Weight/pressure sensor guidance


I need some guidance on how should I approach this issue.

My main goal is to be able to measure the change in weight. For example: I put a full glass of water on the sensor and then I drink half of it, and then Arduino can tell me that approximately half of glass is empty (or half full for optimistic persons :slight_smile: ).

The most simple approach that I can think of is adding a simple weight sensor along with an amplifier so that Arduino can read it, but the downside would be size (height to be exact). Almost all of the sensors are approximately 2 cm in height, but it still needs some mounting so the height could increase.

Other approach, which I am not sure of, is using a FCR (example: Here). Would it be able to measure the percentage in weight drop accurately enough? Maybe someone could suggest an even better approach? Thank you!

Sparkfun sells a 0.2mm thick load sensor.

You'll need to make a base plate and top plate to focus the load on the sensing area.