Lego Mindstorms NXT and Leopard Bluetooth

The LEGO Mindstorms NXT robotics kit has been out for two years now. And, even though you see a lot of books about it (such as these books in the O'Reilly catalog - LEGO Mindstorms books), I've noticed two oddities. First, you rarely read about it in gadget oriented sites and blogs. And, second, if you do find it mentioned somewhere, it is rarely Mac specific. I'm hoping to help remedy the second item by discussing the Mac and Mindstorms NXT here now and then as time permits.

LEGO Mindstorms NXT is a second generation robotics kit that was launched in the summer of 2006. It was a follow-up the original LEGO Mindstorms Robotics Invention System (RIS) that came out in 1998. The two systems are so different that they do even vaguely resemble each other. I was kind of taken aback when I realized that the familiar old-school bricks had been replaced by the newer generation Technics type parts. After a bit of reflection, I had to admit that it made sense from a construction and movement point of view. Also gone was the somewhat unlikeable (IMHO) infrared data transmission from computer to intelligent brick. It was replaced by a very realiable USB with wireless Bluetooth as an alternative (or so I thought). The first generation NXT 1.0 software didn't support Bluetooth on the then new Intel-based Macs. Plugging and unplugging a USB cable seemed a big annoyance during a development session. So, I lost interest in my relatively expensive (US $249.99 list price) toy inexpensive robotics kit. However, the NXT 1.1 update (a $20 upgrade, I might add) became available in the summer of 2007. And, this update supported Bluetooth on Intel-based Macs. This revived my interest (I bought the update) but didn't have time to play with it back then.

The kit includes a bunch of Technic parts, an NXT Intelligent Brick (the brain of the system that costs $134.99 to replace, btw), three servo motors, and four sensors (touch, sound, light, ultrasonic distance measurement). There are five additional sensors available from LEGO (compass, color, accelerometer, gyroscopic, infrared communications link). Mindsensors.com provides a third party set of NXT add-on devices including a vision subsystem, sensor multiplexor, and real-time clock.

This is the first screen you see after starting up the NXT software on the Mac. The programming for the NXT brick is pure graphical flowchart type design. There's no code involved. While this lets kids (and adults for that matter) get off to an easy start, I think that LEGO should have included a Logo Turtle Geometry programming language interface to the kit. There are real programming languages for the brick. But, I'll postpone that topic for another time.

I installed the on a first generation Macbook. I installed these updates over a USB cable connection since the updates patched Bluetooth issues. Detecting and pairing the NXT Intelligent Brick to the Macbook was smooth and simple even before applying the firmware update to the brick, though.

This screen cap shows the Bluetooth communications status between the Macbook and the NXT brick. You can see that I had not yet applied the brick firmware update when this screen cap was made, battery level, brick storage information, and the fact that the two devices were connected.

The first thing I did was to send a simple application from the Macbook to the NXT brick to test the Bluetooth connection. This app doesn't need any sensor or actuator to be attached. Running the app on the brick has it say You're Good through the brick's built-in speaker.

That's it for this first effort to bring the Mac-Mindstorms NXT connection to the masses. More later as time permits. Remember: You're never too old for LEGO. In fact, there's an acronym/term for this: AFOL (Adult Fan Of LEGO).