P-Buddies: A Children’s Construction Kit for Building Interactive Play Spaces
a project with Carla Gomez Monroy, Chris Lyon, and Thomas J. McLeish

The P-Buddy Kit is composed of a set of simple robust sensors and output devices that children can add to their existing play space and toys. With it children can build simple playroom surprises, games for themselves to play, and interactive fantasy spaces. Even with the most basic elements—a single sensor and output device—a child can create engaging surprises for friends. For instance, a proximity sensor and a speaker on a chair might be used to make a digital whoopee cushion. A child can use sensors that observe her environment. These sensors might used to create many kinds of appealing toys, such a sister spy sensor or a pet monitoring system. More complex and sophisticated interactions can be built by combining multiple inputs and outputs. Children to build treasure hunts for their friends or enhance fantasy worlds and play. They can build puzzles based on a particular sequence of behavior. These games might be similar to sequence repetition games like Simon or Boppit in which children repeat the sequences the machines generate, except that children could use their entire bodies and entire rooms and design the interaction themselves.

A Scenario
 An working prototype and example scenario was built using the Media Lab’s Grassroots Invention Group’s Tower System as a central processor and the Lifelong Kindergarten Group’s Cricket-bus devices as sensors and outputs. The sensors were light, sound, and proximity. The outputs were speakers, tricolor LED’s and servos.

Figure 1: Elements used in the prototype scenario.

In this example scenario, a room was transformed into a fantasy treasure hunt in a jungle. When the door was first opened, the children would hear jungle sounds. After a few moments, a speaker behind a stuffed bird said, “Find my egg.” The children would search for the egg and when they picked it up, their action would be sensed by a light sensor. The bird then said, “Warm my egg.” The children would put the egg in the bird’s nest, which was sensed by another light sensor. Then a chair said, “Allie is hungry.” The children decided that Allie must be the cutout of an alligator on the trashcan. They would throw the egg in the trash, a distance sensor would sense the movement, and the LED eyes of the alligator would blink. As the alligator would say, “yummy,” a servo would make the alligator’s mouth ‘chew’ the egg. Finally, creatures all over the room would howl, bark and cackle.

The Interface
 After developing the prototype, it became evident that the key to making this highly generic system support successful interactive and programmable play-spaces is to design a simple, yet robust programming interface. In the final interface, each sensor or output device is a separate object and both the sequence of actions and the behavior of individual objects are programmed by physically manipulating the object. Since children program with the toys (as opposed to at a computer), fantasy play and imaginative thought can occur while programming.

Each sensor or output device is embedded into a small creature called a Programabuddy or P-Buddy. A P-Buddy is plush fabric creature approximately 5 inches high. All P-Buddies, (except two, which will be discussed later) have a dial and button as controls and a small LED embedded between the antennae as a display. The dial is a foot at the bottom of the creature.

Children can program the sequence of the interaction between the inputs and outputs, along with the sensitivity of the sensors and the content of the display of the outputs. Both sensors and outputs can be used multiple times by simply activating them again later in a sequence. The sequence of sensors and outputs is programmed by the order the individual P-balls are activated. When a child wishes to run the sequence, he presses the single button a special P-ball called the P-Mama. This device is a master switch for starting and stopping the interaction. The Programama also contains electronics that coordinate all of the sensors and output activity.

Figure 2: 3 P-balls (from left to right): LightBall, Programama and SoundBall.

All sensors are programmed in the same way. First, the button is pressed to indicate that this sensor is the next in the sequence. Then, the dial in the foot is turned until the appropriate threshold is reached. Reaching threshold is indicated by the LED on the device. Once a sensor is programmed, a child can then activate the next P-Buddy in the sequence by pressing the dial on that second creature.

The following sensors are available:

  • Light for sensing changes in environment or a switch that is covered or uncovered.
  • Optical distance senses movement and proximity.
  • Sound sensor.

The following devices are available for output:

  • Voice playback for up to 16 minutes and speaker.
  • Tricolor LEDs with controls for color and fade timing.
  • Motors to make things move.

The output devices work in a similar fashion to the sensors. First, the child presses the button to activate the output next in the sequence. Then, he turns the dial or, in the case of the speaker, presses a second button, to program the content of the output. The content of each output device is programmed slightly differently. To program the LED, the child would turn Programaball upside down to reveal circular rainbow running around the foot. As the child turns the foot-dial towards the different colors, the colors change. Depending on how fast the child turns the foot-dial, the color will change at a fast or slow speed accordingly. To program the speaker, the child would press the second button to record the sound and then press it again to end the recording. To program the servo, the child would turn the foot-dial at the speed and direction (clockwise or counterclockwise) he wishes the servo to move.

Newton's World: exploring motion, mass, and momentum through play
a project with Oren Zuckerman and Kan

Newton's world was a project inspired by:

  • Seymour Papert 's Microworld concept and focus upon hands-on activity & debugging
  • Friedrich Froebel design philosophy: Tools for exploring world, knowledge, & beauty
  • Newton’s Three Laws of Motion

Newton's World was a mockup of a sense-table application for kids aged 6-18. The idea was that kids could interact with physical shapes on the table and watch digital clones move through the simulation world. A variety of activities could be formed such as modelling constellations, trying to make arrows hit targets, trying to make cars avoid hitting, and create pleasing patterns through repetitive forms and through exploration, deepen understanding of Newton's laws of motion, mass, momentum, gravitational forces and inter-dependencies and how patterns are formed from shapes.

The Interaction

  • Adding an object to the system – placing any physical object on the sense-table will automatically generate the digital clone of the object, displayed at the same position of the physical object.
  • Setting an object’s mass – by default, every object added to the system has a calculated ‘mass’, derived from the object’s 2D top-level area.
  • Setting an object in motion – pushing an object in a specific direction will set the digital clone in motion.
  • Stopping an object’s motion – ‘catching’ the moving digital clone using the original physical object will stop any object from moving.
  • Removing an object from the system – placing the original object on top of the clone and lifting it up will remove the digital clone from the system. (only with objects which are not set in motion).
  • Multiple Object Interaction: by default, every object in the system has a gravitational force, calculated from the object’s mass. For example, by adding a second object to a running simulation of one object moving in a straight line, the gravitational pull of the second object will cause the first object to circle around it.

Components

  • Object – Can be of any shape emits 32bit id for sense table to identify
  • Sensetable – 2 watcom tablets
  • Video Recorder / Projector – Computer vision for tracking and identifying shapes and also for projecting simulations and renderings onto the Sensetable
  • Object and Shape Identifier and Tracker - PC for identifying specific 2-D shapes and sizes from Sensetable video feed which will be used to later determine mass and other object properties and for tracking of movement of objects and gestures of human users.
  • Physics Engine – Models the world for each specific simulation whether it is building a solar system, racing cars, or simulating rain. Determines object mass, size, etc. The output is sent to the display renderer.
  • Display Renderer - to render into shapes and lines for display, output sent to video projector

 

Last modified 14 January, 2003