'Crickets' - Realization

TWK

3 Realization

3.1 Suggestions and Wishes

In order to get in touch with the kids and mentors at the CCE, participation in the daily life at the Clubhouse has been an essential aspect of the project from the very beginning. According to their curriculum at school and other activities, most kids come to the CCE on certain days of the week. In addition to these regular visitors, there is also a significant number of kids who come on a rather irregular basis, e.g. once in a month.

As the CCE offers a great variety of activities, the kids’ foremost reasons to come to the Clubhouse are very different, as well.

Browsing the Internet and chatting is what most of the kids tell spontaneously when asked about their motivation. However, this is not what they spend most of their time on! According to a survey conducted earlier this year (see [5]], digital image editing and word processing as well as designing a personal homepage for the Internet are the most popular and time-consuming activities.

Most of this can be summarized as recreational activities. But many kids also use the CCE’s resources to do their homework: for classes like art education, literature, and history, the Internet offers a lot of additional material. Supported by mentors, kids develop a high proficiency in finding and filtering the information they are looking for. By learning about the advantages and shortcomings of new media like the World Wide Web, video conferencing, eMail, and newsgroups, they acquire a level of media competence they will be able to use in their future life.

Compared to these media-oriented opportunities, the Crickets – along with the construction kits by Lego and Märklin – are only focused on by a few kids and mentors. The reason for this lack of interest is quite obvious: this kind of electronics and mechanics technology is not exactly what kids expect in a "Computer Clubhouse" environment. At a first glance, this has nothing to do with computers.

Consequently, in the first days of the project, most kids described Crickets as "small Lego robots" – this was a working example they knew from a demonstration last year, in which two tiny Lego models randomly moved around on the table and reacted by beeping and dancing when they identified each other by their infrared interfaces.

At this point, both kids and mentors could be ‘picked up’. Two ways have been prepared to tell them more about the Cricket microcontrollers and get them interested and involved in the project:

On the one hand, new pages on CCE’s Internet site have been created. This allowed everyone to find basic information about Crickets. Along with a few words about the author, these information pages made both kids and mentors aware of the microcontroller modules and caused some interesting eMail feedback.

On the other hand, similar information has been pinned up on the wall inside the CCE. It tells people more about the Crickets: about their origin, their structure, and the purpose of the various electronic parts on them, i.e., processor, RAM, interfaces, etc. These posters were especially suitable to get in touch with people interested in the project, as the kids and mentors could at first read some facts about it, and then felt more comfortable to ask further questions.

In addition to the existing hardware, Festo offered the CCE to provide pneumatic equipment like it is commonly used in training centers and educational environments. Their professional assortment covers a huge variety of cylinders, valves, tubes, connectors, etc., and a powerful air compressor.

As there are electromagnetic (‘solenoid’) valves available from Festo, this was a welcome supplement. Although its electrical specifications did not meet those of the Crickets, this pneumatic system had the potential to significantly extend the area for possible Cricket applications.

Together with the mechanical systems by Lego and Märklin, as well as sensors and motors of different origin, and the pneumatic equipment from Festo, the Crickets now seemed to emerge into a vision of an interdisciplinary learning system about modern technology, where microcontrollers can play a role of management and central intelligence.

In order to learn about the kids’ previous knowledge in basics of electronics, mechanics, and logic, the school curricula of the 6th to 10th grades have been analyzed, especially for the classes of physics and mathematics. While they differ widely in terms of the depth of theory being taught, they are surprisingly similar as far as the contents itself is concerned. This fact made it quite easy to find a suitable language for discussions about the Crickets’ technology and possibilities.

After the kids and mentors had been made familiar with both the Crickets and the possibilities of Festo pneumatics, they were asked about any ideas they had in mind: "What do you think would be a nice model to be designed?" – "What should a Cricket do to control this?" – "What kind of material will we need to build it up?"

Sometimes, the ideas developed by the kids’ creativity were just overwhelming. They have all been taken seriously, and after being recorded in words and pictures, they have been discussed and analyzed together with the ‘inventors’. Some ideas have then been dropped or revised because of their high complexity. Others have been improved significantly during the discussions.

Taken from the many suggestions, here are a few sketches of examples that have been found feasible with CCE’s resources:

	This is a top view of a funfair-style carrousel, the idea for which came from an 11-year-old girl. It could be built using elements from Lego or Märklin. The intention is that little dolls may ride the carrousel, and a Cricket can control the action so that it stops from time to time to let other dolls get on, then restart to turn the carrousel forward and backward, perhaps in random intervals.
The carrousel could be powered by a slow motor. As an option, there could be colorful lights on the roof which light up or blink when the carrousel is turning. Some funny music could be played as well...
	A 13-year-old boy had the idea for the following example: It is a bug-like animal creeping on a table. It moves straight forward until it feels the edge of the table. Then, it will stop immediately and start beeping. Depending on the direction of the edge, it will turn to the opposite direction while backing up a little bit. This will move the vehicle away from the edge. From this new position, it will restart the procedure of moving ahead until it detects an edge on any side.
The vehicle could be built from Lego Technic elements. Reflective sensors that could be used to ‘see’ the table edges are also available from Lego. The Cricket will most likely use all its input and output interfaces in this application, as two sensors and two actors are needed to perform the actions.
	The next example is based on ideas from two girls aged 12 and 14. It shows a house with a garage. On the windows, there are shutters that can open and close automatically according to the ambient light: If the sun shines (simulated using a flashlight), the shutters will close.
A light sensor could tell the Cricket about the light, and the shutters may be powered by Lego micro-motors or Festo pneumatic cylinders, whichever fit best. A similar action is performed by the garage door: it will open automatically when a car (with its headlights turned on) approaches from outside. After a given time, the door will close again.
	The Free-Climber: This is probably the most complicated Cricket application, as far as its mechanical complexity is concerned. Designed by a team of mentors, it is a pneumatic-powered device, climbing up and down a vertical rope, controlled by a Sony TV remote via the Cricket’s IR interface. The basic idea is to use two independent clamps to cling to the rope, and a contraction mechanism between two arms that creates a snake-like movement.
When realized with Lego elements and Festo pneumatics, the clamps and the contraction elements must be powerful enough to lift up the weight of the whole construction, including cylinders, solenoid valves, the Cricket, and the supply cables for air and electrical power supply (24V for the valves).
	A 12-year-old girl had the idea for this hide-and-seek game: A Cricket-controlled robot should locate a prepared bait and move towards this target, or follow a moving target. Actually, very similar applications have been suggested by several kids – one boy called it the automated version of the egg-seeking procedure at Easter.
If the bait is prepared so that it sends out infrared light, a Cricket on the robot will find out the direction towards the bait by calculating the difference between the readings of two infrared detectors mounted at an angle. As a basis on which to discuss further (more complicated) possibilities with mentors and kids, two more ideas have been added:
	In a pinball game, four pneumatic cylinders could be used to move the flaps independently. The Cricket could get the information about the exact location of the ball from either inductive sensors or contacts near the flaps. If the value range of the sensors were significantly different, the Cricket could locate the ball at four different places, even with its limit of only two input ports.
For the output, however, things will be more complicated: not only has the 9V Cricket output to be amplified to 24V for the magnetic valves, but also the connection of four valves to the two Cricket output ports will be a challenge. The pinball game could feature a manual mode, allowing a competition of a human user versus the automatic Cricket control.
	To add even further technologies to the vision of a multi-technology learning system, a feedback option over the Internet could be implemented: A Web camera would take a live image of a scenery with a Cricket application and transmit this image of real action into another place anywhere on the world.
On the one hand, mentors and kids in Computer Clubhouses on different continents could cooperate in real time to build up Cricket applications. On the other hand, if it was possible to launch Cricket commands from a Web server program, a remote user could even control what can be seen on the Web camera image! This would mean a closed-loop control of Crickets over the Internet.