I write, therefore I am
With this variation on a famous statement by the philosopher Descartes, I would like to express that the act of writing about what happens in my life is important to me.
News tickerThis evening at TkkrLab, I decided to further experiment with the Bluetooth communication. For this reason, I took the code of the IJduino cp437 program and first modified it to make it display the text to move from right to left at a fixed rate. Next I started experimenting with a method to read a new text from the serial interface, which is connected to a Bluetooth HC-06 module. The readBytesUntil method on Serial seemed the way to go, where the first paramter is given the value 10 for the newline character. The working program: newsticker.ino. Using the Arduino bluetooth app, I could enter a new text in the IJduino news ticker program. Next I wanted to also be to send a text from my netbook. Last week, I already tried to enable Bluetooth on my netbook. Now, I tried to use a Bluetooth stick that I bought a long time ago. I opened it up (just by removing a piece of tape holding it together, because it had already fell apart), and found the number BC04, which seems to indicate it is a Taiyo Yuden® Bluetooth BC04 External Bluetooth USB device. I inserted it and experimented with some bluetoothctl commands. I managed to get a /dev/rfcomm0 device and wrote a small C++ program to write the text Hallo Frans to the given device, which when executed did cause the text to be displayed on my IJduino. (I could also have used echo 'Hallo Frans' >/dev/rfcomm0 command, I realized later.) I still would like to find out how I could connect to the HC-06 module without having to give all the bleutoothctl commands.
I also tried to build my Acorn Atom emulator, which I succeeded to do after some modifications to the make file with respect to include directories and dependencies (make depend did not work). When I executed it, a window displayed, and a lot of messages about illegale opcode, because the Acorn Atom Roms were not included in the start-up directory. I must have them somewhere or see if I can use the Acorn ROMs.
Monday, July 25, 2016
Sunday, July 24, 2016
TetemI visited the TETEM art space. I first looked at the exhibition Gogbot Tribute to Remko Scha. I enjoyed listen to and looking at The Machines by Remko Scha. I also liked "No Noise II" by Jochem van der Spek. Next, I looked at Multi Solo: The Rhythm Painter. I liked the music of The missile knows where it is by Nils Mühlenbruch. I was not very impressed by the three video and sound works under the artist name microseq of Pandelis Diamantides. Finally, I looked at the exhibition The Rhythm Painter: Shape Your Identity with the Shape your identity installation, a machine that makes music and images (appearantly not working when I was there) based on a fingerprint scan. You can also turn some knobs and push some buttons to change the music. But the effect of this seems to be minimal. Nevertheless, I enjoyed playing with it. This time all the exhibition rooms did have something with sound in it.
Star Trek: BeyondThis afternoon, I went to see the movie Star Trek: Beyond. To be honest, I was a little disappointed. On positive point that I have to make is that the way in which Zachary Quinto portraits Spock is becoming more like how Leonard Nimoy portraited him. I guess, I am disappointed because this movie looks too much like all other superhero action movies that are around today. There are only dialogues that go a little deeper, such as the moment that Spock becomes philosophical about death.
Wednesday, July 20, 2016
A, a novelThis morning, I finished reading a, A Novel by Andy Warhol, which I started reading on April 18, 2014, four days after I bought it on April 12. The book contains the transcript of tapes that Andy Warhol recorded of Robert Olivo talking with others. Nevertheless, pages 344-345, contain some of the most revealing statements ever made by Warhol in public about his inability to feel happy, while he is being interviewed by Joe Campbell, in the book refered to as Sugar Plum Fairy, his nickname within The Factory. One of the other persons, Billy Name, in the book, just died yesterday. I still have many sheets of notes that I have to add process, so in a sense I am not yet finished reading this book. TkkrLab, I connected a HC-06 Bluetooth module to my IJduino with a 1KΩ and a 1.8KΩ resistor to bring the 5V signal from TXD on pin 3 of the Atmega328 down to about 3.3V for the RXD pin on the HC-06. For this I connected the 1KΩ resistor between pin 3 and a free row on the breadboard and the 1.8KΩ resistor between pin 7 (VCC) and the same free row. From this row there goes a wire to the RXD pin of the HC-06. See picture. After having this all connected and checked twice (earlier, I checked the resistors with a digital multimeter), I switched it on. A small led on the HC-06 started blinking and the IJduino performed as expected displaying a temperature graph. I first tried to enable Bluetooth on FJF2, my netbook, but that did not work out. Then I decided to find some Android app bluetooth app for my tablet. After some tries, I installed Arduino bluetooth from Giumig Apps, paired with the HC-06 and switched to terminal mode and saw the output from the Serial.print() calls in thermgraph.ino. Mission completed.
Temperature graphThis morning, I used my IJduino with thermgrap program to record the temperature changes, after I opened the door and windows. As one can see, the temperature dropped quickly and remained stable for some time. When It went up agan (around white line), I closed the door and window. And the temperature went gradually up again. Around the yellow line, I let the digital thermometer hang freely in the air, to see if that made some difference. I switched of my PC for some time and later switched it on again, after which the temperature started to rise again. Maybe because of warm air flowing along the thermometer which was hanging over the edge of the table under which the PC is standing. I think, I will repeat the experiment again tomorrow with the thermometer in a different location, further away from the PC. The graph show to the right was drawn by hand and might contain errors. I am already thinking about a better method for recording the temperature over a longer periode of time.
Sunday, July 17, 2016
thermgraphIn the evening, I finished the thermgraph.ino program for the IJduino. The IJduino is an Arduino like device with an eight by eight led display. It requires a DHT22 temperature and humidity sensor to be attached. The program will show a graph of the temperature of about the past half hour. I want to use it to determine when to close the door and windows when in the morning (during the summer time) I open them to reduce the temperature inside, because at some point the temperature outside will get higher again and keeping the door and windows open is of no use. (Some people open the windows during the hotest time of the day to enjoy the cooling effect of the blowing wind, but by doing this, they actually might increase the heat inside for the rest of the day and especially the night when they want to close the windows to keep mosquitoes outside.) Last Tuesday, I started developing this program while at TkkrLab. Someone suggested to install CuteCom and use an additional USB cable to connect to the communication ports of the Atmega328 chip, such that I could use Serial for debug output. Someone suggested I first check if it was working with the DHT-sensor-library. It did. I studied the library and decided to implement my own communication with the DHT22 sensor to understand how it works. After having finished the program, I uploaded it to FransFaase/ijduino and send a pull request to IjHack/ijduino after I made repository up-to-date with upstream. The pull request has been merged.
Three bookAt 11:42, I bought the following three books from charity shop Het Goed:
Dividual NotebookIn the evening, I ran into a man who I know since 1981. This happens about once every five years. He too has been writing diaries for a long time and continueing to do so. He was together with Brigit Egging, who graduated from the AKI in 1984 and now works as an artist in Ireland. This summer she is back in Enschede and working on a project called Dividual Notebook.
Tuesday, July 12, 2016
Komputerstrukturen 3 and 3aJust recently, I studied some photograph taken at an exhibition at the tenth floor of the Neudeflat organized by Utrechtse Kring with works by Peter Struycken, when I noticed that Komputerstrukturen 3 and 3a were included. This is the only photograph I know of these works allowing me to resolve some issues with respect to reproductions of these works in various publications. Some part of Komputerstrukturen 3a is obstructed by an Structuur sculpture from 1986, which makes it impossible to make a final verdict.
Compared to the design as given in the item AB15700, Komputerstrukturen 3 contains one difference: In row 8, column 4 the work has a white square, where the design had a black square. Which means that it seems that there are three anomalies (under the assumption that each two by two square should have had two white and two black squares according to the input given to the program that was used) in the work:
Compared to the design as given in the item AB15701, the visible part of Komputerstrukturen 3a has one difference: In row 50, column 29 the work has a black square where the design has a white square. It appears that the reproduction of the work in Recente schilderijen (1970) is equal to the design AB15701 except for the same differences with the work, suggesting that this reproduction is based on the work. If this is the case, than it is likely that the obscured part of the work is probably also equal to the design. Which means that the work seems to have the following three anomalies:
Sunday, July 10, 2016
Gerrit Rietveld AcademieI went to Amsterdam, where I arrived around half past 11. I first went to bookshop Scheltema. I bought one book as a present for Meindert. Next I went to Het Martyrium where at 13:27, I bought the book Alan Turing's Systems of Logic: The Princeton Thesis edited by Andrew W. Appel written in English published by Princeton University Press in 2014, ISBN:9780691164731, for € 7.00. Just before two o'clock, I arrived at Gerrit Rietveld Academie, where I met Meindert and some of his family and friends. We met there as part of his birthday celebration and also see the finals exhibition of the students. I would like to mention the following students:
Wednesday, July 6, 2016
Stil.l.leven02This morning, I bought the work Stil.l.leven02 by Annejet Riedijk. I met her at the AKI and brought the work home after having signed the purchase agreement. I am very happy with having bought the work. 9789068251654, from charity shop Het Goed for € 2.50.
AKI: books and workThis afternoon, Andy and I visited the last day of the AKI Finals 2016 at the AKI. I met Ilse Löbker and received two of her books, which she had hand made for me. These are:
JellyfishThe tweet Will each jellyfish in this GIF eventually end up where it started? with a GIF by Frédéric Vayssouze-Faure encouraged me to write a program to analyse this GIF. Of course, as there are only a finite number of states, at some point all jellyfish will be at their starting location. But how many swim movements will it take. I used GIF maker to retrieve the movements. I already had noticed that there were three types of swim movements that were repeated over and over again. I encoded these in the program with the characters '>', '<', '^', 'v', and '|'. The latter I used to replace '^' and 'v' when I realized that it is always possible to derive which one should be used. The program quickly found that after 6192 swim movements all jellyfish have returned at their original location. Vayssouze-Faure placed the remark: "If I had the time I would check if one of them can reach the bottom from the top…" After 23 swim movements the first jellyfish from the fifth column arrives at the top left corner. After 197 swim movements there are six jellyfish from the bottom at the top row. This is the configuration using hexadecimal digits from the row and the column:
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
If we look at where the jellyfish each time the three swim movements have been performed, it turns out that there are eleven different sequences, which when marked with the letter 'a' to 'k', results in the following table:
a a a a a a a a a a b a c b a c a a a a a a d a a a c c b c c b a a a a d d d a c a a e e c a a a a a a a a a a e a c a a c a c a a a a a a f a e f e e e a a a a a a a f a f f a a a a e a c a a f f a f f a f f a a a a a a a a a a f a f f a a f a a a a a a a f g a a a a a a a a a a a a a g a g a a a a a a a a a a a a a a a g a a a a a a a a a h i i h a a a a a a a a a a h h i h h i a a a a a a h a a h a j h h h a a a a a a a a a h a k j h j h h a a a a a a h a k a k j h h h h a a a a a a a a h a k h a h h a
There are six sequences ('b', 'd', 'g', 'i', 'j', and 'k') with a length of 12 swim movements (where the letter of each sequence appears four times in the table), a sequence ('e') of length 24, a sequence ('c') of length 36, a sequence ('f') of length 48, and a sequence ('a') of length 516. The least common multiplier of the lengths is 6192. Actually, this is the least common multiplier of 516, 72, and 48. The real big question is if there exists a combination of three swimming patterns with an even larger repeat length. It seems that the jellyfish never make a complete turn from one swimming pattern to the next. (I have not verified this with the program.) It seems a good requirement to imposse on combinations of swimming patterns. Of course, one could also ask this question for smaller sized squares (or rectangles) and with different number of swimming patterns.
Trip to China 2010
-- contact -- Frans
My life as a hacker
The Art of Programming
HTML to LaTeX
eXtreme Programming Hamilton cycles