LEGO Mindstorms NXT is a programmable robotics kit released by LEGO in late July 2006. It replaced the first-generation LEGO Mindstorms kit, which was called the Robotics Invention System. The base kit ships in two versions: the Retail Version (set #8527) and the Education Base Set (set #9797). It comes with the NXT-G programming software, or optionally LabVIEW for LEGO MINDSTORMS. A variety of unofficial languages exist, such as NXC, NBC, leJOS NXJ, and RobotC. A new version of the set, the new Lego Mindstorms NXT 2.0, was released on August 1, 2009, featuring a colour sensor and other upgraded capabilities.
NXT Intelligent Brick
The main component in the kit is a brick-shaped computer called the NXT Intelligent Brick AKA(Ciara). It can take input from up to four sensors and control up to three motors, via RJ12 cables, very much similar to but incompatible with RJ11 phone cords. The brick has a 100×60 pixel monochrome LCD display and four buttons that can be used to navigate a user interface using hierarchical menus. It has a 32-bit ARM7 Atmel AT91SAM7S256 microcontroller with 256KB of FLASH memory and 64KB of RAM, plus an 8-bit Atmel AVR ATmega48 microcontroller, and bluetooth support. It also has a speaker and can play sound files at sampling rates up to 8 kHz. Power is supplied by 6 AA (1.5 V each) batteries in the consumer version of the kit and by a Li-Ion rechargeable battery and charger in the educational version.
The Intelligent Brick remains unchanged with NXT 2.0. A black version of the brick was made to celebrate the 10th anniversary of the Mindstorms System with no change to the internals.
Firmware and developer kits
LEGO has released the firmware for the NXT Intelligent Brick as open source, along with schematics for all hardware components.
Several developer kits are available that contain documentation for the NXT:
- Software Developer Kit (SDK), includes information on host USB drivers, executable file format, and bytecode reference
- Hardware Developer Kit (HDK), includes documentation and schematics for the NXT brick and sensors
- Bluetooth Developer Kit (BDK), documents the protocols used for Bluetooth communications