Delivery – Year 12
The 2006 Year 12 class, taught by Bill, undertook the following programme:
Term 1: Learn to program microcontrollers, write brief for 2.1 Game project
Term 2: Complete game project and begin data and information project
Term 3: Continue on data and information project
Term 4: Documentation of evidence for the externals and send portfolio to Wellington. Individual consultations.
Bill started writing the resource material for this course in 2003 and had refined it each year. The material was available on the website, and is published in a 164 page workbook entitled An Introduction to Microcontroller Electronics and Software Design.
"I originally started using the website to distribute information, but then, using Moodle , I tinkered with interactive exercises targeting a particular skill that students need to master."
Again the workbook plots out a comprehensive and detailed course, and includes templates and tutorials interspersed with exercises, research tasks and assignments, in BASCOM and AVR, number conversion, microcontroller, game and speed control programming, light meters, strings, ASCII and various maths tasks.
During the first term students only do programming exercises. "I want Year 12 students to develop a very solid set of understandings in programming and to learn how to problem-solve. In circuitry, its too easy for students to say 'I have this micro-processor – I can just hang off some switches and some input devices, and make some LEDs and motors as output devices' without understanding what exactly is going on. It's about how to take a problem, pull it apart, and explore it to come up with some sort of algorithm to solve it
"We started by looking at a food processor. It's relatively straight forward: its got an on/off switch, a two speed motor with a switch, and a safety switch. So I get students to tease it apart and look how the designers solved its little sub-problems piece by piece: the motor will only go if this and this happens, and the motor will go at half speed if A, B and C happen, and it won't go if A is left out.
"Then we looked at a toaster because its much more complex. It has two outputs – a heater output and a solenoid output to lift the toast. For inputs there's a variable control for the toast , buttons giving different options and a timer. So we explore how all of these different things interact.
Once students understand what's happening, they write software for that system and play around with it. "Technological practice is all about planning, so understanding a problem and teasing it apart is all part of a planning process. Students have to be able to solve the problem in their mind before they can look at it on a computer. It's called 'problem decomposition' – breaking down a big problem into smaller ones that can be solved more easily. I get students to apply the same process when they come to solve their own problem with a game."
For the game project Bill limits the parameters to five switches, a potentiometer as the input, and some LEDs and a liquid crystal display for the output, and they have to work within those confines. "All I want is a conceptual design, and that is very simple – we don't need to build a huge snowboard game. This project lasts a term and is internally assessed using AS2.1. It also fulfils a lot of their skill learning in electronics and particularly programming."
During the game project Bill spends quite a bit of time talking about context. Gaming has rich and broad social issues – there are people in the US, Bill explains, suing game-makers over how it affects users' behaviour.
To explore context, Bill gets students to conceptualise a game. "I say let's find an issue and someone will say, 'I wait for the bus every day'. So I'll say 'why don't we develop a game people can play while they're waiting for the bus every day? Maybe its attached to the pole, and someone will play it and when they hop on the bus the next person can take over where they left off'. Because with a conceptual design we don't have to solve the problem just think up something and tease out the logic of how it would work, we can get riskier with the games and broaden the whole context."
Students then move on to the data and information project, where they are asked to find data in one environment and transmit that data to another.
"We might look at an anemometer. A wind surfer will want to know what sail to use in particular wind conditions. We can use a microprocessor to measure the wind speed to calculate which of five sails to use and present that to the user. We make the problem a bit more complex by using a radio system to pick up the data at one location and transmit it to another."
"By the end of Year 12, I want my students to be able to write a reasonable sized piece of software – 50 to 100 lines of code – and to be able to look at a micro-controller and do the basics with it. Their projects don't look as impressive as the Year 11s – they look like little plastic boxes with things stuck in them. But it's what's inside them that's just amazing."
"Then in Year 13 they'll be ready to learn how to add on hi-tech components to it, how to add on a real time clock to keep track of time in real world, how to drive a motor, and the complexities involved in driving motors."
