I'm working on my graduate thesis project and need to find a cheap way to measure the weight of the contents of a plastic bin that is part of my larger project. I need it to measure up to 25 lbs. with a circuit built directly underneath the bin. I looked at a post by killerdark (http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1221027834) and tried the exact same thing to no avail.
I'm wondering if anyone might have some suggestions for building my own weight scale or strain gauge of sorts to interface with Arduino (an/or and op amp if needed) without using expensive load cells. I'm not so much concerned about accuracy as I am about cost. Do you think FSR's would to the trick? I've even thought about placing the bin over stretch sensors and reading weight that way...as you can tell, I'm definitely not a pro with anything dealing with electronics, so any expert advice or direction would be greatly appreciated.