Week 19 Log

Week beginning 13/02/2012

This week primarily involved research into and the development of paper prototypes, xBee to Arduino radio configuration and implementation as well as some conceptual development.  There was also some hardware and user testing with the paper prototypes and exploration of ‘what’ the project could be.

‘Building Wireless Sensor Networks’ was used with the xBee radios and the Arduino development environment. It was an extensive process, but fully documented for future reference. An early problem experienced was the xBee adapter hack: at first this was not working, but it turned out that this was simply because the breakout boards had not been soldered on. The breakout board function is to space out the pins on the xBee which are too close together to fit onto a breadboard. The first soldering attempt was unsuccessful as the wrong method had been used which resulted in the need to replace the breakout board. The correct method was adopted through a youtube tutorial and these were soldered correctly. However, due to the poor quality of the iron the tip degraded almost completely so this had to be replaced. Following this, the xBee radios were  tested and configured according to instructions. Due to a crossed wire in the router module, this didn’t work but once this was corrected the system worked correctly. Note: this is mentioned as being the primary source of errors in an electronics project. Following the successful completion of the ‘doorbell’ project, a wireless version of the early paper chair prototype was created. There were a few coding errors, but this was overcome by looking through the arduino discussion forums.

Paper prototyping is a much researched and much used methodology within the field of HCI (Human Computer Interaction), and it has proved valuable within the early stages of the project. ‘Paper prototyping’ by Carolyn Synder was referred to in the development in the first user tests of the project. Paper prototyping is mainly used for screen based interfaces, but the idea of ‘task modelling’ was extracted and applied to a non-screen based interface.  To make a paper prototype, according to the book, the designer selects tasks to be tested, and models how the user would execute these. For this project, tasks were selected and modelled. For example the user was given a paper key to ‘unlock’ the device, and where there was text input this was simulated by writing on the prototype in the correct place. Two user tests were conducted with the paper prototype and it proved invaluable in both the explanation of the concepts and introduction of the abstract paper prototype but in generating ideas.

Some of the problems that were introduced by prototyping both in Google SketchUp and in paper were the issues of security and of proximity sensing. One option was to use a magnetism sensitive ‘hall effect sensor’ and a magnet as a physical key and lock. This was mocked up on a single board. The problem was that although it worked, it was unreliable and this may be due to the size and shape of the magnet and its field. Proximity sensing with light sensor is unreliable due to the effect of environmental factors i.e. day and night.

This week has also involved the discussion of methodologies that would result in the definition of a specific purpose or purposes for an outcome. There was also the appreciation for location flexibility: ‘does it have to be static’? There was the explanation of scenarios and device pairings. The next stage involves exploration of its placement within the world and within user’s environments. The concept being brought to users and discussed is crucial. Bringing more interactive prototypes to users with working elements could be extremely beneficial and participant observation of different contexts will be carried out.