Wednesday, January 21, 2009

Use more than one motor per port on the NXT!!

While playing around with a few #8528 Converter cables for the NXT, I realised that the cables might have another application other than allowing you to use RCX sensors and motors in your creations. After finding a few NXT Servo motors, I began my experiment:

First of all, I connected two servo motors together using two of the converter cables, with the brick-like plugs connected in the middle. By spinning one motor, the other also turned - so creating a simple generator. This is fairly simple physics, and was only the beginning.

I tried out the different orientations that each plug could have with one another, and discovered a useful piece of information - by connecting the RCX style plugs in opposite directions you reverse the ploarity of the motors - so one motor will spin clockwise, and one anti-clockwise. See the Table below:

Note: The direction of the cable is the opposite of where the cable conects to the RCX plug

This is still fairly simple, but can be quite interesting for beginners to the NXT.

Next (pun intended ;-)), I connected a third converter cable to the other two, so that I could plug the two motors into the NXT but use only one port. Then I wrote a simple program using the standard on-brick programmer on the NXT brick to power motor port A. This was a success, and both motors were powered.

The downside to this?  The built-in rotation sensor in the NXT servo motors will no longer work while using a combination of these converter cables - so all measurements must be in seconds (e.g. power motor port A for 10 seconds). Also, I wouldn't recommend using more than 4 motors on one port,  but I am not too sure as to what would happen if you did, as I don't want to risk my NXT brick just yet!

But there you have it - it is possible, and fairly easy, to have more than one motor per port on the NXT, without having to make homebrew cables. And as you get 3 of these cables in the NXT Education kit, it is also quite practical.

Tuesday, January 13, 2009

LEGO TECHNIC Design School

While looking through some old files, I found a link to the LEGO TECHNIC Design School, which can no longer be accessed via the LEGO TECHNIC website. However, the Design School is still up and running, with 3 lessons on TECHNIC basics, which are quite useful to read when constructing a MINDSTORMS robot.

The 3 lessons available are:

TECHNIC 101 - The basics - quite literally. Talks about the LEGO measurement of 1M, etc, and goes over each of the TECHNIC pieces available and what they are used for

Gears 101 - More interesting and definately worth a read if you are still fairly new to gears and how they work. Can also teach an old dog new tricks ;-)

Stability with LEGO TECHNIC - Shows you how to make stable structures for your creations

Each lesson also has a quick quiz at the end for users who are logged in.

The TECHNIC Design School can be found here, and it can be found by searching for it using Google.

Saturday, January 10, 2009

New Temperature Sensor!

Now available via LEGO Education is the NXT Temperature Sensor!

Quoted from the LEGO Education Website:

"This digital temperature sensor can be calibrated to measure both Celsius and Fahrenheit using the NXT Intelligent Brick and the LEGO® MINDSTORMS® Education Software v.2.0"

The sensor currently costs $40 USD, and I would recommend getting both the sensor and NXT-G 2.0 at the same time, because as well as saving on postage and packaing costs, you also require NXT-G 2.0 to use the sensor (according to above quote)

Tuesday, January 6, 2009

NXT-G 2.0 Edu out now!!

NXT-G 2.0 Edu is now available through LEGO Education!! Here is what the description says:

"This powerful, easy-to-use software for programming and data logging is icon based and incorporates Robot Educator, a step-by-step guide with 46 tutorials, from beginner to advanced levels. Data-logging functionalities, including graph viewer, make it easy to collect and analyze data from sensors. The software incorporates a comprehensive digital user manual. The software is Mac OS X, Windows XP, and Vista compatible."

LEGO Education

Can't wait to see the new datalogging feature? Try this MyBlock from Guy Ziv at NXTasy!!!

--> Datalogging block at NXTasy
--> Link to NXT-G 2.0 page on LEGO Ed

Mindstorms Pedal

When I saw Dave Parker's NXT Electric Guitar, I immediately thought about creating a Pedal to go with it. The pedal, when pressed, could perform a range of actions, including changing the sounds used (single note to chord), add a drum beat, or perform another useful task.

Here is my first attempt at creating a pedal. It uses one touch sensor, so it could be seen as a simple on/off switch - in which case it could be used for beginning a drum beat.

But there are many other applications for this pedal. You could create a car simulator and use it as a brake or acceleration pedal, just one example of what can be done.

Experiment and see what you can come up with!! Dave Parker has published his NXT Electric Guitar here at, as well as many other interesting projects - all of which can be built with one NXT kit!! Have a look if you haven't already.