November 24, 2007
Reading for November 27th, are now posted. Enjoy!

October 2, 2007
To upload your thoughtless acts, create a new assignment page like any other lab. You'll see "Thoughtless Acts" listed as one of the assignment options.

May 24, 2008
This site has been archived and is no longer editable. Stay tuned for the next version, coming in the fall!

Sensor Mechanism

Project Members: 

Here the idea was to create a mechanical device for the FSR to mediate between its small sensor and real-world objects that exert force on other things.  I decided on a platform that things could be set on and that focuses force on its center (padded with paper towels) so that, in concept, the LED lights could be activated when weight is lifted from this platform.  I keep imagining a light that comes on in a dim room when some item is lifted up, something that is natural and would naturally necessitate turning on a light before using.  The idea could be expanded, I would hope to the point that a pressure sensor could be placed in a chair, so that when a butt is planted the lights in a room are off (leaving only the computer screen at the desk on), but that when the sitter gets up, the room's lights come on so that he/she can find the door without tripping all over the junk on the floor.  This is an invention that would aid me greatly in my many spontaneous dashes across dark and uncertain space (the bathroom break you can't put off any longer, etc.).

Wasabi Pea Can plastic lid.
"Defend Free Speech:" pin.
Paper Towels
LED fade circuit/breadboard from previous assignments.

For the FSR project, I used the 1LED fade code we used before with the POT's.  I just added the two other LED's and then changed the part of the code which assigned the value to the LED light so that the lights would be most dim when a lot of pressure is applied to the FSR, and so that as pressure is let up the lights grow brighter.  Here is what I changed:

analogWrite(led1Pin, 255-val/4);

Visual Evidence:

Pressure Platform with focusing spike: A Plastic lid with a small pin fastened to the underside
Pressure Platform with focusing spike: A Plastic lid with a small pin fastened to the underside

Underside of Lid
Underside of Lid

Disaster Waiting: The Idea... sort of
Disaster Waiting: The Idea... sort of


your bathroom use-case

your bathroom use-case motivates this lab very well :) Please remember to post your code for others to share in the glory!

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