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2        $seiten_id = 'lernprojekte';
3        $version = '$Id';
4        $titel = 'Study projects';
6        require '../lib/technikum29.php';
9<h2>Study projects</h2>
11<h3 id="Q1"> technikum29 supports school projects</h3>
13<p>Microcontrollers revolutionize
14and influence next to everything. How can schools participate on these
15developments and perform successful and interesting projects?<br>
16Fife pupils of Q1 (12th year in school) of the Albert-Einstein secondary
17school were looking for a suitable idea for their so called "project
18week". This project should be connected to mathematics, physics and/or
19computer science. This is where the technikum29 got involved. The idea
20the pupils came up with was to connect technology from the 1950s with
21modern equipment of 2012. Communication spanning time and technology.<br>
22<div class="box left">
23        <img src="/shared/photos/kommunikationstechnik/arduino1.jpg" width="303" height="189" />
24       </div>
25<p>Traditionally such projects required knowledge only accessible to
26computer scientists, engineers and the like. Often they had to spend
27weeks of reading data sheets, writing cryptic assembly code etc. How
28things have changed! Since 2009 a cheap and versatile module named
29"Arduino" is available - a controller based on the well known ATmega
30328 chip featuring 32 kB of memory. Arduino boards are designed not
31for the expert but for the layman and are the perfect base for
32creative people, artists, designers etc.
33 <br>
34This project focuses on connecting computers to the "real world". The
35small Arduino board can be programmed to be used as an interface for
36nearly everything. The pupils decided to connect an early fax machine
37(a Siemens KF108 made in 1956) to a modern PC.   <br>
38This fax machine is based on a rotating drum which holds the sheet of
39paper to be transmitted to the receiving station. The picture is
40scanned in a spiral movement by a photodetector that slowly moves in
41parallel to the axis of the drum. Of course, this is incompatible with
42more recent fax machines.
44The Arduino was planned to act as the interface between this historic
45device and a modern PC. Thus the pupils first had to learn how to
46program such a micro controller which turned out to be quite difficult
47for non-programmers. Nevertheless the software approach has its
48advantages: It is more easily debugged compared with a traditional
49hardware based interface. Thus it only took a single week to program
50and interface the Arduino board to the Siemens fax.
52<div class="box center">
53        <img src="/shared/photos/kommunikationstechnik/kf108+laptop.jpg" width="700" height="438" />
55<p>The fax machine generates an auido signal with a frequency of 1.5 kHz
56denoting black pixels to be transmitted. To convert this into a binary
57signal with a 5V level an amplifier circuit is needed that is followed
58by an RC-combination. In addition to that a synchronization signal is
59necessary to signal the start of a new line being scanned. This is
60generated utilizing a reed-contact that is triggered by a so called
61"super magnet" that has been glued onto the axis of the scanner drum.
62The reed-contact thus generates a signal for every revolution of the
63drum which corresponds to a single line being scanned.<br>
65The control program for the Arduino was developed by the pupils (and is
66<a href="/de/lernprojekte/arduino-projekt-programme/" class="go">online avaliable
67in our repository</a>). It allows the picture being scanned, a historic Mickey-Mouse drawing, to be transferred to the PC
68where it is displayed slowly line by line with good resolution.
70The experiment was a full success and will inspire future projects.
72<p class="small">*) Arduino: The name of this board derives from King "Arduino of
73Ivrea" who lived in medieval times in northern Italy where the
74controller was developed.</small> <br>
76<h3>Siemens computer for demonstration</h3>
78<div class="box center">
79        <img src="/shared/photos/rechnertechnik/siemens-democomputer.jpg" alt="Siemens-Democomputer" width="700" height="587" class="nomargin-bottom" />
80                <p class="center"><b>Siemens computer</b></p>
81        </div>
83<p>The demonstration model shown above was built in 1973 by Siemens (Germany). It
84was used as an educational tool for technicians and engineers. The large
85machine on the right was built in rather high numbers for computer science
86courses and the like. Even today it can be used to show the basic principles of
87instruction processing, internal cycles etc. Its short word length of only 4
88bits is sufficient for this.<br>
89The program can be setup on the left by use of plugs containing various binary
90values representing the instructions of the machine. The "computer" can be
91operated in either one of two modes: cycle mode or instruction mode. In
92addition to that its clock cycle time can be set arbitrarily or single step
93mode can be selected. 126 incandescent lights show the data flow through the
94registers, the operation of the control circuitry, the arithmetic/logic unit
95and the memory locations.<br><br>
97The demonstration model represents a bit-parallel program controller computer.
98The currently implemented program adds to binary values. It demonstrates that
99even short word lengths do not necessarily restrict the range of values that
100can be processed by such a machine.<br>
104 It is a truly wonderful machine that displays the elementary processes taking
105place in every computer even today.</p>
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