Reflection

Hall effect sensor and IR rangefinder worked flawlessly for this purpose. However, the FSR reading varied widely depending on where on the floor it's placed, and dog's movement/position in relation to the FSR position. Three things could be done to remedy this, one being diagonally placing two FSR and getting an average read between the two as the variable. The other is to use a flex sensor, taking advantage of the plastic tray flexing as the dog sits on it. Finally, a larger FSR could be used and placed on top of the tray (and under the cushion). The last option might be the most accurate, but it runs the risk of dog digging it out and destroying it.