Building Mighty Mouse

The mouse contains three motors and five sensors - two that sense light and three that sense touch.
 

Two motors power the wheels that let the mouse move around the mouse pad - and the table.
  (left motor)

How the mouse works:

The sensors and motors are connected by a small computer called a handy-board. Written code is downloaded onto the handy-board and instructs the motors to turn on and off in response to changes in the sensors.

For example, when you pet the mouse, you end up pressing two touch sensors on the mouse's back. If both sensors are touched at the same time, the motor connected to the tail turns on for a few seconds, which causes the tail to "wag."

Shining a flashlight on the mouse causes light to fall on the two light sensors on the front of the mouse. When the right light sensor receives more light than the left sensor, the mouse turns right (right motor on, left motor off). The reverse happens on the left side and the mouse ends up following the light.

To get the mouse back into the house, you press the touch sensor between the ears. This action tells the mouse to turn around (left motor on forward, right motor on backwards) until it sees the light shining out of its house. The mouse then follows the light to the house the same way it followed the flashlight earlier. Once the mouse gets inside the house, the flashlight turns off, and it is now darker in the house that it was on the table. When the light sensors on the mouse receive very little light, the mouse is

instructed to turn around again for about one minute. To us, the mouse appears to have gone into its house, and then turned around to "peek out."

Our mouse went through several transformations along the way:
Here is one of the early versions

From the front	the back	the side	and the top