Force Sensitive Resistor, Thin Film Pressure Sensor, ZD10-100 Force Flex Sensor, Force Sensing Resistor, with Fast Response, 0-500g

This is really not terribly stable, especially with reasonably fast changes in force (weight, in my case).What I did was use a moving average function to smooth-out the incoming data. It takes a little overhead, but I use internal interrupts in the controller to help keep the CPU load down.A simple moving average made the readings more reasonable. If you have this triggering something, you need to add a fair bit of hysteresis to the circuit so that you don't get bouncing, because this thing on its own will bounce. Price fits the performance.

The sensor measures to be about 3/8" wide and 3-5/16" long, with an overall length of 4-3/16". The leads are 1/4" long and about 22 AWG pins.The sensor measures out of range resistance with no force applied and ranges down to about 400 ohms pushing as hard as I can against the desk. The resistance changes very quickly when applying force to the sensor, as well as when releasing.The resistance is also slightly inconsistent when applying the same weight to the sensor in different locations on different occasions. Specifically, a 1x1 tungsten cube was applied at the extreme ends and center of the sensor with about 150ohms in variance (max-min readings) over 3 separate data runs with an average of approximately 715 ohms.Folding the sensor onto itself (in a manner that did not crease the sensor) yielded a resistance varying from 800ohms to 1.5kohms over 3 trials.Overall, this is a good sensor for most hobbyists. This probably would not make a good sensor for use in a dynamic system, as the range of resistance only appears close to linear toward the upper end of it's range and is far from linear toward the low end of its range. This sensor would be good for basic binary operations (on/off) or possibly 3 setting control (off/low/high) given this information.