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The PICAXE in Education . . . In the January issue we briefly mentioned the success of the PICAXE Fair and the display by students from East Hills Girls Technology High School. With the 2005 school year commencing even as this issue of SILICON CHIP goes on sale, we thought it timely to have a more detailed look at the achievements of the girls and where it is hoped this will lead in the future. W hile many schools and colleges will have finished organising their 2005 subject and course offerings and indeed various curriculum options, a lot don’t really set them in concrete until the second or third week of the new year – ie, right about now! We’re hoping that this feature might prompt or shape some of the choices schools and colleges make – as in, “we could do that too!” And even if it is too late for this semester or even this year, maybe we might be able to “sow the seeds” for 2006. OK, enough preamble: let’s go back to where this all started: the PICAXE siliconchip.com.au fair – and where we went from there. In the lead-up to the PICAXE fair, PICAXE enthusiasts and groups were invited to bring their projects and/or designs along for all to see and evaluate – including the “father” of the PICAXE, Clive Seager, Technical Director of Revolution Electronics (UK). Clive made the trip to Australia specifically for the PICAXE fair and to further preach the PICAXE gospel. Incidentally, it was acknowledged at the fair that Australia has probably the highest per-capita interests and usages by Ross Tester of PICAXEs in the world. That’s due in no small part to the infectious enthusiasm of SILICON CHIP’s regular contributor, Stan Swan and his incredibly popular PICAXE column in the magazine. If Clive Seager is the father of the PICAXE, Stan Swan must be regarded as Professor PICAXE in this part of the world. You might expect that Stan has a financial interest in promoting the PICAXE – the truth is, Stan is another educator: a lecturer at Massey University in Wellington, NZ and his interest stems (at least in part) from getting his students as keen about this technology February 2005  79 With teachers Steve Sharp (left) and Anthony Rotondo, the girls from East Hills Girls Technology High School are holding their pride and joy, along with the extensive documentation they prepared for it. Pictured are Samantha, Alisha, Fiona, Eleanor, Kim-Anh, Jessica and (back row) Victoria and Sarah. as he is. (As well as in the pages of SILICON CHIP you’ll find Stan on his website, www.picaxe.orcon.net.nz). Back, though, to the PICAXE fair: IT students from East Hills Girls Technology High School entered their PICAXE project and were awarded first prize for their efforts. Ped-X As soon as Leo Simpson and I walked into the PICAXE fair, Stan dragged us across the room to the East Hills Girls Technology High School display and their “PED-X – the new generation of technology”. “You’ve gotta see thus,” he said. (Remember, he’s a Kiwi). As its name suggests, PED-X has something to do with pedestrian crossings. Something to do with? PED-X is a fully automated pedestrian crossing control system driven, surprise surprise, by a PICAXE (in this case, an 18X). The girls, all from classes which sit either the School Certificate or the 80  Silicon Chip Higher School Certificate later this year, had made a model of a pedestrian crossing, complete with LED traffic and pedestrian lights. First, it automatically sensed the presence of a pedestrian, checked to see if it was one of those “push button and run” nuisances we’ve all experienced (the ones who delight in stopping traffic because they can!). If the person was still at the crossing the traffic control phase was started with the usual amber then red light, then green pedestrian “walk” light. At the same time it sensed whether it was day or night and if the latter, also activated road-mounted indicator lights ahead of and at the crossing to give drivers more visual notice that a crossing was being used. As Tim Shaw would say “but wait, there’s more . . .”. Their crossing also had sensors embedded in the crossing itself to ensure that older pedestrians had in fact completed the crossing, before switching the traffic control lights back to green. For good measure, they also included an initialisation or POST (power on, self test) routine to make sure the crossing lights always came up they way they should after a power failure. In the case of the model, it is of course powered by battery – but there is nothing to stop this type of control system being implemented in full-size, fair-dinkum pedestrian crossings. If you used LED arrays for the traffic control lights, all you’d need would be a few driver transistors and it would work exactly the same as the model. In fact, one of the design features was that a full-sized system could have battery backup and so keep working during a power failure. So it was, a few days after the fair (and just before the school holidays) we arranged a visit to East Hills Girls Technology High School. The challenge The girls embarked on the project as a challenge to broaden their learning experience, in keeping with the siliconchip.com.au A close-up of the model PED-X researched and created by the girls in year nine. The overall design and programming was done by year 11 IT students. It is completely automatic and changes its operation depending on speed of pedestrians and time of day. About East Hills Girls Technology High School philosophy of the school. Their challenge: not to build a better mousetrap but design and build a better, safer pedestrian crossing. Under the guidance of Steve Sharp, Head Teacher IT, Anthony Rotondo, IT teacher and Lesley Kaye, the girls took on the challenge and came up with a project which has many elements which could influence design in the “real thing.” With limited-to-zero experience in programming, electronics and modelmaking, students were divided into two teams: the (then) Year 9 Computing Studies class were to research the subject in depth and create the model, while the (then) Year 11 Software Design and Development set the parameters for their better pedestrian crossing and then developed the software to run it. Steve Sharp assisted them with the electronics. Their research found that about one in six road deaths were pedestrians and that of the 290 fatalities in 2001, 93 were people aged 65 or over – or one eighth of the population contributed to one third of pedestrian fatalities. The girls concluded that with an ageing population, by the year 2041 if other factors remain unchanged, statistically one third of the fatalities will be of pedestrians 85 years of age and over. Clearly, that was an unacceptable prospect. embedded lights on the median strip and on the crossing itself as a warning to drivers. (3) Sensors on the road which check to see if cars are driving by, to keep the pedestrian lights on red. (4) Sound augmentation for the vision-impaired. (5) Crossing time to be customised to pedestrians. (6) Sensors to detect the amount of light (ie night/dusk/bad weather etc) The Ped-X was designed to give particularly older people but also visually impaired pedestrians a much safer way of crossing the road. The team’s observations suggested that many of these people do not have enough time to safely cross the road. The Ped-X overcomes this by sensing the progress of people on the crossing itself. Whether you are an Olympic athlete or a person on a walking frame, it will not return the traffic control lights to green before crossing is completed. In the model, this was achieved by the use of magnets tripping reed switches embedded in the pavement. The girls were first to acknowledge that this was not a “real world” situation but also suggested that there were a number of ways to sense the location of people on the crossing – passive infrared, microwave and other methods were suggested. The project “How much difficulty was there writing the code,” I asked. The software creators, Eleanor, Fiona, Jessica and Kim, replied that they found it quite difficult to start off but once they had the basic knowledge (no pun intended!) it got easier and easier. In the end, they told me, they were really enjoying writing and refining With the research behind them, the girls brain-stormed the requirements for a better crossing. They came up with key design factors: (1) No buttons to press – the crossing would be completely automatic. (2) Not only the “normal” pedestrian and traffic control lights but also siliconchip.com.au Coding Principals, leading teachers and administrators looking to expand their school’s subject choices and the depth of their curricula could well look at the example of East Hills Girls Technology High School. While it is a “technology” school, many of the Key Learning Areas and programs set up at the school should be adaptable into mainstream or comprehensive high schools and colleges, with significant advantages for both teachers and students. East Hills Girls Technology High School is located in the south-western suburbs of Sydney and is believed to be the sole girls-only technology high school in the country (while located across the road from East Hills Boys Technology High School, the two schools are independent of one another). At the end of 2004, there were more than 950 girls enrolled at the school with over half travelling from outside its “normal” catchment area. Fortunately the school is within a few hundred metres of Panania railway station. Computing Studies is a compulsory subject for all students in years nine and ten and the Specialist Information Technology faculty has five full-time staff. As well as offering a broad range of subject choices in Information Technology in the senior school, it also teaches the district Gifted and Talented class in IT – year eleven students are able to complete Certificate II in Information Technology and the HSC in one year. The school has five computer classrooms, a video production unit, darkroom and specialist rooms for technological studies, sciences, creative arts and drama. Industrial Technology – Electronics is offered as a course for years nine and ten students, teaching basic electronics, robotics, computer systems and components. February 2005  81 INITIALIZATION Sets lights and reads analog sensor. Go to Sees if sensor 0 or 7 is on. If it is, go to sensor check, if off then loop. LOOP If 0 or 7 on SENSOR CHECK Waits. Checks sensors 0 and 7 again (to see if pedestrians have run away). Checks amount of light. ANALOG SENSOR If less than original lighting then low cross. If higher If lower LOW CROSS CROSS The future Changes traffic light to red, crossing to green. Low cross has median strip lights. Go to If crossing is active CROSS CHECK If no-one is on crossing 2 and 6 then delay 2 seconds. If sensors 2 and 6 ON then loop to cross check again. If no-one is on crossing DELAY 2 Waits 10 seconds and then goes to crossing Go to CROSSING Red on. Amber off. Green off. Crossing green off. Flashes green, flashes red. Go to INITIALIZATION This flowchart shows the operation of PED-X. 82  Silicon Chip the software, getting it to do exactly what they wanted it to do. That’s one of the beauties of the PICAXE, of course: coding is very easy to learn, even for a beginner. It also doesn’t require any dedicated programmer – as readers who have been following Stan Swan’s PICAXE project know, all you need are two resistors and you code direct from your PC. It could hardly be simpler! As for the PED-X project, Steve Sharp said that the PICAXE is a superb system for students to gain knowledge in both programming and mecatronics. With very simple, low cost components, the girls have proven it possible to build solutions to quite complex problems. “Since the model is totally controlled by software, the program can be easily erased and the PICAXE made available to the next group of enterprising software engineers,” he said. “Imagine what type of solution they might come up with!” The knowledge and skills gained by the students at East Hills Girls Technology High School in the preparation of PED-X has been excellent. Simply by actually building models such as this allows students to bridge the gap between programs they create on the computer to how those programs actually work in real life. In addition, the hands-on experience has allowed them to develop excellent problem-solving skills – skills which will be invaluable for their School Certificate and Higher School Certificate later in the year and into their future careers. Many of the girls involved in the project plan to make their careers in some aspect of information technology, whether through further study at University/TAFE or by directly entering the workforce. In addition to the skills learned in the PICAXE project, their studies have introduced them to a wide variety of topics in the IT area – everything from basic word processing and spreadsheets right through to animation and graphic design. As Stan Swan rightly points out overleaf, “It’s my view that Picaxes are truly an educator’s dream.” Now all we have to do is convince the hundreds of other schools and colleges teaching technology to take up that dream! siliconchip.com.au Stan’s Corner . . . You can perhaps thank Google for the Australasian Picaxe takeoff! It was only mid 2002, while helping a NZ high school battle with budgets and boredom in an electronics class project, that I’d reflected “there’s just got to be a better way – especially for today’s PlayStation/text message/web page generation!” Although microcontrollers had become well established in the electronics industry, their costs or steep learning curves meant both staff and students dismissed them as unsuitable for the average student (or stressed teacher!), especially given limited class instruction time and tight resources. When a lengthy Google session unearthed the (then) little-known Revolution Education’s Picaxe offerings, I’d initially thought their $5 prices were a misprint, since at even $50 each they’d have been good value! But $5 they were and they’ve since “just worked” as absurdly cheap, versatile and powerful (yet easy to use) engines, amply justifying my 2003 “New Millenium 555” reflections and enthusiasm. It’s my view that Picaxes are truly an educator’s dream, especially given the reduced component needs a project now requires. Suitable capacitors out of stock for a 555 R-C timer? Wrong value thermistors purchased? Budget cleaned out for a year-end technology project? Want the siliconchip.com.au kids to take something home to show off or work on? With a Picaxe, only trivial components may be needed, with desired circuit alterations made via the program editor, perhaps even reusing earlier hardware! It’s a triumph of key strokes over components. Aside from the bargain prices, educationally where the Picaxe family really shine is perhaps as a liberator from normal hard-wired circuits that can only really be tested when finally assembled and powered up. The resulting puff of smoke and associated agony of defeat that crushes many new electronics students is almost alien to Picaxe designs, as ideas can often be incrementally developed and verified as one goes – rather like doing a crossword puzzle. This rapid reinforcement, combined with extremely supportive internet resources, serves to stimulate new learners and provide almost a 3-D aerial view of an electronic design. It’s akin to a General flying high over a battle field for a campaign overview. Such self-directed learning can encourage rank beginners to explore possibilities. But it especially empowers lateral thinkers who may be continually pushing “what if” design boundaries anyway, hopefully as a stimulus for more powerful controllers and even an electronics career. Under such a learning scheme students may need less initial formal theoretical instruction and instead largely “learn by doing”, correcting mistakes and expanding ideas as they go, much as word processing now empowers writers. Hence seductive LED patterns, CRC data massaging or even memoryhungry musical tunes might call for maths algorithms that’d normally be considered very tedious if taught as stand-alone theory. Given the high level commands employed, it’s even tempting to speculate Picaxes may appeal to foreign students keen to enhance their English language skills. Late teen Asian students introduced to them here in NZ show an enthusiasm that perhaps relates to the simultaneous English and Electronics benefits arising! SC February 2005  83