Ying-zong Huang

EE281 Project,Stanford University, Fall 2002

Wireless Freeform Input Device




Simply put, this project, in its current form, is a tilt-based wireless mouse. The hardware has two portions: a handheld part and a base-station. The handheld part senses the tilt angle that it is held at via a 2D accelerometer, processes the tilt data, and sends it across a radio link. It also has two buttons corresponding to two mouse buttons. The base station, which is connected to a serial port, receives the radio data and sends it on to the computer. At the output, the system emulates a standard serial port mouse. It is a inertial-mode mouse, which means the tilt angle corresponds to a velocity and not to an absolute position. In this sense, this project resembles certain gaming devices, especially tilt-based gamepads, more than a traditional mouse, but it is fit for either purpose.

(Left to right, transmitter front, transmitter back, receiver front, receiver back)


I chose this project because it seems like a wireless mouse that needs no surface is something nice to have. It's interesting to be a couple of feet away from the computer, sit back, and browse the web. (Technically, you can be 300 feet away, but then you really can't see your mouse cursor. I suppose this activity is more feasible on a projector.) There are more useful applications, such as using this as a writeable laser pointer for Powerpoint.

Acknowledgment also goes to Bob Dougherty of the Psychology Department for this project idea.