LEGO Education

Meet the Sensors: Sound Sensor

The sound sensor included in the new MINDSTORMS Education NXT base set is a sophisticated sensor that allows you to use a new stimulus for directing a robot’s actions. The sensor measures dB and dBA, meaning it can tell if a command is given in a normal “inside” voice and one given in a loud “outside” voice. Or you could program the robot to perform a given task one way if a single person gives a command, and to perform differently if lots of people give it the same command simultaneously. The sound sensor also recognizes sound pattern recognition. One clap, for instance, could be programmed to command a certain behavior, but two claps could be programmed to do a behavior that is much different. In addition to sound pattern recognition, the sensor also features tone recognition. A high pitch would command a different action than a low pitch. Think of the possibilities – you could write a program that performs in tandem with a musical performance, and applause could then trigger an encore performance!

Get Excited About NXT: Driving Straight Lines With Ease

Tufts University’s Center for Engineering Educational Outreach has worked with the LEGO RCX for a long time. We’ve run hundreds of programs for K-12 students and teachers. One of the first projects we do with kids and teachers is to build a car that will drive in a straight line. With wheels attached directly to the motors, the task can actually be quite challenging. In our aging and eclectic collection of LEGO components the motors are often mismatched, causing the car to veer in one direction or the other. Students and teachers often compensate for this in their design by making one axle and wheel extend further or even by adjusting motor speeds in extreme cases. But, it’s not an exact science and for young students it’s very hard to explain to them why their car doesn’t go straight. Many advanced users have come up with all kind of innovative solutions for this issue, including creating their own rotation sensors. However, we are really excited about the NXT's new servo motors. With built in rotation sensors, it will be easy to create a car with the new motors that performs consistently. Users will be able to configure their motors to go forward for a specific amount of rotations or speed. This will make straight line driving a piece of cake. We think this will be great for new students and teachers to easily create robust and reliable creations the first time they start building. It’ll be a great confidence boost for first time users to be able to create an incredible, repeatable robot the first time out.

Education Extras: Rechargeable Battery

Lots of people are wondering about the differences between the MINDSTORMS NXT that will be available from various retailers and the MINDSTORMS Education NXT that LEGO Education will be selling. There are quite a few differences, actually. The MINDSTORMS Education NXT offers lots of extra features that will provide increased value in any learning environment.

One of these Education Extras is the rechargeable battery. The 1400 mAh lithium battery more than replaces AA batteries that run down quickly and cost so much to replace – it has a minimum capacity of 670% of 6 AA batteries (although you can still use AA batteries in a pinch).  It doesn’t take long to recharge, either. Only 4 hours are required to charge the battery from zero to full. And, since it’s a lithium battery, you can partially charge it or leave it charging overnight without having to worry about any negative effects. There’s also an A/C plug in the battery to allow the NXT brick to run from a direct power supply when needed.

The rechargeable battery will only come with the MINDSTORMS Education NXT, and will be available individually from LEGO Education.

Meet the Sensors: Light Sensor

The new light sensor is an improvement on the existing light sensor that is included in the existing MINDSTORMS for Schools set. It is a much more sensitive sensor, allowing more precision in light measurement along a scale of 0 (no light) to 100 (very bright). It is also possible to turn off the infrared light source that is located below the sensor, so that the sensor only measures the ambient light from its surroundings. Just like the touch sensor, the look and feel of the sensor has been updated to support the TECHNIC-based building system and to match the NXT brick.

Meet the Sensors: Touch Sensor

The touch sensor that will be included in the new MINDSTORMS Education NXT base set is very similar to the touch sensor that is included in the existing MINDSTORMS for Schools set. The look and feel of the sensor has been updated to support the TECHNIC-based building system and to match the NXT brick. The new touch sensor does have a hole for an axel in the push-button, giving users more options for incorporating the touch sensor into their designs. Both the new and the existing touch sensors are very basic sensors - they can only be on (allowing the electrical flow to move unimpeded) or off (interrupting the electrical flow). You can see how the electrical flow is allowed or interrupted in the simple diagram on the right. A robot can initiate an action or reaction when it senses a change in voltage due to the electrical flow starting or stopping.

Meet the Sensors: Rotation Sensor

Unlike the existing MINDSTORMS for Schools, the Mindstorms NXT for Education does not have a stand-alone rotation sensor.  In the NXT system, a rotation sensor is built-in each of the three servo motors, and the LCD display on the NXT brick shows the number of rotations as they are counted.  These built-in sensors should provide an easier-to-use, more accurate count of rotation than the existing rotation sensor used with the RCX brick.  Some projects may still need a rotation sensor that is not connected to the motors, however.  In these cases, the converter cable that is provided with the NXT for Education base set is just the solution, as it will allow existing sensors to be connected to the NXT brick.