For our physical computing media controller project Inessah, Amik and I decided to create a confetti machine where the user can control the height of the confetti by raising and lowering their hand. We first tried using a DC computer fan with a ultra sonic sensor which worked perfectly for controlling the speed of the fan based on the distance of your hand but it soon became clear that a 12 volt computer fan wasn’t at all powerful enough to blow a large amount of confetti more than about a foot.
Once we realized we needed a fan upgrade we went down to a industrial fan shop on Canal street and picked up a hefty 120 volt AC fan. After purchasing said fan we found out that in order to control it with the Arduino we needed to use a relay because you cant have AC power running directly into the micro processor. A relay basically is just a on and off switch controlled by the Arduino. Because we are only able to turn it on and off we lost the ability to control the speed. But our professor Tom Igoe had a great suggestion of pulsing the fan at different intervals to replicate a change in speed.
Once we had control of the fan we started working on designing and constructing the container. Working with wind was much more difficult than we originally anticipated the container we designed was wider at the bottom and became narrower at the top of the base to try to focus as much of the wind into the confetti container. We also ran into the issue of static electricity, most of the confetti ended up sticking to the sides of the container. To remedy this we wiped the interior down with anti-static computer screen spray, this seemed to help things significantly. Another later addition to the box was to make the bottom opening where the fan was blowing into smaller and more focused. All of these last minute tweaks improved things but I am sure we can improve upon this and make it even better down the road.