This is a home-brewed weight scale project. The main purpose is to build myself and my wife a smart scale that can upload our data automatically to website for fun, and without worry about the scale battery.
This project is NOT well documented, and only being here for giving you a rough idea what can be done.
If you want detailed instructions, you may find some better story here: http://forums.electricimp.com/discussion/290/wifi-weight-scale