05 October 2018
4 min read
Based on constructionism from Seymour Papert, MIT Media lab and the Lego group collaborated to push Lego to the digital world. Lego was losing market space against the virtual worlds from the video-game industry and educational robotics looked like a good fit for the Lego parts, letting kids explore the real world through robots built with their own hands. Gears, motors and many parts were already available from Lego Technic kits, but sensors, a programmable brick and a programming environment were missing to achieve a robotics kit for education. The kits were named as Lego Mindstorms due to the book Mindstorms: Children, Computers, and Powerful Ideas by Seymour Papert.
| RCX | NXT | EV3 | |
|---|---|---|---|
| Release | 1998 | 2006 | 2013 |
| Display | segmented | 100x64 pixels | 178x128 pixels |
| Processor | H8/300 @16MHz | ARM7 @48MHz | ARM9 @300MHz |
| RAM | 32 KB | 64 KB | 64 MB |
| ROM | 16 KB | 256 KB Flash | 16 MB Flash + microSDHC |
| USB | No | No | Yes |
| Bluetooth | No | Yes | Yes |
A new model, 51515, became available in 2020. This page is updated as new sets are released and more information is found online.
The RCX is the first fully programmable Lego brick came to the market in 1998, after a long relationship between MIT Media Lab and the Lego company and appeared in many sets. The RCX could control 3 motors or lights, and 3 sensors simultaneously, which included: a touch sensor, a light/color sensor, a temperature sensor, and an angle sensor. The RCX itself could emmit sounds and use its built-in infrared sensor to be programmed and communicate with other robots. The version 1.0 included a power adapter that was later removed, which forced robots to be powered by 6 AA batteries. The RCX starts with 3 built-in programs that are stored for testing purposes. User defined programs are lost if the RCX is left without power. Kits included an infrared serial tower to let a computer communicate with the robot, later on replaced by USB towers. Such towers can still be configured to work with Linux, more specifically the Raspberry Pi. A firmware must be sent to the RCX before programming starts, many options are available with different levels of compatibility. In order to not be limited to Lego provided programming options, mostly based on drag-and-drop code blocks, users can program their robots with NQC. Due to the lack of inputs and outputs some users extended their robots capabilities with modified hardware, for example with a multiplexer. You can find out more about the RCX in the following places:
The RCX is a great introductory robotics kit, but due to cost and programming requirements (which require a computer not at hand for many kids) the RCX is simply too much. A simpler solution came in the Scout, MicroScout and Spybotics sets. The idea is simple: have less electronic parts (merge controller, sensors, motors, battery into a single element) and a few behaviors preprogrammed to explore. New behaviors can be programmed using a Barcode language (VLL) to introduce commands to the robot. The Scout (9735) is very similar to RCX, with less input and output ports (2 for each instead of 3) while using the same wires, motors and sensors from RCX, with a light sensor attached to the controller. The MicroScout (9748 and 9754) and Spybotics (3806, 3807, 3808 and 3809) took the other path: a single electronic element for everything. The Code Pilot (8479) from 1997 is probably the first example of Barcode/VLL usage in Lego sets.
Such sets are easier to setup and play with the multiple behaviors programmed, but the Lego group noticed that some users would like go beyond. After the user explored the default programs within the system, it is time to explore the P program.
The next generation of Mindstorms came in two versions, the first in July 2006 and the second one in August 2009. Previous sensors and motors are no longer compatible with RCX as new connections have been introduced.
The evolution of Mindstorms created the third release of Lego robots in September 2013. Sensors and motors are retro-compatible with NXT ones due to no modifications to the cables.
Several other pieces and sets are related to adding electronics parts to Lego. They are different from the Mindstorms, as they usually require a user remote controlling the machine. However they can be interfaced with smarter parts to achieve robot status.
Electric motors have been introduced much earlier than sensors and microcontrollers, enough to add movement to trains and small machines. Motors alone are limited to one direction and speed until the user interacts with a switch. With mechanical parts and gears it is possible to exploit the continuous movement of the motors to achieve more complex movements. A notable example is the Great Ball Contraption, a modular system which moves balls to the next module in the most creative way possible.
In 2007 Lego introduced a new connector for motors and sensors, resembling the one from the RCX era with studs. Such system is seen as a simpler way to add motorized/remote control features to model that are otherwise manually operated. Some recent sets have a dedicated space to add Power Functions. A list of Power Function sets is available here.
Features smartphone app programming and is available through the sets:
TODO