Week 4 - Continuation of Sketch One Assignment

This week, we continued to work on our Sketch One Assignment. We had most of our assignment done from last week, so the only thing we had left to do was complete the implementation of the backpack with our pressure sensors and testing to see if it was correct. We also had to tweak the numbers to fit the weight being distributed in the backpack.

When working on the programming, Arduino part of our project, we programmed the Arduino so the four pressure sensors would sense the weight being distributed. If a person was wearing the backpack in the wrong way (i.e. wearing it too low or one strap on the shoulder), the red LED light would light up.

There are a total of 5 LED lights on the backpack. We programmed it so that the green would light up first, then yellow and then red. So as a person puts more weight into the backpack, the lights will light up accordingly to the numbers that we put in for the programming. We based our programming on the average person of 140 lbs. We used this number from the researched we did and how much the average person can carry (around 22lbs).


For the implementation part of our project, we used tape to put over the conductive thread so it wouldn't touch the other threads conducting. We sowed the thread into the two straps of the backpack and slipped it inside. The Arduino board ideally will be put inside the backpack. We hooked up the Arduino board to each of the LED threads so it would light up accordingly. We sowed each thread carefully, away from each other to the four sensors to the Arduino board. We also used conductive tape where needed. We used black tape to keep some of the thread in place as well.


In our presentation for Sketch One, we included a description of our concept, how it is used and its experience. In the next slide, we talked about concept research behind our project and also techical research (anti-static foam, inspiration from instructables site and existing/related projects). Some of the research we talked about was Brandon Macias' study on shoulder/backpack pain with children, the Carlie Backpack and the DC backpack. After the presentation was made, we finalized everything and prepared the presentation for each of us.

The presentation can be seen here:
http://www.sfu.ca/~ach3/320presentation.pdf