The project page provides links to their Arduino code, ... salvaged the weight sensors from some cheap bathroom scales and rigged them up with some plywood discs to serve as the base for each keg.

Arduino is able to interpret signals from a variety of sensors. By placing a unit equipped with an ADXL345, an accelerometer for detecting motion, or a Piezo sensor on a door, it can notify you ...

This project investigates the use of wood as a scale, so that people in a wood-frame building can be detected in real time (e.g., for intruder detection and energy conservation) and creating "smart" ...