Sensing Part 2: Force Sensitive Resistors and Photocells
OBJECTIVE
This lab introduces us to two new sensors - the Photocell and the Force Sensor. We also learn how to use Processing to implement cross platform programs.
MATERIALS REQUIRED
PhotoCell, FSR sensor, Arduino Uno, LEDs, Connecting Wires, 10K Resistor
MECHANICAL: Using the FSR
Description:
Use Force Sensitive Resistor (FSR) and Photocell to control a sketch on Processing and find a creative material to apply to the FSR.
Materials: Plastic Clip, Felt, Force Sensor, Resistors, Capacitor
Outcome:
I created "game controller" like hand-piece out of the clip, felt, and force sensor to manipulate an image of a turtle generated using Processing. Pressing the left side of the clip causes the turtle to move left, pressing the right side of the clip causes the turtle to move right, and pressing neither side leaves the turtle where he is at.
http://www.youtube.com/watch?v=aOk7kb7EOGw
Arduino code:
Description
Use FSR to control rotation of image
I tried to rotate a picture of person by the FSR sensor. I calculated the rotation angle to rotate 360 degree when the val is 255, so the rotation angle was PI*2*val/255 in radian. I was hoping to show movement, but it got to just add layers of the image on top.
Description:
Used photocell and force sensitive resistor to control brightness of an LED. Then used them to with Processing to control shapes on screen. Also created a mechanical system to distribute force on FSR using a pen.
Materials used:
The FSR is placed so that it senses the level of water in a glass. I used cotton in between so that the force gets more directed towards the center of the sensor (the most sensitive part). The computer displays a physical simulation of falling drops of water under gravity force alone. The program updates object's positions based on their previous location, mass (proportional to the cube of their scale on the display) and gravity force, which is directly read from the Arduino's serial output.
