Matt Cheung (, Kangyuan Niu (, Min Hun Lee (, and Christabel Wai (


Coasters that can weigh the contents of the cups they are under and wirelessly communicate their fullness to interested parties.


In restaurants, it is sometimes hard for waiters to pay attention to all guests and refill their drinks in time. With Drink Sense coasters, the amount of liquid left in a guest's cup can be determined and sent to a central notification station in real time, allowing waiters to prioritize and efficiently perform their drink-refilling duties.

Competitive Analysis

Somebody tried this project last year, but it wasn't completed because their coasters weren't waterproof. Ours will be.

Microsoft and NVidia are making giant touch-sensitive tables that cost tens of thousands of dollars. Ours will be much, much cheapter.


  1. Weight detection
  2. Wireless communication
  3. USB Dongle and accompanying PC software for coaster management
  4. Flashy LED indicators
  5. Inductive charging with indicating LED

Technical Specification

Pictures of Components

Cost totals around $150.

Protocols Used

Just XBee.