Carmelo Cinco
Indoor Basketball hoop with electronic scoring
St Patrick's College, Wellington
Year 13 Technology (Materials / Electronics / IT), one-year project
Teacher: Chris Smyth
Asked to design and build a piece of recreational equipment, Carmelo decided to make a scaled-down indoor basketball game with electronic scoring for his father.
Carmelo had recently moved to New Zealand from the Philippines as a senior student. As he was new to Technology, Carmelo had to learn new knowledge and skills in a number of areas to complete his project: how to shape, fabricate, and paint the structural components of his game; about electronic componentry and how to solder these into circuits; and about microcontrollers and simple programming, using the PICAXE microcontroller system.
Carmelo began by researching similar games, and planning his approach – identifying key factors, resources, potential sources of knowledge, and outlining a timeline for the project. He identified and involved a number of stakeholders, including two Technology teachers other than his own classroom teacher.
Carmelo measured a full-size basketball hoop and an indoor ball and scaled the dimensions of his game to suit. He bought a full-sized hoop, cut it down and re-welded it, and made a back plate and support braces and welded them into position. A backboard was made from MDF, cut, sanded, primed with acrylic paint, and sprayed with enamel. These jobs were done during lesson times, when workshop space was available.
As work on the hoop progressed, Carmelo studied electronics and practised his soldering. He used a PICAXE test circuit to learn and practise programming, writing draft or 'dummy' programs for the scoring system. As he worked, Carmelo documented and planned his technological practice in a visual diary, with notes, photographs, drawings and printouts of his programming.
Carmelo made a prototype of the circuit, using an 18 pin PICAXE chip as its heart. A particular challenge was finding the right kind of seven-segment LED display: the first display caused problems when it was integrated into the circuit board, but eventually a common anode display was found to be suitable and successfully tested.
Carmelo planned to use a microswitch with a paddle attached as the sensor to detect the passage of the ball through the hoop, but he decided, at the suggestion of his teacher, to use an LDR (light dependant resistor) instead, avoiding the need for mechanical contact. Hi-brite LEDs placed around the rim of the hoop help provide a consistent light level for the sensor to work in.
Carmelo looked at the work of Surveylab, a local design company with whom the school has worked extensively with in an enterprise link (see The St Patrick's College/SurveyLab Link), to see how professional technologists go about integrating the structures, electronics and programming required for a product when designing it.
After some manipulation, the elements of the game were assembled and made to work successfully. Carmelo intends to refine the game further. To improve the accuracy and reliability of the scoring system, he wants to establish a base-line for the detection of light level changes and change the program to enable it to compensate for changes in ambient light levels. He also plans to add a time delay to the system to do away with a bug that 'double scores' when the ball runs aroundthe rim before dropping. Carmelo is also working on constructing a pole 
and standfor the game, with a removable hoop and backboard for storage.
Teacher's comment:
Carmelo has accessed and synthesised a variety of knowledge and skills in producing a successful and well made outcome. It's fun to play and actually works really well.