1 | <?php |
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2 | $seiten_id = 'lernprojekte'; |
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3 | $version = '$Id'; |
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4 | $titel = 'Study projects'; |
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5 | |
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6 | require '../lib/technikum29.php'; |
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7 | ?> |
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8 | |
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9 | <h2>Study projects</h2> |
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10 | |
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11 | <h3 id="Q1"> technikum29 supports school projects</h3> |
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12 | |
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13 | <p>Microcontrollers revolutionize |
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14 | and influence next to everything. How can schools participate on these |
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15 | developments and perform successful and interesting projects?<br> |
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16 | Fife pupils of Q1 (12th year in school) of the Albert-Einstein secondary |
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17 | school were looking for a suitable idea for their so called "project |
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18 | week". This project should be connected to mathematics, physics and/or |
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19 | computer science. This is where the technikum29 got involved. The idea |
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20 | the pupils came up with was to connect technology from the 1950s with |
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21 | modern equipment of 2012. Communication spanning time and technology.<br> |
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22 | <div class="box left"> |
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23 | <img src="/shared/photos/kommunikationstechnik/arduino1.jpg" width="303" height="189" /> |
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24 | </div> |
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25 | <p>Traditionally such projects required knowledge only accessible to |
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26 | computer scientists, engineers and the like. Often they had to spend |
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27 | weeks of reading data sheets, writing cryptic assembly code etc. How |
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28 | things have changed! Since 2009 a cheap and versatile module named |
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29 | "Arduino" is available - a controller based on the well known ATmega |
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30 | 328 chip featuring 32 kB of memory. Arduino boards are designed not |
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31 | for the expert but for the layman and are the perfect base for |
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32 | creative people, artists, designers etc. |
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33 | <br> |
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34 | This project focuses on connecting computers to the "real world". The |
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35 | small Arduino board can be programmed to be used as an interface for |
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36 | nearly everything. The pupils decided to connect an early fax machine |
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37 | (a Siemens KF108 made in 1956) to a modern PC. <br> |
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38 | This fax machine is based on a rotating drum which holds the sheet of |
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39 | paper to be transmitted to the receiving station. The picture is |
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40 | scanned in a spiral movement by a photodetector that slowly moves in |
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41 | parallel to the axis of the drum. Of course, this is incompatible with |
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42 | more recent fax machines. |
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43 | |
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44 | The Arduino was planned to act as the interface between this historic |
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45 | device and a modern PC. Thus the pupils first had to learn how to |
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46 | program such a micro controller which turned out to be quite difficult |
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47 | for non-programmers. Nevertheless the software approach has its |
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48 | advantages: It is more easily debugged compared with a traditional |
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49 | hardware based interface. Thus it only took a single week to program |
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50 | and interface the Arduino board to the Siemens fax. |
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51 | |
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52 | <div class="box center"> |
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53 | <img src="/shared/photos/kommunikationstechnik/kf108+laptop.jpg" width="700" height="438" /> |
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54 | |
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55 | <p>The fax machine generates an auido signal with a frequency of 1.5 kHz |
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56 | denoting black pixels to be transmitted. To convert this into a binary |
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57 | signal with a 5V level an amplifier circuit is needed that is followed |
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58 | by an RC-combination. In addition to that a synchronization signal is |
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59 | necessary to signal the start of a new line being scanned. This is |
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60 | generated utilizing a reed-contact that is triggered by a so called |
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61 | "super magnet" that has been glued onto the axis of the scanner drum. |
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62 | The reed-contact thus generates a signal for every revolution of the |
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63 | drum which corresponds to a single line being scanned.<br> |
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64 | |
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65 | The control program for the Arduino was developed by the pupils (and is |
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66 | <a href="/de/lernprojekte/arduino-projekt-programme/" class="go">online avaliable |
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67 | in our repository</a>). It allows the picture being scanned, a historic Mickey-Mouse drawing, to be transferred to the PC |
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68 | where it is displayed slowly line by line with good resolution. |
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69 | |
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70 | The experiment was a full success and will inspire future projects. |
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71 | |
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72 | <p class="small">*) Arduino: The name of this board derives from King "Arduino of |
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73 | Ivrea" who lived in medieval times in northern Italy where the |
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74 | controller was developed.</small> <br> |
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75 | |
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76 | <h3>Siemens computer for demonstration</h3> |
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77 | |
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78 | <div class="box center"> |
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79 | <img src="/shared/photos/rechnertechnik/siemens-democomputer.jpg" alt="Siemens-Democomputer" width="700" height="587" class="nomargin-bottom" /> |
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80 | <p class="center"><b>Siemens computer</b></p> |
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81 | </div> |
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82 | |
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83 | <p>The demonstration model shown above was built in 1973 by Siemens (Germany). It |
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84 | was used as an educational tool for technicians and engineers. The large |
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85 | machine on the right was built in rather high numbers for computer science |
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86 | courses and the like. Even today it can be used to show the basic principles of |
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87 | instruction processing, internal cycles etc. Its short word length of only 4 |
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88 | bits is sufficient for this.<br> |
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89 | The program can be setup on the left by use of plugs containing various binary |
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90 | values representing the instructions of the machine. The "computer" can be |
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91 | operated in either one of two modes: cycle mode or instruction mode. In |
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92 | addition to that its clock cycle time can be set arbitrarily or single step |
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93 | mode can be selected. 126 incandescent lights show the data flow through the |
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94 | registers, the operation of the control circuitry, the arithmetic/logic unit |
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95 | and the memory locations.<br><br> |
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96 | |
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97 | The demonstration model represents a bit-parallel program controller computer. |
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98 | The currently implemented program adds to binary values. It demonstrates that |
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99 | even short word lengths do not necessarily restrict the range of values that |
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100 | can be processed by such a machine.<br> |
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101 | |
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102 | |
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103 | |
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104 | It is a truly wonderful machine that displays the elementary processes taking |
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105 | place in every computer even today.</p> |
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106 | |
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107 | |
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