For my final project I decided to go with a holiday theme. Every year I attend an event called SantaCon; it’s a gathering of people dressed in Santa and other Christmas-themed costumes. When I was thinking about Santa, two concepts stood out in my mind: sitting on his lap and his list (naughty or nice). With the arsenal of techniques we learned this semester, I decided a pressure sensor in the lap that triggers a judgement (naughty or nice) displayed on pockets would be appropriate.
I used a pre-made Santa costume that I was comfortable with modifying. First I sized up the jacket to determine the proper placement for the naughty/nice pockets.
I printed out the words and traced them using a permanent marker on sheer fabric. I also used a thin layer of filler material to diffuse the LED backlights.
Once I ran the LEDs through the coat I hot glued the pockets on top.
I first laid out the circuit: red/green LEDs to indicate naughty or nice and a pressure sensor (foil on either side of the anti static foam).
For the complete system, I wrapped the core Arduino and wires with plastic to contain everything and then attached a string to hang the entire assembly around my neck. The assembled pressure sensors used two layers of the foam with foil on both sides, sides taped up, and a lead running to the microprocessor; I used Velcro straps to secure the sensors to my legs. I first tried to attach the sensors to the inside of the pants; however, it became difficult to take them on and off, so I changed things so that I could attach the electronics to my body before putting on the jacket and pants.
Because I was putting on the jacket after the electronics, I decided to use snaps to attach the LEDs.
One question that came up was how you determine if somebody is naughty or nice. I played with different configurations for a capacitive sensor, but it was ineffective when it was up against my body. What I ended up going with was using a random number generator, seeded by the reading from the sensor.