OK, so I've bought Mindstorms. What else would be useful?

This is an attempt to describe the possible add-on sets for the Lego(R) Mindstorms Robotics Invention System (abbreviated to RIS).

I've changed the format since the original version... on this page there is a brief description of controllers, actuators, sensors and generally-useful elements. Next to each item is a link ("sets") which links to a page which gives a non-exhaustive list of the retail/service/Dacta sets which contain that item.

The questions asked (and answered?!) are:

Controllers: what can I use to control my robots?
Actuators: what output devices are available?
- Motors
- Micro motor
- Pneumatics
- Light elements
- Fibre-optic system
- Sound elements
Sensors: what input devices are available?
What specialised Technic elements are useful, and where can I get them?
- Electrical connectors / extenders
- Differential
- Clutch
- Freewheeling 16 tooth gear
- Gear blocks
- Universal joint
- Flexible axle
- Large turntable
- Chain links
- Conveyor belt links

Controllers: what can I use to control my robots?

RCX #9709

The RCX has 3 inputs and 3 outputs, plus a bi-directional infra-red interface. It is a good general-purpose base for autonomous robots.(Sets)

Cybermaster

The Cybermaster has 3? inputs and 1 output, plus a bi-directional radio interface and two built-in motors. Tachometers on the built-in motors make this a good platform for mobile robots.

Scout

The Scout has 2(?) inputs and 2(?) outputs, plus a built-in light sensor. It has a fixed number of pre-programmed behaviours, and it doesn't look (yet) like you can program it like the RCX/Cybermaster, despite looking like the same hardware...

Micro-Scout

The Micro-Scout has a built-in light sensor and a built-in motor. It has a fixed number of pre-programmed behaviours, and it doesn't look (yet) like you can program it like the RCX/Cybermaster.

Control Centre #9752

The Control Center has 3 outputs, plus a constant 9V "test" output. It has 2 "memories" which can be used to "learn" a sequence of instructions.

Interface B #9751

The Interface B has 4 passive inputs (for touch and temperature sensors), 4 active inputs (for light and angle sensors) and 8 ouputs, plus a constant 9V "test" output. It interfaces to a PC (it may be a simple RS232 serial connection, in which case it would interface to any computer?)

Battery boxes #5114/#9831 and #5391

Don't knock the battery boxes - they can be very useful for testing your robots! There are currently two styles:

#5115/#9831 is the larger of the two. It has a two buttons, for forward and backward, and takes 6 AA batteries.

#5391 is the smaller box. It has a simple on-off switch, and takes a PP3(?) (9V cuboid) battery.

Actuators: what output devices are available?

Motors #5225 and #5114

There are currently two 9V motors:

#5114 is the older style of motor. It runs pretty fast, but the speed is affected by the applied load.

#5225 is the newer style of motor. It has an internal flywheel, which I suppose makes it run at a more constant speed than the old one.

Micro motor #5119

The micro motor is good for switches, steering and other low-speed, low-power tasks.

Pneumatics

Pneumatics are a powerful way of moving arms, grippers etc. You'll need an air tank/compressor, and a switching mechanism though, which will probably require two motors.

Light elements

There are a few light elements. Not really very exciting though.

Fibre-optic system

The fibre-optic system is a brick with a red LED inside; the LED can be rotated by an axle - normally a micro-motor is used for this. 8 bits of plastic (presumably fibre-optic cable) are attached to the brick, so that as the LED rotates, a cycling light effect is achieved. (Thanks to Mego1283@aol.com for the description)

Sound elements

The RCX can make noises, but there is also a separate sound element in the Dacta range, plus there were various sound elements in old Town/Space sets.

Sensors: what input devices are available?

Touch Sensors (various numbers!)

There are a variety of touch sensors available:

#9888 is the original Dacta sensor. It is yellow and has (I believe) the cable permanently attached.

#975? is the Mindstorms sensor. It is grey and doesn't have a permanently attached cable.

#???? (more than one number?) are the Cybermaster sensors. These are transparent, in various colours, each of which has different resistance, which allows the Cybermaster to detect which one has been pressed. I don't know if the RCX can detect this resistance though.