User:Ian parker

A short biography- my technological journey- so far

"Practice does without theory; theory will not do without practice".

I started teaching at Wee Waa Central School, NSW in 1979. The previous year I bought a HP25 pocket calculator for over $100. It was programmable and of high engineering quality- and introduced me to the mindset. I read about the "personal computer" and decided that I would own one- I told my parents and they did not believe me. In 1981 bought an Exidy Sorcerer for $1200. A year later I bought a CP/M 300K Floppy Disk drive/controller, weighing in at several kilograms, to match for another $1200 (about 1/10 of a years salary), requiring me to also buy 16K RAM (not 16M, not 16G) as a set of DIL Chips for $300 and gingerly install them myself. This brought the system up to 32K RAM. It featured ROM-PACs - ie Plug-in ROM sets. They were housed in crudely altered 8-track cartridges. I bought a Wordprocessor ROM PAC and did my first wordprocessing using Wordstar like markup commands. Then I had to go out and buy a printer, an Epson MX-80 dot matrix printer, so I could print the documents I had written. Sound familiar..times have not changed, only the prices, capabilities and speed (of the underlying hardware and software, not people).

My next foray was to purchase a BBC Micro Model B. This was a superb machine in just about every respect. To this day, it too could hold its own in terms of engineering excellence. I used it as the basis of introducing a full scale Year 9/10 Computing course at Broken Hill High School- before Computing was a subject in schools. I had to write an approved course, and interestingly what I wrote was very close to the BOS course that appeared a few years later- even to the modular structure. About this time I also became interested in developing higher order thinking skills in students and how to make this more concrete (using the a flatbed plotter-to draw Fourier components of complex waveforms for Physics and small mobile robot LEGO buggy to demonstrate LOGO TURTLE like programming).

The course was progressive for its time, because I had included a study of robotics and artificial intelligence. To support this I developed some expertise in Prolog and built a controller for the LEGO Buggy that could be connected to the parallel printer port of a BBC machine connected across an ECONET network to another BBC machine. The student user could remotely control the buggy. I designed the system to allow students to do this. I had to, so that each student or group of up to three, could work on the code independently, and then send it to the machine connected to the controller/robot buggy to execute. It worked very well and was documented in Information Transfer (Journal of NSWCEG).

Some of this work is documented in professional journals of the day, international, national, state and regional conferences.

I also participated in the early Telememo e-mail trials around 1984. Two notable things to emerge from this were: co-ordinated collection and publication of temperature readings by students and schools within NSW and several other states. It predates similar attempts by at least 10 years. I also became a "match maker". Some of the girls in one of my Y10 computing classes (in those days roughly 50% were female) were able to become friends with some boys in Northern NSW via e-mail. The exchanges were very innocent compared to today's behaviour. Well, it turned out the boys were on a holiday to South Australia and the girls met up with them as the boys passed through Broken Hill. This pre-dates the modern "Internet" by at least 10 years.

Later I also owned a BBC Master 128K and an Archimedes 310 computer that contained the famed ARM CPU (before it was called that) found in almost every battery powered portable electronic device. I was so impressed with its in-line BASIC assembler, that I boldly wrote a Laplace transform module, for a Watford Digitiser I installed in it. I wrote that this processor and its instruction set should be studied by any student of computing, and that it was as elegant as any instruction set could be. I was proved right less than 20 years later. I published a paper on this in Information Transfer. The digitiser could digitise and rotate and resize a 512 K x 512K B/W image in realtime from a PAL video stream. What was remarkable about this was that the digitiser did not contain a GPU. All processing was done by the ARM CPU using very fast in-line code. This was at least 10 years ahead of what was to follow on other platforms. Some of the early fast GPUs were actually embedded ARM chips.

It saddened me to see the writing on the wall for the ARM platform as a workstation.

At one time I used DOS to teach Office Software( Wordprocessing, Database, Spreadsheets) at the local TAFE in the evening, BBC Micros in year 9/10 classes during the day, and at home a Macintosh. Believe me it was mind numbing stuff trying to understand/remember the 3 vastly different user interfaces. Anyone who complains about the differences between Mac OS X and Windows has serious credibility issues.

Before I left Broken Hill I bought a Mac 512K after having seen a fellow teacher's Mac 128K. It was an interesting experience lugging it around in a large bright red padded container. Everyone who saw it wanted to see it work. It would be some time before I bought an ImageWriter for it. I also bought a Koala Digitiser- very crude by today's standards but it showed potential- and was a very poor imitation of the Archimedes digitiser.

Just after my move to Ulladulla, I was asked to do a presentation on technology, to the staff. While it was well received, you could see that some of my ideas and what I was trying to achieve were well in advance of local understanding. My next idea was to purchase a newly released Powerbook 140. So I did, and promptly went on a 6 month holiday in Mauritius, Africa and India (without the Powerbook 140). While in Africa I went to a safari (real!) trade show. A person there had a PB140 but did not know how to even turn it on. So I did a few things to demo. He was very pleased and gave me a copy of his CD-ROM called SVINGA, he was working on-produced using a Macintosh. This was the first time I had seen a CD-ROM- when blanks were worth upwards of $50 a piece, and drives were over $1000.

Later I developed some science worksheets that allowed me to use the PB140 (laptop) in class. I would take it in, get students to take turns using it out the front, under my supervision. We used the word-processor, and spreadsheet from AppleWorks. Interestingly the focus was on energy and waste in the home-sources and minimising both. This predates similar widespread efforts by at least 10 years.

I also was able to e-mail communicate with a student at Gallaudet University in the US because I had a deaf student (being supported by a deaf Aide! who could speak remarkably well, and sign and lip-read remarkably well). Through this I became aware of the "deaf culture". This was using a 4800 B dial-up connection that cost $10 per minute. I also became aware of bulletin boards- and downloading software.

Soon after in 1995, I was appointed to be the last Riverina Region Computer Education and Technology Consultant. It lasted for less than a year. I became aware of work being done by universities and this new thing called the Internet, and more importantly the World Wide Web. I worked with some people at the local university in Wagga Wagga, eventually gaining an account that allowed me to access "the web". Soon after, I found software on the internet, including Netscape Navigator 1.0 and WebStar on a Macintosh. I managed to set up a web server located at the school of education, for local schools to use- for free. But few were interested in 1995, probably more so since they had little idea of what a web server was, what it does, how to make web pages- and so it was with me. Very few outside of universities had ever seen a web page. You did all the markup using text editors- after reading one of the few publications or "user notes" giving examples. Graphics were difficult because there were few editor/composers.

It was at this time that the NSW Education Dept "30 hour program", better known as TILT swung into operation. I was in the room the moment it was named. About 25 people were present, and each had to provide a name. Mine was "Going Global" - which did not get up, but the term has been used regularly since then in other contexts. A notable result was that we were able to set up a video conference between teacher participants in Riverina trialling TILT materials as they were written, and the TILT team in Sydney for feedback and evaluation purposes. It was interesting setting it up because nobody had any idea of what was going to happen- for 50 minutes! (and for the Wagga Wagga participants, after a full day's work, was voluntary, with some to travel for a couple of hours to get home, but they went along).

I even had to write the script (some questions for each side to ask) and encourage interaction. At Wagga we had about 25 people crammed into a room. In Sydney there were, from memory, about 6 people- arranged like an interview panel. The meeting went well and everyone was impressed. This predates more common use of video conference events between teachers, in schools by at least 10 years. The motivation for me was threefold: did not need to travel to Sydney, dramatic reduction of cost, it was an interesting way for more direct communication to take place. Things really have not changed, save for the imperative.

After that stint. I moved to Batemans Bay, to support schools grapple with the introduction of technology, such as the Satellite Receivers (a few of which very quickly rusted because they were regularly sprayed by the ocean) and dramatic upgrades to Internet access. One of the most notable results was the required upgrade of local telephone exchanges (in some cases from equipment pre-dating the 1960's). This meant that rural subscribers could enjoy better telephone services, and in some cases Internet Services. Schools were beginning to grapple with local networking issues - some fared better than others. Those that tried to "do it on the cheap" sowed the seeds of future difficulties. Similarly those that had little understanding of the physical limitations of the equipment they were installing also sowed the seeds of future difficulties. It was difficult to explain why video distribution to several machines was not easy over a hub connected 10BaseT network, especially to "certified network managers".

After slightly more than 2 years I returned to teaching computing and science-physics, this time at Bowral High School where I spent some time developing the Intranet resources, and now have turned to trying to prevent science education from becoming a "reality TV" production. I also spent some time teaching Adult Ed classes how to use e-mail (as it was becoming fashionable in local businesses) using a less than reliable link, and a LAN based Eudora e-mail server I installed on an disused iMac.

This part, in a sense the prelude, has taken 30 years. The most interesting part, in my opinion will happen in the next 5 years. I would say, we are entering a time when "productive skills and real knowledge" will become valuable commodities. The difficulty will be to determine who has the "productive skills and real knowledge" and what that would look like.

In the past 5 years I have been involved with managing the "Southern Highlands Science Spectacular" - our science fair, to provide a showcase for any local student who is willing to enter a science project and compete against others. Some of the students have gone on to win awards in regional contests. We expect that soon, some will also achieve merit at the state level. An interesting feature of this year's fair was an entry that scientifically tested the "covered leather shoe policy". Needless to say the project confirmed the policy. For two years we have had projects that test the learning skills of teenagers and adults - with person in front vs listening to iPod device. Both projects confirm that younger people learn better when listening to iPod devices, older with a person in front. While these may not be done to the very highest PhD standards, these results demonstrate that students, given the opportunity, are willing to rigourously test ideas that are often just hearsay. Last year we had a student draw 22 km of pen ink to demonstrate "which pen lasts the longest". We saw the evidence!

We may very well be on the cusp of moving from the analogue to digital age- or as I see it the age when someone else experience is more important than your own-especially if it is shared. This was brought home to me when a few years ago we took some Year 7 students to the zoo. They preferred to look at the animal exhibits through the display of a mobile phone rather than view with an unfiltered eye. A sad indictment indeed.

Students may be able to put on a 'show', but we must not be fooled by these emperors new clothes- the appearance may be different but they are still the same clothes. We should not blithely accept the doctrine "[just because] everyone else is doing it, [so should] we follow". If anything, we should stand to lead by real example- by knowing what to do and doing it. Being a teacher today is not an easy job- as if it ever was. It saddens me also to see recent graduates appear with a poor understanding of science, as if "science" is a minor part of their teaching skill base "to get a job".

The road ahead will have more choices, be more difficult to traverse, and more challenging than ever but more rewarding for those willing to put in the hard, but real, yakka. It's always been like that!

The Hardware-Software Nexus: Serial Port Protocol Modules in Computing Studies Education

Introduction

This article describes three components- an Radio Frequency IDentification(RFID) transponder module from Adilam, a Garmin Global Positioning System(GPS) receiver, and the PICAXE-08M micro-controller from Revolution Education. These Original Equipment Module(OEM) modules all support standard 4800 Baud, 8N1, RS-232c connectivity to Personal Computers(PCs) allowing students to easily use them as sophisticated sensor devices in their Visual Basic 6(VB6) projects.

The RFID module is powered by a 9V battery and is designed to signal by a short pules of light from a LED and a sound pulse from a piezo-electric device that a decoded RFID tag serial number has been successfully captured. At the same time the serial number is made available on its serial port.

The Garmin GPS receiver is a full receiver powered by a source from 8V to 20 V. It is intended to be used in vehicles. The Garmin GPS receiver is a full receiver sending its data stream of GPS sentences to a serial cable. It provides a continual data stream of “sentences” conforming to the NMEA common standard. This is available on the serial port.

The PICAXE-08M, part of the Revolution Education range of micro-controllers is normally associated with Technology Studies. However it is an excellent module for projects involving learning about the interface between high level programming languages, low level programming languages and connecting software and hardware.

These three devices represent a progression of complexity in the requirements to “make it work” and gives teachers intelligent sensors that can challenge students at different levels of understanding of the hardware-software nexus. The MSComm2 component must be installed in the VB6 Integrated Development Environment (IDE). This is the module providing the link between your application high level code and the underlying driver.

Connecting to the RFID Tag transponder Module

The module sends out 0-5 VDC RS-232C signals compatible with a standard RS-232C port on a PC. Using the PICAXE-08M The PICAXE-08M system in its very basic form comprises hardware and software.

The hardware is one of:

PICAXE-08M proto board, or AXE092 Schools Experimenter Board, or CHI040 8 Pin Project Board The PC-PICAXE interface cable (DB-9 to stereo 3.5 mm plug)

The software is supplied from their website for free and can be used after registration. It has recently been updated and is very easy to use. It includes extensive documentation that is very worthwhile reading before and during experimentation with the PIC-AXE system.

Although not necessary, the following test equipment will make experiments easier.

An oscilloscope (at least 10 MHz bandwidth) A multimeter (Volts for checking analogue/logic levels, Ohms for checking resistor values and continuity) A simple pulse generator - could be made from a PICAXE-08M module A simple logic probe - could be made from a PICAXE-08M module

Use of the Oscilloscope

Most science teachers are familiar with oscilloscopes and their use but this tool may not be familiar to teachers of Software Design and Development. The oscilloscope is able to display the time dependent “state” or voltage level of at least one pin of a logic/ analogue device. In addition oscilloscopes can make visible rapidly changing voltage levels. This can make visible logic level transitions. Unfortunately real-time analogue oscilloscopes are not capable of ‘storing” these traces. To store traces, you need a repeating series of events and photograph the image on the screen. An alternative is to use a digital storage oscilloscope(DSO). There are now becoming available relatively inexpensive “Front-end” modules that can make a PC into a digital storage oscilloscope. They are slightly cheaper than Analogue Oscilloscopes but are controlled via a PC. Many also are able to process digital data streams.

Use of the Multimeter

A multimeter is a combined instrument that can measure at least voltage or resistance. A voltmeter can be used to check logic levels (but not logic transitions). An ohmmeter can be used to determine continuity (short circuit or open circuit). Ohmmeters should only be used without power connected.

Use of a Pulse Generator

A pulse generator is useful for injecting repeating pulses into a circuit. They are normally powered from the circuit under test. This allows you to determine the response of the circuit using a logic probe.

Use of a Logic Probe

A logic probe can display the state of a pin and if the voltage level is within valid logic levels. They also are able to detect whether a pulse train is present on the pin being probed.

Motivation

These three devices represent a progression of complexity in the requirements to “make it work” and give teachers, intelligent sensors that can challenge students at different levels of understanding of the hardware-software nexus.

These three devices were chosen because of their compliance to the following criteria:

Serial Interface – without the difficulties of USB or Ethernet Send Only: RFID and GPS Receiver, or Send-Receive PICAXE-08M Data in the form of an ASCII String Decoding and sub-string selection required Physical robustness Safe power requirements (Batteries less than 12 V). How the students use these devices

I introduce these devices to them early on the course and require them to do two things, after a short discussion about the capabilities of each device:

Using the Internet research the device and how it works Obtain information about the RS232C protocol

When they have become familiar with the device of their choice, they are to write a 1 page project proposal on what they intend to do with the device and most importantly what the outcomes of the project will be. Often I have to edit this list to make the projects manageable in the given time frame- usually about 8 to 10 weeks.

There are some essential features of their project that must be addressed:

How to (in the case of the PICAXE) configure the micro-controller to produce a serial data stream (possibly from an attached sensor) How to connect the device to the PC How to configure the Serial Component within VB6 How to read the serial line, and put a complete line in a textbox How to modify the captured line to extract the essential information How to make use of the essential information

The simplest device to connect is the RFID module, because it sends a 16-byte stream of ASCII data to the serial port. In each case the VB6 computer application responds through an easily configured VB6 SerComms component.

Data Format for the RFID module output

The RFID module produces a data string with 16 bytes. The first and last bytes represent framing bytes to delimit the actual string of bytes and need to be stripped from the received string prior to use. A relatively simple project involves using the unique code from a tag as a key and matching it up with a data record. A student was able to do this in 2005, building a simple Pass In-Pass Out emulator for 4 students. The tag number, time in, time out, name and photograph were recorded. The project was also able to do the initial associating of a tag with a name and photograph. Data Format for the GPS module output

The GPS module is more complex to use than the RFID module that sends out “sentences” or CR-LF delimited sequences of ASCII code. These are encoded and require the VB6 application to decode and extract selected strings from the data stream. The next task is to convert these data items into a more useful form. For example, many GPS sentences, contain Latitude, Longitude and Altitude information.

At the simplest level, the student would only need to capture the Latitude(Lat), Longitude(Long) and Altitude(Alt) components of the data stream (from one of the GPS sentences) and display it in text boxes.

To make these data elements much more useful requires that a student learn how to convert Lat-Long data into screen coordinates (or scaled coordinates) on a screen. This is a major task and involves, at different levels of sophistication, use of linear transformations and trigonometric transformations. An HSC student in 2006 was able to produce a project where he could take the GPS receiver for a ride in his car around Bowral and it directly mapped readings (dots) on a GIF copy of the local street map on rendered on the screen of a PC, in similar fashion to “real” GPS receivers.

Data Format for the PICAXE module output

The PICAXE module is in some ways simpler than the GPS module. The sensor and “front end processor” are physically separated allowing the user to program how the signal from an attached sensor will be processed before being sent to the VB6 application.

This module involves attaching a sensor, obtaining a scaled value from the sensor within the PIC-08M processor, and then periodically (generally in 1 s to 5 s intervals) sending the read data to the serial port. The format of the serial data must be programmed, and this is where the complexity comes in. The student will need to understand many features of the system before a successful reception of data can be achieved and then the data can be used in the chosen application. The PICAXE is programmed entirely separately from VB6 and uses a simpler form of BASIC.

References

[1] For Garmin details refer to http://www.garmin.com/

[2] For PICAXE details refer to http://www.picaxe.com or Australian Distributor http://www.microzed.com.au/

[3] For Adilam details refer to http://www.adilamtech.com.au/faq.html