Friday, February 20, 2009

Mindstorms Educational Robot

LEGO Mindstorms is a line of Lego sets combining programmable bricks with electric motors, sensors, Lego bricks, and Lego Technic pieces (such as gears, axles, and beams).

Mindstorms originated from the programmable sensor blocks used in the line of educational toys. The first retail version of Lego Mindstorms was released in 1998 and marketed commercially as the Robotics Invention System (RIS). The current version was released in 2006 as Lego Mindstorms NXT.

The hardware and software roots of the Mindstorms Robotics Invention System kit go back to the programmable brick created at the MIT Media lab. This brick was programmed in Brick Logo. The first visual programming environment, called LEGOsheets,[1] for this brick was created by the University of Colorado in 1994 and was based on AgentSheets.

The original Mindstorms Robotics Invention System kit contained two motors, two touch sensors, and one light sensor. The NXT version has three servo motors and four sensors for touch, light, sound, and distance. Lego Mindstorms may be used to build a model of an embedded system with computer-controlled electromechanical parts. Many kinds of real-life embedded systems, from elevator controllers to industrial robots, may be modelled using Mindstorms.

Mindstorms kits are also sold and used as an educational tool, originally through a partnership between Lego and the MIT Media Laboratory.[2][3] The educational version of the products is called Lego Mindstorms for Schools, and comes with the ROBOLAB GUI-based programming software, developed at Tufts University[4] using the National Instruments LabVIEW as an engine. The only difference between the educational series, known as the "Challenge Set", and the consumer series, known as the "Inventor Set", is another included light sensor and several more gearing options.

Sensors are connected to the NXT brick using a 6-position modular connector that features both analog and digital interfaces. The analog interface is backward-compatible (using an adapter) with the older Robotics Invention System. The digital interface is capable of both I2C and RS-485 communication.

NXT Sensor Interface Pinout
Pin Name Function Color Pin Numbering
1 ANA Analog interface, +9V Supply Pin 1 - ANA
2 GND Ground Pin 2 - GND
3 GND Ground Pin 3 - GND
4 IPOWERA +4.3V Supply Pin 4 - IPOWERA
5 DIGIAI0 I2C Clock (SCL), RS-485 A Pin 5 - DIGIAI0
6 DIGIAI1 I2C Data (SDA), RS-485 B Pin 6 - DIGIAI1