our Chairman, Andrew, presented and demoed Virtualization at our March meeting. This is a method of running one or more different operating systems from just one boot-up and operating them completely separately or, if desired, with various degrees of interaction with one another supervised by the virtual control software and/or hardware. Keeping overall control in this virtual environment is very attractive for testing, checking that updates actually work, the operation of servers, etc. wherever there is some risk of things going wrong or you are running an O/S and want a feature on another O/S without a full shutdown and reboot. Andrew uses virtualization to completely isolate and protect his company records from the Internet while other O/Ss on the same machine.are Internet connected. Virtualization puts some additional load on the processor, so the CPU needs to be fairly quick, and it uses a fair bit more memory than non-virtualized systems. Andrew used VMware running on an Apple laptop with Windows XP running virtually in one demo to be followed by another demo of a desktop PC running Xen as the control for a virtualized server system. With both virtual systems running and connected by a wireless link the situation got very complex and yet continued to operate happily. To get a glipse of the sort of things to expect from virtualization see the recently demoed Nokia N800 mobile phone (see video) installed with VMware that boots and then offers quick swaps between Windows CE and Google Android operating systems depending on what features you want?

FRIDAY FEBRUARY 13 - ANNUAL GENERAL MEETING. The election of officers for 2009 resulted in just one change to the committee - Adam replaces David.

The program for 2009 will add some items to the list left over from last year. Turing Machines, Aircraft Positioning System (ADSB) from last year and now add Python, Bluetooth, new hardware standards (PCI-e, SATA, HDMI), GPS, MIDI, CD & DVD format standards.

Other events that we hope to include are auctions that we haven’t held for some years of electronic equipment, show-and-tell nights where a number of you can briefly describe and/or demo items that would not fill a meeting by themselves. There is also Bluetooth hardware that is now down to $10 per dongle. See Bluetooth Special Interest Group for explanation of Bluetooth.

Rick demoed an LCD display from Aztronics that connects to his laptop using his interface cabling plus software he wrote in C for both Windows and Linux.

We viewed Peter’s set of flv videos showing electric cars being assembled and road tested in Sydney. The engines in standard model road cars were being replaced with electric motors just ahead of the gearbox together with lots of special high energy/weight ratio batteries (lithium-iron-polymer - note: it is “iron” and not “ion”), vacuum pumps (for the brakes), heaters/demisters, etc. Even those not very interested in electric cars got very interested in the vidoes. See here for one of the video series. Make sure you check out the others.

Lastly, if you have trouble viewing videos such as those electric car videos then try the Western Australian “live” Puppy Linux that is less than 100 MB download. Being a “live” version, it boots and runs without any disturbance to your hard drive and the real bonus is that it comes with all multi-media software installed and per-configured to display all video and photo formats in common use (ie. video works straight off without the need for a net connection, or downloads, or installation, or configuration - it just works!).

DECEMBER 5 - Virtualization was to be demoed, but will now be held during 2009. (Virtualization is where 2 or more operating systems can run on the same machine simultaneously.) Instead, the December meeting we had a preliminary look at Virtualization and Turing machines that will both be covered in the new year. We also had a look at those maths problems (above) and we had enough time for a Xmas drink in one of the nearby cafes in Hutt St.

NOVEMBER 14: On Friday November 14, Peter Rosenthal, Convenor of the SA PIC Users Group, gave a talk and demo of Vapour Phase Soldering that is now used extensively throughout the electronics’ industry to assemble printed circuit boards. Peter explained that the process was developed primarily for surface mounted (SMD) components. The method solves the problem of providing a uniform temperature sufficient to melt the solder on all soldered connections while simultaneously keeping the temperature as low as possible for as little time as possible to minimize the risk of damage to a board’s components. Very expensive and amazingly heavy liquids based on fluorides are used that are heated to their boiling point (phase change). The boards are immersed in the vapour above the liquid for just long enough for the solder to melt and then removed. Most components are usually held in place by a solder paste masked onto the printed circuit during preparation for soldering. Both leaded or lead-free solder can be used in the process, but with different fluoridated liquids because of the different solder melting points (210 C and 240 C). Peter used his video microscope that he developed for SMD work to show us what was happening. Peter also clearly showed us that the home constructor is able to construct electronic equipment using essentially commercial SMD methods.

OCTOBER 10 - SOLAR TECHNOLOGY: At our October meeting Paul and James from the Solar Shop presented, discussed and demonstrated some alternative energy products of the many sold at the Solar Shop, Payneham Road, St Peters.

We started with James showing us the very stylish Vectrix electric motor bike that costs about $14,000 to buy, but costs only about 1 cent/Km to run (compared to about 20 times that for an average car). It takes about 2 hours to fully charge the NiMH batteries from the mains that then gives you a range of over 100 Km with a top speed of 100 Km/h. It would be ideal for anyone as a commuter vehicle for getting to and from work, but maybe not for touring. Its near lack of noise, its very low maintenance (only one moving engine part - the brushless electric motor), easy handling on the road, low running cost, enough luggage space for average shopping trips and good looks makes it worth considering when petrol costs keep going up. Colin who took the Vectrix for a short run up and down Angas St was very impressed and had no difficulty making the transition from his normal petrol powered bike that he normally rides.

Next, Paul discussed 3 types of solar panels sold and installed by the Solar Shop - the Kaneka thin film, the BP poly-silicon, and the Sanyo hybrid that combines thin film and poly-silicon. All 3 arrays are normally grid-connected via converters (DC to 240 VAC). If you want complete independence from the mains by using, say, battery storage, a lot more cost and maintenance is involved. There is no “best type” since each has its own niche in the market depending on the situation. Probably the best economic choice, if you have plenty of roof space, is the Kaneka. The BP panels are more efficient, more compact and therefore use less roof space, but are the most expensive option. The Sanyo lies somewhere in between. Some costs to consider are the $8000 government rebate (subject to a means test), the 44 cents/KWh you get to supply power to the grid, the 18 cents/KWh you pay to consume from the grid, the approximate cost of $13,000 for a 16 panel 4.5 KWh/day (average) Kaneka array, and $25,000 approx for a 6 panel 4 KWh/day BP array. The Kaneka has a payback of about 1.8 years (ie. the time it takes to generate the energy it took to make it) that compares with 2.6 years for the BP array. George who lives near the Solar Shop and is very interested.

The last item that Paul discussed was the Skystream turbine that is ideal for windy locations. The turbine has 3 blades totalling 4 metres diameter, starts delivering power at 10 Km/h wind speed and reaches a maximum 1.6 KW output at 20 Km/h wind speeds. The turbine self-limits at speeds above 20 Km/h. Howard who lives at very windy Houghton is very interested to help supply his home “computer farm”.

With so much being said about means testing the Solar Panel subsidy and the damage it is likely to cause the solar power industry, well, the Solar Shop is flat out meeting demand and is still increasing staff.

SEPTEMBER 12 - iPHONE TALK & DEMO: On Friday September 12 Andrew Braund gave us a talk and demonstration of the recently released Apple iPhone. If you go to the Apple site you will see some promotional material on the iPhone, but it is nowhere near as impressive nor does it describe anywhere near as many of the features Andrew showed us during his talk. For example, the “spirit level” application seems to use the inbuilt accelerometers and/or position detectors to give precision level measurements, and there is the GPS feature that links to Google Earth over the ‘net and gives maps, satellite images and even street level photos if you want, that exceed anything you get on conventional car GPSs. There was a bit of discussion as to how the GPS location was being determined - was it with an inbuilt GPS module inside the tiny iPhone case or was it by triangulation from the 3G phone network or both? (Maybe someone can give us a credible answer?) Andrew did point out some problems. Instability in some applications causes lockups occasionally, and typing beyond a few words is really difficult. In fact, the best solution for a number of tasks is to do them on a PC and transfer them via Bluetooth or WiFi. But for portability the iPhone is an outstanding product. The iPhone represents “convergence” of separate hardware devices: 3G phone, SMS, Internet, email, office, GPS, games, music, camera, and video functions all combined into the one, light-weight, portable device. Thanks Andrew for such a timely and informative introduction to the iPhone with its huge range of features in such a well-engineered, tiny, good-looking package.

SUNDAY AUGUST 31 - PICAXE WORKSHOP: On Sunday August 31 we had another PICAXE Workshop for Science Centre kids and their parents. They bought kits supplied by Aztronics and assembled the demo projects shown here and here at the Workshop. The event was held at the Science Centre, old Hindmarsh Council Building, Milner St, Hindmarsh. The format was the same as last time - ie. minimum talk and maximum hands-on. There were 2 sessions on the day starting at noon and 2pm with a total of more than 40 kids participating. The kids and their parents were really pleased to see the 2 projects spring to life during each session. They easily completed both projects and had plenty of time to experiment with their own modifications to the kits. Every kid took home a working kit for more experiments and hopefully a much better appreciation of electronics and current electronic design practices. We wish to thank all the volunteer helpers from the Adelaide Microcontroller User Group, the South Australian PIC Users’ Group, and our group, the SA Microprocessor Group Inc who contributed to the success of the Workshop by assisting the kids with their kits. Many thanks to Rona and Craig at the Science Centre and Ben from Aztronics for organizing this event and to Pino, one of the dads, who took these photos [1], [2], [3], [4] .
AUGUST 8 MEETING was cancelled due to its coinciding with the Opening Ceremony of the 2008 Olympics.

JULY 11 MEETING - FLIGHT SIMULATOR: On Friday July 11 Adam Webb demonstrated the free, open source Flight Gear flight simulator available in either a single CD for minimum operation or as a multiple set of DVDs to provide a complete simulation of the entire world together with an enormous selection of aircraft that includes fighter aircraft, commercial airliners, executive jets, aerobatic bi-planes, helicopters, hang gliders, paragliders, the Wright Brothers’ historic aircraft, you name it, in an ever-increasing list. Scenery includes most of the world’s cities, airports, roads, railways, landmarks, rivers, mountain ranges, islands, and oceans. This simulator comes as a “live”, bootable Linux disc so that no hard drive installation is needed.

Adam took us for flights in the Concord (no longer possible now in the actual aircraft, of course), in a light plane, and even Santa’s sleigh. We took off from the Adelaide Airport and flew up and down the gulf and around Kangaroo Island. We also took flights from Heathrow and around London, around Paris with fly-bys of the Eiffel Tower, Notre Dame and the Arc de Triumph, around New York including the Hudson River, Manhattan, Long Island and (we think) Martha’s Vineyard - all in one evening!

Flight Gear is an excellent demonstration of the application of maths and programming skills to very practical uses in flight simulation, navigation, and 3D graphics in the complex and disparate environment of present day computer hardware.

There were some distortion artifacts evident, especially when the scenery was close to the vantage point. The artifacts suggest that the there are limitations either in the software rendering engine that converts the scenery data to a picture or the video card and its drivers. The clue is that as the scenery moves the artifact area effected on the screen doesn’t. Then, if the view is down from a high altitude it looks quite accurate and starts to get stranger as the vantage point gets close to the scenery. The root cause of that can be in the practical limitations to the trig tables where a more accurate calculation would take too long if you use calculated trig values, or alternatively, if you use very long pre-calculated look-up tables, it takes up too much memory. The scenery data has to be limited as well so the less points and/or the fewer number of significant digits you have for each data point then the more evident the artifacts become. Those things should improve as time goes by. It will be very interesting to revisit this software in future.

JUNE MEETING - DDS: On Friday June 13 we had a discussion on Direct Digital Synthesis (DDS) that is planned as a project to be used as a very precise local oscillator in a digital radio (DRM) receiver, a transmitter, or an item of test equipment. (DRM transmissions start in Australia January 2009.)
The 2 methods of precision frequency generation over a range of frequencies in general use - PLL and DDS - were described.

Because crystal oscillators are so vital to almost all computers, precision electronic instruments, radio receivers/transmitters, mobile phones, GPSs, TVs, set top boxes, DVD, CD, MP3 players, electronic clocks and watches, then these were discussed in some detail. Terms like X, Y, AT, BT cuts, temperature stability, overtoning, twinning, grinding, etching, edge bevelling, flexure, shear, FT243, DC-11, K, mini-K, and series and parallel resonance were explained. Some circuits such as Colpitts, Hartley, Chow, etc were described. Some practical demos such as using a micrometer to determine a crystal’s frequency and a DDS device and its software were included.

MAY 9 MEETING - FUEL CELLS. At the May meeting David Tilbrooke, whose career as an industrial chemist embraced industrial process development, museum conservation, forensics and work with Artlabs, described the history, structure and chemistry of various chemical cells such as the Baghdad Battery (c.250BC), Leclanche, Clarke and Grove cells that eventually led to the discovery of fuel cells in the mid-1800s. The fuel cells David described rely on combining hydrogen and oxygen to produce electricity and water. The cells themselves consist of membranes, electrolytes and catalysts together with a continuous supply of hydrogen and oxygen. Once established, fuel cells continue to produce electricity as long as they are continuously supplied with hydrogen and oxygen which is the big advantage they have over primary and secondary cells. Some disadvantages of fuel cells are that some operate at very high temperatures, some use dangerous and often toxic chemicals, and some components are expensive such as platinum. Nevertheless, some cell types do look like being part of the solution to providing an alternative to our rapidly depleting fossil fuels for power generation and transportation - although an abundant supply of hydrogen has yet to be found.

David’s talk stimulated a lot of discussion, particularly relating to some side issues raised such as carbon dioxide geo-sequestration and his forensic work. Maybe we can get David to tell us about his forensic work at some future meeting.

APRIL 11 MEETING: Peter Reed explained the Capacitor Paradox that was raised at the February meeting and caused some controversy. The paradox is that it can be easily shown by experiment that if a charged capacitor is switched in parallel with an uncharged capacitor then the sum of the energy stored by the two capacitors is significantly less than was initially stored by the charged capacitor. Peter showed that the “lost” energy is not lost at all, but is dissipated as heat and electro-magnetic radiation (radio interference). He also showed that combining electronics with inductors in suitable switching circuits placed between the capacitors can almost completely eliminate any energy loss.

For more light reading on the Capacitor Paradox, Dr Pudney, Uni SA, has supplied some links:

http://www.hep.princeton.edu/~mcdonald/examples/twocaps.pdf

http://www.physicsforums.com/showthread.php?p=823340

There was also some discussion on a DDS VFO project that could be the basis of digital receivers when digital radio is launched on the AM, HF, and FM bands in Australia on January 1, 2009.

ELECTRIC CARS - TALK, DEMO. On Friday March 14 starting at 7:00pm at the WEA “Cottage” at 223 Angas St Adelaide, Dr Peter Pudney who has been heavily involved with the Darwin-Adelaide Solar Car Races since their beginning and more recently with “Trev”, Uni SA’s electric car, and to a lesser extent, an involvement with the recently launched Adelaide City Council’s electric bus, “Tindo”, will talk to us about these items. The talk will concentrate primarily on Trev. (Dr Pudney has spoken to us about Solar Cars previously.) A special feature of the evening will be a demo of an electric car using super-capacitor energy storage. Those of you at the last meeting will remember the spirited discussion on the “capacitor paradox” where the energy in a charged capacitor is used to charge another uncharged capacitor resulting in far less total energy afterwards. This apparent violation of the conservation of energy will most likely come up again in connection with energy storage in electric cars.

2008 MEETING PROGRAM: A number of members at our AGM suggested or volunteered to talk on a range of subjects during this year.

So far, we have: Fuel Cells (David T), VoIP PBX (Col H), Capacitor Paradox (Peter R), Virtualization (Andrew B), Heart Monitor (Eric P), Flight Gear flight simulator (Adam W), Turing Machine (David T), Aircraft Positioning System (Mark S to arrange). Many thanks to those who have volunteered. We would also like volunteers to have a look into Python, MIDI, Go, Making Live CDs, and Sim City (source code now available), or any other suitable subjects for possible inclusion in this year’s program.

This web site now has MIRRORS at http://samg.yi.org and http://samg.supremeit.com