Appendix

A  Presentation Slides

After the completion of the practical work on the diploma thesis, this presentation has been given to professors and students of the department.

B  Program Code Listings

For the models that have been created to test the Crickets’ extended abilities, the program source code is provided in this section. It has been explained where necessary. 

C  Glossary

Technical terms and abbreviations that have been used in this documentation are listed in the glossary. Each of them has been explained in a few words. 

D  Literature and Links

This is a compilation of the literature that has been quoted in the documentation. In addition, some links to Web sites have been added, where further information can be found. 

A Presentation Slides 

	These presentation slides have not been included as GIF files due to their size (200 by 200 mm at 300 dpi).     However, the complete set of slides may be downloaded in PDF format at the end of this page.

B Program Code Listings

 - Model "Oil Pump"

To the left, there is a screen print of the control program as it has been implemented in GrafLogo. The desired endless loop has been created using a condition that will never become true.     The lines below show the plain Cricket Logo program for the same functionality.  to pump  loop [    a, thisway on    wait 100    a, off    wait 100   ]  end

 - Model "Grasshopper"

global [a] 

to jump 
loop [ 
  seta ir 
  wait 1 
  seta ir 
  if  a = 153  [ both ] 
  if  a = 155  [ bjump ] 
  if  a = 156  [ fjump ] 
  if  a = 152  [ rear ] 
  if  a = 154  [ front ] 
  wait 1 
 ] 
end 

to both 
  ab, thisway on 
  wait 2 
  ab, off 
end 

to bjump 
  a, thisway on 
  wait 1 
  b, thisway on 
  wait 1 
  a, off 
  wait 1 
  b, off 
end 

to fjump 
  b, thisway on 
  wait 1 
  a, thisway on 
  wait 1 
  b, off 
  wait 1 
  a, off 
end 

to rear 
  b, thisway on 
  wait 2 
  b, off 
end 

to front 
  a, thisway on 
  wait 2 
  a, off 
end

 - Model "Free-Climber"

to climbup 
  b, thisway on wait 8 
  a, thisway on 
  b, off wait 8 
  a, off 
end 

to climbdown 
  a, thisway on 
  b, thisway on wait 8 
  a, off 
  b, off wait 8 
end

D Glossary

Acrobat Reader

Program / Plug-In by Adobe, necessary to view PDF files in a separate window or within the browser, respectively. The Plug-In version can be integrated into the Web browser software to display PDF files within the browser’s window. Both Acrobat versions are available from Adobe free of charge.

Beta

Pre-release stage of a product. This is the time when you give the program to selected people and ask them to test it for bugs and usability.

Browser

Software that is used to navigate through the World Wide Web, an Intranet, or local file systems. It analyses hyperlinks and commands embedded in HTML documents, and uses this information to format and display the contents of those documents.

Cache

Temporary data storage using either CPU, RAM, or local hard disk. It holds some lately viewed data and speeds up the loading time if the same data is to be used again.

CCE

Computer Clubhouse Esslingen. An institution of the Softwarelabor at the Esslingen University of Technology. CCE is embedded in the Computer Clubhouse Network.

Chat

On the Internet, chatting means that two or more people have a virtual conversation under near real-time conditions: They see a line of text written by a partner and immediately reply to this by typing a message of their own. Compared to eMail, this is faster and less formal. If eMail is the fax machine, chatting is the telephone.

CPU

Central Processing Unit. As the ‘mind’ of a computer, it does all the calculations necessary to execute the program code. Surrounded by memory and interfaces, the CPU can interact with the user and connected peripherals. 

Duplex

"Two-way": Communication can take place in both directions. While in half-duplex mode, the partners alternate at transmitting information, full-duplex means that both of them can transmit and receive at the same time (like on the telephone). 

EEPROM

Electrically Erasable Programmable Read-Only Memory. Special kind of ROM that can be rewritten several times. Compared to RAM chips, EEPROM is very slow but can store the contained information for years without power. 

Festo

Among other products, the Festo company designs and produces pneumatic systems and accessories. Festo provided the CCE with the pneumatic equipment that has been used in this project.

FHTE

Abbreviation for: Fachhochschule Esslingen, Hochschule für Technik – Esslingen University of Technology. 

Fischer

Company producing the "fischertechnik" toy system, which basically contains plastic bars. These are assembled in a tongue-and-groove manner and features many special parts for building up complex models of realistic functionality. 

Frame

Since the year 1997, all new browser software can subdivide their display window into several areas. Although their borders are not necessarily visible, these areas are called frames. It is popular to display a navigation bar in the left or bottom part of the screen. However, new generations of hand-held computers and TV add-ons (‘set-top boxes’) are being developed at this time, which will not support frames (and no JavaScript, either). This was the reason for not using frames on the Web pages accompanying this documentation. 

GIF

Graphics Interchange Format. Popular file format for images that are embedded in HTML documents. It uses lossless compression to create fairly small files of high quality. While supporting only 256 different colors in a file, it can treat one color as transparent, so you can see the browser’s background color though those areas. 

Half-duplex

See duplex. 

HTML

Hypertext Markup Language. A hypertext document contains words or images, which are linked to other texts or resources. These ‘hot’ areas are called hyperlinks. The way how these and other features are inserted into the texts is described by HTML. The files are still ordinary text files that contain so-called tags. To identify them as hypertext documents, their file name extension is ‘.htm’ or ‘.htm’. Since the World Wide Web has been invented, HTML has evolved into the standard language for Internet documents. 

HTTP

Hypertext Transfer Protocol. As a prefix to an Internet address (URL), ‘http:’ tells the browser application how to handle the desired document. There are other protocols as well, e.g., ‘https:’ (Secure HTTP) and ‘ftp:’ (File Transfer Protocol). 

Hyperlink

See HTML. 

IR

Abbreviation for infrared. Infrared radiation has a wavelength that is slightly lower than that of visible light. Like TV remote controls, Crickets use wireless communication via infrared light to share data with each other. They are also programmed by IR transmission. 

ISO

International Organization for Standardization, Geneva, Switzerland. Develops international norms and standards. 

JavaScript

Scripting language developed by Netscape as an open standard to be integrated in HTML code. Interpreted while being loaded, the scripts interact with the browser software and the document in which they are embedded and add a lot of features to plain HTML. Since 1997, all new browsers support JavaScript. However, new generations of hand-held computers and TV add-ons (‘set-top boxes’) are being developed at this time, which will not support JavaScript (and no frames, either). This was the reason for not using JavaScript on the Web pages. 

Lego

The Lego Company has become famous for their toy system based on colorful plastic bricks. "Lego Technic" adds a lot of special parts to this system, allowing to create functional models that can even be powered by electric motors. Lego intends to design a commercial microcontroller system to integrate robotics applications into their palette of products. 

Märklin

Founded in 1859, Märklin is one of the most experienced companies in metal toy manufacturing. Having always been up-to-date, Märklin is nowadays famous for their pioneer work on digitally controlled model railways. The Märklin Metall construction system is based on the "Meccano" kits patented in 1907 by Frank Hornby, England. 

PDF

Portable Document Format. A compressed file format that is popular to distribute printable information on the Internet or disks. While text and line art is stored in resolution-independent vector format, images are reduced in resolution and compressed to be included in PDF. The Acrobat software needed to read the files is available free of charge. This documentation is also published in PDF format. 

Plug-In

Software module which can be integrated into a browser. It extends the browser’s abilities so that other than the standard file types can be viewed within the browser window. Another kind of browser extensions are stand-alone programs that are called by the browser when trying to display non-standard files. These are called helper applications and display the contents in their own windows. 

ROM

Read-Only Memory. In contrast to RAM, the information stored in ROM chips cannot be deleted or replaced. An exception to this definition is EEPROM. 

Search Engine

Database service on the WWW. Most search engines browse the Internet at night and store the information they can find in a database of key words. This database can be queried by anybody’s browser software to look for information sources. 

Softwarelabor

An institution at the Esslingen University of Technology (see FHTE). The Computer Clubhouse Esslingen is one project within the Softwarelabor. 

URL

Uniform Resource Locator. The unique address of a document on the Internet. E.g., the URL for the CCE’s homepage is http://www.cce.fht-esslingen.de, where the first part (before the double slash) tells the browser software what kind of connection to establish. There are also URLs starting with ‘https:’, ‘ftp:’, or ‘gopher:’. 

Vias

On a printed circuit board with two or more layers: Connectors between layers. 

Web

Short form for World Wide Web (see WWW). 

WWW

World Wide Web. Refers to the graphical part of the Internet, which the user can browse or ‘surf’ by following hyperlinks embedded in Web documents (see HTML). 

ZIP

Compressed file format. ZIP is the most popular format for compressing data on the Internet. Compression ratio varies significantly depending on the kind of data to be compressed. Text files can be compressed very well, while GIF images for example are already compressed, so the ZIP compression will hardly reduce their size.   

E Literature and Links