LEGOs bring robotics to the classroom

Medford, MA--Name things that engineers love and LEGOs would be at the top of the list. Now the Center for Educational Outreach at Tufts University in a program with LEGO Dacta (Billund, Denmark), makers of the colorful building toy, are bringing a robotics educational program to K-12 classrooms starting the middle of September.

LEGO Dacta's ROBOLAB(TM) program kits use LEGO-based components and National Instruments (Austin, TX) LabVIEW(TM) software to teach engineering and science skills in a student-friendly manner via the long-time favorite toy of children (and parents).

Another brick in the wall. The system uses components that can be integrated with LEGO's familiar interlocking bricks and parts to produce various machines and mechanical systems. Projects possible with the kit start at the lower grade levels with devices such as a bumper car that can respond to obstacles. Advanced motion control includes systems like a haunted-house ride with a pop-up skeleton and ghost. Students learn programming, robotics, and automation as they build their projects.

The key ROBOLAB component is the programmable RCX brick. According to Mike Giuggio, LEGO Dacta project manager, this 3.5 X 2 X 3-inch LEGO-made unit contains three sensor input ports, three motor- or lamp-powering output ports, and a liquid-crystal display. Four switches on the RCX are for turning power on or off; designating the output port to be displayed; selecting one of five stored programs; and starting and stopping a program. The display indicates such functions as data communication status, elapsed operating time, run status, and available memory when data logging. An ac adapter or a 6-AA-battery pack supplies the brick's power.

An Hitachi (Brisbane, CA) H8/3294 microcontroller is the heart of the RCX. It has 16 Kbytes of internal ROM and 512 bytes of internal static RAM (SRAM). In the brick, external to the microcontroller, there is an additional 32 Kbytes of SRAM. Some of the internal code is downloaded from an external computer into a portion of RAM. ROBOLAB is compatible with Macs or PC platforms running Windows 95, 98, or NT. Students can compile programs on the computer for downloading into the RCX by a infrared (IR) wireless link. The code entered into RAM can be changed for any future RCX features. The remainder of internal code is used in downloading applications, programs and datalogging.

But you don't need a computer to run ROBOLAB. While the RCX can store five programs, for operations without a computer there are five built-in programs to run. These must be downloaded if the RCX has been previously used with a computer. The brick also has a built-in speaker, three timers with resolution of 0.1 second, and the IR transmitter. Two or more RCX units can communicate with each other via IR.

Chris Rogers, associate professor of mechanical engineering at Tufts, had the guiding vision behind ROBOLAB. After many years of research, he says the developers picked LabVIEW for ROBOLAB because of its icon-based interface. "We chose it for our system because it is easy to teach students fundamental programming skills with the graphical programming language." While it is a standard tool for engineers, Rogers notes, "Its simple graphical interface allows kids as young as kindergartners to use it with ease."

Sensors. Input sensors developed by LEGO Dacta include a light-reflectance sensor. Light from the unit's red LED reflects off surfaces and into the detector. The intensity sensed could, for instance, determine the color of passing LEGO bricks for various processing commands. The angle position sensor is an LED-based optical rotary encoder having a disk of 16 segments. A membrane on/off switch in a LEGO brick is a touch sensor.

ROBOLAB comes with a robotics guide software manual, a teacher's activity pack with worksheets and concept guide, and instructions for four models. The 293 LEGO elements with the set include two motors, one light sensor, two touch sensors, wire connectors, the RCX brick, and a lamp. Cost is $300 and the set is available to schools and individuals through the LEGO Dacta website:www.lego.com/dacta. The initial versions in English for the North American market will be joined in January by those for local markets worldwide. LEGO MINDSTORMS(reg), a more-limited version for children 11 and up, is in stores and uses a Logo computer architecture developed by LEGO and MIT.

Robert Rasmussen, LEGO Dacta director of R&D, says the company plans to build on ROBOLAB with additional education products in autonomous robotics. "Science exploration will be combined with data collection and logging, such as with robotic rovers."