Spring Quarter Project Proposal

ECE 191

Wireless Bathroom Scale

Paul Blair, Ph.D.

pblair@ucsd.edu

Introduction

Researchers at the PACE Research Group within the UCSD School of Medicine are exploring how physical activity, diet and other health-related behaviors can be optimized through the innovative use of science and technology.  Within the past year, PACE researchers have begun to incorporate wireless technologies, cell phones and Bluetooth into their projects to provide real-time assessment and interventions. Several of their projects study obesity. Subjects who are successful at losing and maintaining body weight, weigh themselves daily and are aware of their loss/gain trends.  However, not everyone is diligent at self-reporting his or her weight. Furthermore, since weight (as reported by the scale) can vary by 5+ pounds (depending on time of day, clothing weight, amount of fluid in body, etc), accurate recording of the date and time is essential.

Project Requirements

Objective: Build a bathroom scale that can be used in future PACE clinical trials.  The scale must be self-contained and battery-powered (with a long battery life), suitable for use in the average bathroom.  The scale will automatically timestamp and record the user’s weight.  Data is stored in the scale (for up to 44 days) until the user downloads the data into a Bluetooth-enabled cellphone for transmission to the PACE webserver.

Hardware components: An inexpensive (<$50) digital bathroom scale will be modified and integrated with a Bluetooth transmitter and a microcontroller.  Students will need to find an appropriate bathroom scale and determine the best way to interface to its display. All other necessary components have been procured, but there are several implementation challenges.

Bluetooth interface to cellphone:  An existing Blu2i module will be interfaced to the microcontroller to transmit collected data to a phone for uploading to the webserver. 

Microcontroller software development: Students will be required to develop microcontroller software that timestamps and stores the user’s weight and uploads to the cellphone.  Phone software development is not a required component for the current quarter.