MIT Technology Review

March/April 2012

Rolling, Rolling, Rolling ...

A toy ball moves under the command of a smart-phone application.

Much of the fun of the Sphero toy comes from its mysterious nature: it has no buttons, no battery cover, no socket for a charger. Shake it and the globe glows with colored light. Put it on the floor, call up its control application on a smart phone, and the Sphero springs to life, trundling around at the direction of an on-screen virtual joystick. The $130 Sphero is made by Orbotix, a company that Ian Bernstein and Adam Wilson originally founded to sell Bluetooth-based control technology to manufacturers of other devices. But Bernstein and Wilson were advised that the best advertisement for their technology would be a product; a consequent late-night brainstorming session spawned the Sphero.

A. Charging Dock
The ball rests in a dock that uses an induction system to transfer electricity to the Sphero's two lithium-polymer batteries. A complete charge takes about three hours and provides 75 minutes of continuous driving time.

B. Wheels
Two independently controlled rubber-rimmed wheels inside the Sphero steer and drive the ball at up to 1.2 meters per second.

C.  Top Slip Bearing
Because the internal mechanism can move freely inside the plastic case, this bearing braces the mechanism when necessary, in order to keep the Sphero's wheels in firm contact with the shell.

D. Printed Circuit Board
A processor combines data from a three-axis accelerometer and a gyroscope to produce the precise measurements of the Sphero's roll, pitch, and yaw. These measurements are required to respond correctly to commands radioed by a smart phone over a Bluetooth connection.

E. Bluetooth Radio and Antenna
This system, with a maximum range of over 50 meters in optimum conditions, is used to communicate with mobile devices. Developers can download a software development kit from Orbotix and write their own iOS or Android control applications for the Sphero.

F.  Multicolor LED
The light from a single LED package with red, green, and blue elements is diffused by the translucent casing to make the Sphero glow. Different colors signal information such as whether the device is charging or when the motor speed is being temporarily boosted. The user can select the colors by way of the smart-phone application.

Watch Sphero in action below.