Sunday, December 1, 2024
Advent of Code
Yesterday, I made some preperations to join Advent of Code this year and try to get up at six in the morning every day till Christmas. I am going to use the literature programming with MarkDownC again. My progress can be followed in the repository AdventOfCode2024. Some people on the leader board:- Justin Arnold
- Shen Li: aoc2024
- Blake: adventofcode
- Nordine Lotfi
- tckmn
- Neil Thistlethwaite: Advent of Code 2024 Day 1 - Top 20 Finish!
- ben: advent-of-code-2024
Going into the city
I first went to the Media Markt show where I came across a PNY 512GB Attaché 4 USB 3.1 flash drive for just € 17.99. I could not resist the offer and decided to buy it. (The other product for which I came to the shop, happened much cheaper than I had expected.) Next, I went to bookshop Broekhuis where at 15:23:47, I bought the book Ooggetuigen: bezoekers vertellen over de collectie van het Bonnefanten written by Maria Barnas, Abdelkader Benali, and Sarah van Binsbergen, written in Dutch, and published by Bodosz Uitgevers in 2020, ISBN:9789082313116, for € 8.95. From there, I went to Rijksmuseum Twenthe, which had an open day with free entry. I first went to see the exhibition Chasing The Dot again and I sat for some time in the installation Chasing The Dot. I took some pictures of the books of Philip Vermeulen that were on display. I noticed that some had been moved. I looked around the back of the museum that was closed the last time we were there. I did not find the Falaises près de Pourville painting by Monet. It is possible that it has been loaned for an exhibition. I also came across the Beam Waver work by David Scheidler that is part of the exhibition Gogbot x RMT. I missed the two times before I saw this exhibition because it is a bit in a corner where it was not visible. I also saw that the exhibition PLANETART ARCHIVES X Kees de Groot 1978-2003 had been removed. They were selling posters and books at strongly reduced prices. I bought a poster of Falaises près de Pourville for one Euro.Saturday, November 30, 2024
Link
Wednesday, November 27, 2024
Laurie Langenbach
I finished reading the book Brieven, dagboeken en een geheime liefde by Laurie Langenbach, which I started reading on September 26, the day I bought it. The book is part of a large series of (auto)biographic books. The book contains a short biography, a collection of letters and diaries, and the novel Geheime Liefde (Dutch for Secret Love) by Laurie Langenbach. The novel was about her being secretly in love with the Dutch chess player Jan Timman. She did not mention his name in the novel, her debut novel, but he was quickly identified after the novel was published. The novel did not receive good reviews. There are good reasons that this was due to it strong autobiographic content written by a young woman talking openly about sexuality. I found it an interesting read and making me want to read more from her. She wrote a lot of articles for various underground and mainstream magazines. I have not found a list of everything she wrote.Sunday, November 24, 2024
Into the city
At the start of the afternoon, I went to the main venue of The Overkill Festival. It was rather quiet and I sat on one of the tables and worked a bit on this website. I also listened a bit to the SickFem “Having fun with synthesizers” workshop. I walked through the city because I wanted to look for something in a shop. I did find it, but there was a long waiting line, and I decided to come back another time or order it from the webshop. It has been a long time ago that I walked through the city center on a Sunday, but I felt it was really busy. Maybe it was due to high temperature of today, which really exception when compared with the low temperatures that we had last week. Maybe it caused by Storm Bert that is causing trouble in Ireland and United Kingdom. At Twenthe Airport has gone up to 17.4° Celsius, which breaks the previous record of 13.9° on this date in 1951.I went to Concordia where I first looked at some people playing with the Joystick. Next, I talked a bit with Kira Fröse before I listed to the artist talk of Marthe Zink and her. Some people say that art should speak for itself, but it is my experience that when artist talk about their work and how they create their works, it makes you look at the works with a different eye and it often increases your appreciation. I had not realized that combinations of the works by both artist had been placed in circle shaped spots when watched from the correct location and that the colour of the spots was related to the works, often a colour found in both works. I really enjoyed the artist talk which was organized as a talk between the two artists and the organizer.
On the way home, I saw some impressive clouds in the sky, and I took the picture shown below.
Sunday, November 23, 2024
The Overkill Festival: Day three
During the second half of the afternoon, I joined the Consensual Hacking workshop by Melanie Hoff, which due to number of participants became more of a presentation about consent. Only after the workshop, some people sat together to some 'real' consensual hacking, where, if I understand correcly, Melanie allowed others to log into a laptop through ssh. I had to go home for dinner.In the evening, I went again to the main venue, where I sat at one of the tables and talked with some of the other participants, while in the background listening to the music program. At the end of the evening, I went to the Sick&Sexy short films program with films selected by Menelas Siafakas. It was in a small screening room with fifthy seats, which (almost) filled-up completely. The following short films were screened:
- The Raspberry Reich GR (2015) directed by Menelas Siafakas.
- Love Your Cunt (2019) directed by altSHIFT ES.
- Exibidas (2021) Directed by Aló, hiperlinque, Tormenta Cósmica
- Fuck the Fascism (2016) directed by Maria Basura (Flickr). It is a kind of protest agains the human zoo of Carl Hagenbeck. The public responded with a big applause.
- No Democracy Here (2019) directed by Liad Hussein Kantorowicz. It was about political BDSM. At first I thought it was kind of joke. Later I was a bit shocked by the racism (bordering on fascism) by some of the Isarelian bystanders seen in the film. Again the screening was followed by a big applause.
- Freedom X (2022) directed by Pau Devolar Van Dragen.
Friday, November 22, 2024
The Overkill Festival: Playfull Friday
There was some snow during the night. It did cover more than last Wednesday. In our garden the ground was not totally covered. The snow was already melting, causing waterdrops to fall from the trees. From what I saw on some roads, it looked like the snow did fully cover the grount. I arrived a little early at Het Vestzaktheater (Dutch for 'the vest pocket theater') for 'Playful Friday.' This year the theme is 'Radical Joy Resistance.'At 10:16, as the opening of the day, lead by Zuraida Buter, who also acted as the curator, we stated to play with Play-Doh creating a sculpture named 'Joy' on the floor. It would stay there for the whole day.
At 10:30, Helen Kwok and Chad Toprak with a live connection from Melbourne showed things related to the theme: Sites of Resistance: A Walk Through Narm (Melbourne). It is 37°C there. They showed how people connected ribbons to the Evan Walker Bridge to show their solidariy with the people in Gaza. While walking through the city they showed places where protests and rallies were held and where playful activities were organized. They also showed pictures of these events and activities. Really an interesting way to give a talk from the other side of the world.
At 11:38, Jugar Jueguitos and Resistència VideoLúdica gave a workshop about Downpour game creation app. They are from Catalonia and Galicia, two surpressed cultures within Spain. With Downpour it is possible to create simple games without having to write code. That is why they have been using it for developing games.
After the lunch break, at 13:37, Nathalie Lawhead (Website, blog) gave the presentation A Tiny Talk About Tiny Tools. The started to talk about some old tools:
- Mario paint. The opening screen is very interactive. The drawing made sounds. Everything is moving and animated.
- Creative Writer by Microsoft, which has very bad UI design with respect to nowadays standards.
- Game Engines Database
- Tiny Tools Directory
- Cool Tools on Twich
At about 14:10, due to some technical problems, Aran Koning gave the talk sok-Worlds, sokpop and other sok-stories. He is one of the four members of the sokpop collective and he created sok-worlds, a tool to create worlds with pictures and text. He showed us some sok-worlds, among some favourites: Crousant Moon, Dysphonia and Bart's Zoo. He then continued his talk by walking through 'boring world 10' by arni.
Next, Afra Willems gave the presentation Polished vs 'Primitive' - Resistance through multilingual visual styles. She told that she was surprised when she heard that the graphics of the game Thunderbird Strike by Elizabeth LaPensée was judged as unprofessional by game critics. She noted that these critics use words like sophisticated, polished, and high-end to describe the graphics of games. Is that what makes it professional. The mainstream style is technology oriented. She felt that this was an example of colonial ideas with respect to visual styles. She mentioned some quotes from the books Monolingualism of the Other or, The Prosthesis of Origin by Jacques Derrida and Black Skin, White Masks by Frantz Fanon about the surpressed and the language used by the oppressor. She mentioned three non-mainstream games that dealt in a different way:
- Rinse and Repeat, an erotic video game from 2015, by Robert Yang made use of polished graphics like used in mainstream games.
- Terra Nova, a video game from 2019, by Maize Longboat used a pixel visual style like used in older video games.
- Thunderbird Strike, a video game from 2107, by Elizabeth LaPensée used a 'traditional' Anishinaabe Woodlands style art combined with digital techniques.
The next talk, (re-)Act through Playful Resistance in Digital Spaces was given by Jisoo Lim 임지수. The notes I took:
- Playful Digital Activism.
- Physical: Tangible connection. Sensory immersion. Sense of grounding.
- Digital: Geographical unbound. Expanded reach and inclusivity. Playful and subversive realm.
- Hong Kong protestors used Animal Crossing MMORPG to protest.
- DS: anonimous, connect on shared identies, hashtag movements.
- Where does playfulness come in? How can this look?
- Virtual march happening in Roblox (2023)
- Online Queer Parade Seoul (2023)
- Online Queer Parade Seoul Hastag activism on Instagram (2023)
- Sena (2023) computer game
- Their Garden (2024) mobile game.
Around 16:15, Claire Kwong gave her presentation Prototyping with Touch and Intimacy. where she spoke about her games which encourage people to move and touch. She askes some people from the public to play her earlier games. She explained how she arrived at her game Between. She also asked the public for ideas for games that encourage people to touch each other.
The program ended with Pablo F. Quarta playing the game The Quiet Year with the audience.
The Overkill Festival: Second evening
In the evening, I went to the main exhibition room again. There I:played the following games:- You can't win this game
- Um Al-Zaytown (Mother of Olives)
- The Bride Who Could not Stop Crying
- Ojancanu. I like the graphics, but I think I did not grasp the goal, especially when I someone else play the game.
- Gay Boy (just looked at it. I played it a little bit yesterday evening.)
- Harri Kanta
Thursday, November 21, 2024
Sauerkraut
This evening, we had our first home made sauerkraut that Conny had made from savoy cabbage and white pointed cabbage, which we have received in the harvest of Herenboeren Usseler Es. It tasted nice. So, it was quite a succesful attempt to make home made sauerkraut.The Overkill Festival: Opening night
In the evening, I went to the opening evening of The Overkill Festival. It was held again at a different location than last year. The main location is at The Performance Factory. There I saw the following works:- Aproximación a une cartogratia, a series of short documentary films by LASTESIS.
- A game called Maybe we Save the World, where you had to walk around a city and where you had to collect lights. I did not understand the goal of the game.
- A game called Sk8border
- New Suns, a projection on three walls by Antigoni Tsagkaropoulou, which did contain some nudity.
- A game called Mbombo: Dream Echoes by Sondi, which I played a bit.
- A game called To all the rocks that raised me on a small screen by Carlos Cortés. Play it online.
- The game Atuel by Matajuegos. I started the game a cloud and changed into a fox and back into a cloud.
- The installation/game Harri Kanta by Juliette Lizotte (Instagram).
- The Bride Who Could Not Stop Crying by Afrah Shafiq
- Electric Zine Maker
- I shortly joined in with Galiens Show, a audio-visual rave performance by Oliotronix and Maria Mam by moving my hand over a light sensitive cell and turning a nob as input to the music being generated.
- Dance Poem Revolution by Melanie Hoff which will print out small pieces of paper with words that you selected by stemming on arrow buttons on the ground.
- The New York Times Simulator by La Molleindusria.
- The game March Together by Simona Maiorano.
- The video Violent Violins Exposed by Babak Ahteshamipour.
- The VR game From The Main Square by Pedro Harres.
- The game Perfect World by Michael Overton Brown.
- The video Claiming Space, which I found quite interesting.
- The game Between by Claire Kwong.
- The email sending program EU CLIMA COMPLAIN by Artemis Sartzetakis with which you can send an email about climate change to one of the members of the European Parlement. I did not participate in sending an email but I did have an interesting conversation with her.
Link
Wednesday, November 20, 2024
Snow
This afternoon, it snowed again and this time stayed on the grass and on cars. I estimate that at least 1cm of snow fell. The snow that stayed did not melt away in the evening, like it did yesterday.Link
Tuesday, November 19, 2024
Wet snow
This afternoon, for some hourse there was wet snow falling from the sky. While it was snowing, some of it stayed on the grass a bit Still would not count this as snow. During the period it snowed, the temperature dropped to almost zero degrees Celcius.Sunday, November 17, 2024
Cooperative, polling operating system
I have been thinking about a tiny cooperative and polling real-time operating system that works with static, single instance tasks. ESP-IDF is based on FreeTROS, a real-time operating system for embedded devives. Although FreeTROS is called real-time, it has some dynamic behaviour due to dynamic memory allocation and interrupts. Nowadays, many peripherals are connected through serial communication busses, such as SPI, I2C, and I2S, where there are often multiple slave peripherals are connected on a bus. These peripherals often have complex operating modes that can be adjusted through control registers, and possibly also complex behaviour patterns. This has an impact on the real-time behaviour of microcontrollers that communicate with these peripherals. If you do not want to use interrupts, it means you have to use polling to see if an interaction with a peripheral has completed. If you develop an application that interacts with several peripherals, it is logical to have some kind of layering in more device oriented tasks, coordinating tasks, and more high-level tasks. If you do not use operating system like functions like queues, this results in tasks polling the completing of lower-level tasks. To avoid excessive polling, which takes a lot of resources, I have been thinking about a number of queue based approaches to avoid polling. Tasks often make use of finite-state machines, which are usually implemented with case-statements. If these are not compiled to branch tables they performance is lineair to the number of cases. To work around this, one could use functions for each of the states and cause the right function to be called for each state. This does match with the idea of tasks. I have started writing some code as an experiment: TinyCoPoOS.c. I also have been thinking about program generating the code for all the functions given a tasks declaration.Planting fruit trees
In the afternoon, I helped a bit with the planting of fruit trees at Herenboeren Usseler Es. When I arrived the others just were taking a break, because some of them already started at nine in the morning. I mostly dug holes at the places where a tree had to be planted. Twice we had some rain. The first time with some hail and at 14:30, there was a rainbow. I am looking forwards how the trees are going to grow in the coming years.Saturday, November 16, 2024
Harvest
Below a picture of the harvest (except for the 2 kilogram potatoes) that we received this morning from Herenboeren Usseler Es. (What you receive depends on how many 'mouths' you are paying for and personsl choices you make.)The picture shows:
- A bag with 2Kg of rye flour
- Two red chicories
- A savoy cabbage
- A cauliflower
- Two delicata squash
- Some lacinato kale
In the evening, I made some stamppot with the lacinato kale, two small red unions, a yellow bell pepper and some sauerkraut bacon. Conny made a salad with the outer leaves of the two red chicories.
Friday, November 15, 2024
Book
At 17:05:15, I bought the book HETHE BESTE VAN OF WIM T. SCHIPPERS written by Harry Ruhé in Dutch and English, and published by Centraal Museum in 1997, ISBN:9789073285446, from bookshop Broekhuis for € 45.00. This is a bilingual edition where the Dutch text is printed in red and the English text in green on top of each other. To read the text a transparent green and red sheet is provided in the front of the book that you have to put over the text. This book is the catalogue of an exhibition of the same name.Thursday, November 14, 2024
Exhibitions
After work, I went into the city where I visited the exhibitions at Concordia. I saw the following exhibitions:- Joystick by Madison Bycroft. I played a bit with the game but I got into the water and had some trouble getting out of it. I did not know how to exit the game. This exhibition is part of the Overkill Festival.
- Doublet #6: Kira Fröse and Marthe Zink. I felt that they really succeeded into make cohesive exhibtion when combining their art works.
- The Artist's Way with works by various mothers following the book The Artist's Way by Julia Cameron. There were some series of works that really stood out.
- It Gets Better by Tim Vischer.
- Ik kom er nu nog gewoon even echt niet uit by Björn Zielman.
Monday, November 11, 2024
Links
- On Typesetting Engines: A Programmer's Perspective
- Audio Decomposition
- Texture-less Text Rendering
- Mergiraf
Sunday, November 10, 2024
Wijlre
On the way Wijlre Conny and I stopped at the Netherlands American Cemetery and Memorial located in the village of Margraten and waled around the cemetery. We thought about the many soldiers that died during the liberation of Europe from the German occupation and how this relates to the current war in the east of Europe. We did like the design of the chapel with the window on the side.Close to noon, we arrived at Kasteel Wijlre Estate for the exhibition Maintaining Its Spirit: Collection Marlies & Jo Eyck. I found the following works noteworthy:
- Color space generator Eyck, Peter Struycken, 1999.
- 1.5 kwadraat, reliëf met anderhalf vierkant, Ad Dekkers, 1969.
- Untitled, herman de vries, 1977.
- TAP2 TAPW5, Peter Struycken, 19880-12-02.
- Claie obscure, Carel Blotkamp, 2002.
- From Cube to Cylinder, Ad Dekkers, 1968.
- Untitled, Leo Vroegindeweij, 1993.
- Kleuren van Tuinhuisje naar Goudreinet appel, Peter Struycken, 1993.
- Salami, Carel Visser, 1964.
- Broken Circle, Ad Dekkers, 1971.
- Pathway Tree and Bronze Tree, Giuseppe Penome, 1197.
- Piet 5, Peter Struycken, 1984.
- Afstemming IV, Peter Struycken, 2020.
- Dots 81 mimosa, Peter Struycken, 1981.
- Untitled, Richard Paul Lohse.
- Jacquard geweven wanddecoratie, Peter Struycken, 2008-09.
- Plant-Based, Carel Visser, 1989.
We also saw the exhibition Growing Poetics by Thierry Oussou. We in particular liked the La Poessie in one of the rooms in the attic that he had filled with branches he found on the estate.
On the way home we stopt at the McDonalds in Drosten were we ordered two McPlant meals consisting of a plant based burger with french fries and a cola. This is at least the third time I visited this McDonalds. I visited it on Saturday, September 22, 2018 with Andy and on Friday, July 29, 2010 with Li-Xia.
Saturday, November 9, 2024
Bonnefanten Museum
Conny and I visited the Bonnefanten Museum in Maastricht. We first went to see the exhibition Maintaining Its Spirit: Collection Marlies & Jo Eyck at Bonnefanten. I found the following works noteworthy to mention:- Untitled, Rob van Koningsbruggen, 1977.
- Cluster no. 16, Peter Struycken, 1971.
- Cluster no. 2, Peter Struycken, 1971.
- KTV1T.852, Peter Struycken, 1983.
- POS 18F, Peter Struycken, 1985.
- KTV kleur, Peter Struycken, 1978.
- Lnarc, Peter Struycken, 1973.
- Structuur XXXIII, Peter Struycken, 1967.
- Kleurstructuur voor bedrijfspand J. EYCK 1e Roermond, Peter Struycken, 1977.
- KTV kleur, Peter Struycken.
- 090373-1B (Plons), Peter Struycken, 1973.
- Field 47, Peter Struycken, 1979.
- Shft 25, Peter Struycken, 1983.
- SIM, Peter Struycken, 1987.
- Shft 34, Peter Struycken, 1986.
- Boulez/45k/20nov04/06-maa/28.bmp, Peter Struycken, 2005.
- Some Natural Aspects of Sculpture, Ger van Elk, 1972-2002.
- She loved her madly, Jarostaw Fliciński, 2005.
- 71-36, Jan Schoonhoven, 1971.
- Untitled, Ben Akkerman, 1983-1984.
- Wand II, Amédés Cotrrer, 1970.
- 2T, Donald Judd, 1971.
- Dubbelschilderij, Bob Bonies, 1968.
- Computerstructuur 69-II, Peter Struycken, 1969.
- Houtgrafiek nr VIII, Ad Dekkers, 1970.
- Stad, Ad Dekkers, 1960.
- Zeshoek en ruit overgang, Ad Dekkers, 1967.
- Cirkel op de middellijn omgezet, Ad Dekkers, 1968.
- Untitled, Ewerdt Hilgemannn, 1973.
- Untitled, Bart van der Leck, circa 1928.
- Serie A,B,C,D,E,F, Right Hand Left Hand, Kenneth Martin.
- square grid - complexities, herman de vries, 1975.
- Gitter, François Morellet, 1962.
- Untitled, Chris Beekman, circa 1945.
- Zwart Wit, Amédé Cortier, 1972.
- nKM V, Carel Blotkamp, 2006.
- The space between you and me, Keith Edmier, 2000.
- Tschlin, Curdin Tones, 2005.
- Far from the madding around , Dan Asher, 1996.
- On a night like this II, Mathilde ter Heije, 1998.
- Kleine Pneuma, object no. 14, Robert Lambermont, 2001.
- Regen, Carel Visser, 1985.
From the exhibition Stanley Donwood and Thom Yorke: Maps of the New World I liked:
- Unchecked, 2022.
- A Map of the New World, 2024.
From the exhibition Małgorzata Mirga-Tas: This is not the end of the road, a solo exhibition with works by Małgorzata Mirga-Tas, I found the following works to be noteworthy:
- Phenia - Sister, 2024.
- Basiawiben predale baba - Music for grandmothers, 2024.
- Roziena kiereta babakie sinkar hajtań - Roziena brushes her grandmother's beautiful hair, 2024.
- Portrait of Lalla Weiss, 2024.
- Re-Enchanting The World, a series of twelve works, which we both
found the most impressive of what we saw on this day:
- January 2022
- February 2022
- March 2022
- April 2022
- May 2022
- June 2022
- July 2022
- August 2022
- September 2022
- October 2022
- November 2022
- December 2022
- Out of Egypt, 2024.
- Out of Egypt, 2024.
From the exhbition Dream On, I found the following works noteworthy:
- A Map of Days, Grayson Perry, 2013.
- Untitled (Master of the Universe, Lee 'Scratch' Perry, 2018.
- Mommy, Sofiia Dubyna, 2023.
- Dianaland, Sofiia Dubyna, 2023.
- Diana's Monkey, Sofia Dubyna, 2023.
- Pee on Presidents, Melanie Bonajo, .
- Eight drawings, Sandra Vásquez de la Horra, 2007.
From the exhibition Collection Neutelings, I found the following painting noteworthy:
- Still Life, Henri de Fromantiou, circa 1670.
- Portrait of a Couple or a Mother and Son, Cornelis de Vos, 1600-1650.
- Family Portrait, Pieter Isaacsz, 1609.
- Census at Bethlehem, Pieter Brueghel Jonge, ca. 1605-1610.
From the exhibition Truly Wicked: The Seven Deadly Sins visualised, I found the following works noteworthy (I was getting a bit tired and filled with images):
- Herbergscène, Helen Verhoeven, 2017.
- Church I, Helen Verhoeven, 2017-2018.
- Tavern Scene, Monogrammist van Bruuswijk, circa 1535-1540.
- The World in Good Standing, Anonymouse, circa 1570.
- Allegory of Lust / Lascivia, Abraham Jansens van Nuyssen, circa 1618.
Furthermore, we walked through Studio Rossi with design of the museum building and walked around The Shooting at Watou by Folkert de Jong.
Maastricht
After we visited the museum, we walked through Maastricht taking some pictures. We brought a short visit to the bookshop Boekhandel Dominicanen, which I visited before on Sunday, July 21, 2019. It was already dark, but we took some pictures from the Sint Servaasbrug (a bridge over the Meuse river) before went to the Indonesian restaurant KapuláGa were we had the Kakanda rice table, which existsed of yellow yice, daging balado, rendang, smoor, ayam pedas, ayam opor, sate ayam, sambal goreng udang, tempe, poached egg, sayur lodeh, seasonal vegetables, gado gado, atjar, seroendeng, roedjak. We had some strawberry ice as an desert. We were very satisfied with the dinner.Thursday, November 7, 2024
Cubes from Sheet: 11 by 11
I have this feeling that there are solutions for all cubes from a sheet problems, where at least one piece can be placed into, exists where at most twelve squares are unused for cubes. In the past weeke, I have been searching for counter examples. The program that I used, took a long time to find a solution with less than thirtheen unused squares for a square of eleven by eleven squares. Yesterday, I modified my Exact Cover program to also support positions with multiple vectors. This is a generalization of the Exact Cover problem. The multiple positions are needed to restrict the number of unused squares to an exact number. When I tried this program on the elven by elven square with seven unused squares, it found some solutions within half an hour. The first solution it found was represented as (on a single line):S0_1_2_13_14_15|S3_4_5_16_17_18|S6_7_8_19_20_21|e9|e10|E11_12_23_24_25_36|E22_33_34_35_46_47|W44_45_56_57_68_69|W55_66_67_78_79_90|E77_88_89_100_111_112|e99|e110|D31_32_40_41_42_52|e30|W43_53_54_63_64_74|W65_75_76_85_86_96|E87_97_98_108_118_119|e109|e120|A28_29_38_39_50_61|Z26_27_37_48_58_59|S51_62_72_73_83_94|S49_60_70_71_81_92|K80_91_101_102_103_113|A82_93_104_105_114_115|A84_95_106_107_116_117|
This evening, I checked this solution and made the following drawing of it:
+--+--+--+--+--+--+--+--+--+--+--+ | | | |##|##| +--+--+ +--+--+ +--+--+ +--+--+ | | | | | +--+ +--+--+--+--+--+--+--+--+--+ | | | | |##| | + +--+--+ + +--+ +--+--+ +--+ | | | | | | | +--+--+ +--+ +--+ +--+ +--+ + | | | | | | | | | +--+ +--+--+ + + + +--+ +--+ | | | | | | | | | + +--+ +--+--+ +--+ + +--+ + | | | | | | | +--+ +--+--+ +--+ +--+--+ +--+ | | | | | | | | | | + +--+ + + + + + + +--+ + | | | | | | | | | | +--+ +--+ +--+ +--+ +--+ +--+ |##| | | | | |##| +--+ +--+ +--+ +--+ +--+ +--+ |##| | | | | |##| +--+--+--+--+--+--+--+--+--+--+--+
I plan to refactor the code of my Exact Cover program such that it can be more easily be called from the program finding solutions for the Cubes from Sheet problems.
Tuesday, November 5, 2024
Book
At 18:40, I bought the book Prospects 2021: Mondriaan Fonds toont talent edited by Mirjam Beerman, written in Dutch, and published by Het Mondriaan Fonds in June 2021 from thrift store Het Goed for € 1.00. Before I there, I went to thrift store Rataplan. Although it seems they have more books there, I get the impression that they sell less books. These trift stores are for profit shops.Link
Sunday, November 3, 2024
Links
Saturday, November 2, 2024
Colourful harvest
We got a rather colourful harvest from Herenboeren Usselere Es and I took a picture of a part of the harvest.In this picture there are: a small puprple cauliflower, a romanesco broccoli, a fennel, two red cabbages, a green and a orange pumpkin, and a leaf of curly kale.
Link
Friday, November 1, 2024
63 years
I was born on Wednesday, November 1, 1961 at 9:45 in the morning (CET). That means that today, I will be 63 years according to the calendar and 23011 days old. But how old am I really? The tropical year, the time that it takes for the seasons to return, is said to be 365 days, 5 hours, 48 minutes, and 45.19 seconds. Yesterday, around 15:56:26 in the afternoon, it was 63 tropical years since I was born. But the tropical year is shorter than the sidereal year, the time taken by the Earth to orbit the Sun once with respect to the fixed stars, namely 365 days, 6 hours, 9 minutes, and 9.76 seconds. That means that, today at 13:22:14 it will be 63 sidereal years after I was born. The average anomalistic year, the time taken for the Earth to complete one revolution with respect to its apsides, is 365 days, 6 hours, 13 minutes, and 52.6 seconds. That means that, today around 18:19:13 it will be 63 average anomalistic years since I was born.Double declaration?
I have been using the C progamming language (and later C++) for more than 34 years, but today I wrote something, I cannot remember having written before and it looks like a 'double' declaration of a variable:extern int counter; int counter = 0;I am big fan of encapsulation and I like clean include files that hide implementation details that are not necessary for the users of the functions given in the header file. The implementation for a certain header file depended on a global counter that I did not want to include in the header file itself, but it needed to be incremented somewhere else and initialized to zero. So, I wrote in that other location, the main file (containing the main function):
extern int counter = 0;And this resulted in a compile error, because you are not allowed to initialize a variable that is declared extern. Next, I changed the line into:
int counter = 0;Now, I got a linking error saying that the other external definition (in the C file implementing the header file that relied on the counter variable) was not defined anywhere. This is because although it is defined in the main file, it was not defined as extern and thus not visible on the outside and thus becoming invisible for the linker that combines all the separately compiled C programs into one executable. It dawned on me that if I would have placed the extern declaration in the header file, it would have worked because then during the compilation of both C programs it would have been defined as extern and in the main program I still would have been able to initialize it. Although it is not common to see a 'double' declaration in a C file, like the above, and even looks a bit confusing, it is actually somthing that is done all the time, because the C preprocessor put both declarations into the intermediate file that is compiled by the actual compiler.
Links
- Crux is a tool for improving the assurance of software using symbolic testing.
- C Intermediate Language (CIL)
Thursday, October 31, 2024
Book
At 17:25, I received the book jurrian van den berg: verzamelaar van dingen written and illustrated by Linda Rusconi in Dutch and published by Lecturis in November 2024, ISBN:9789462265271, from the Lecturis webshop for € 40.00.Sunday, October 27, 2024
ESP32 I²C without interupts
In some bare metal embedded solutions you do not want to make use of interupts, because they potentially could introduce unpredictable behaviour. If you want to do this for the ESP32 it usually means that you cannot the high-level parts of the ESP-IDF because they are based on FreeRTOS that uses interupts. The implementation of the I²C driver makes use of interupts. The interupt handler is the function i2c_master_isr_handler_default in the file i2c_master.c. In this function i2c_ll_get_intr_mask is used to get the information about the interupt being raised and the function i2c_ll_clear_intr_mask is called to clear the bits. Before, in the function s_i2c_transaction_start, the function i2c_ll_enable_intr_mask is called with I2C_LL_MASTER_EVENT_INTR, which enables the interupts for:- The ACK value received by the master is not as expected (I2C_NACK_INT_ENA_M).
- The SCL stays high or low for more than 2I2C_T IM E_OUT_VALUE (default 16) clock cycles during data transfer (I2C_TIME_OUT_INT_ENA_M).
- The detection of a STOP bit, signaling that the transaction is complete (I2C_TRANS_COMPLETE_INT_ENA_M).
- The SDA's output value does not match its input value while the master's SCL is high (I2C_ARBITRATION_LOST_INT_ENA_M), meaning that some other device is generating signals on the bus or there is an electrical interferance.
- The op_code of the master indicates an END command and a END condition is detected (I2C_END_DETECT_INT_ENA_M).
Link
Saturday, October 26, 2024
Chasing The Dot
Conny and I went to Rijksmuseum Twenthe to see the exhibition Chasing The Dot with installations by Philip Vermeulen. We saw the following installations:- Flying, 2024.
- Fanfanfan, 2021-now.
- You are here, 2024.
- Chasing The Dot, 2021-now.
- Ocular Drift, 2022
- Pules, 2021
We also watched a short documentary about Philip Vermeulen and there also was a room with books and some (related) works. The works are:
- Untitled, Jacob Bill, 1967.
- Trames (2×), François Morellet, 1965.
- Reliëf R 74-14, Jan Schoonhoven, 1974.
- Vega-Tuz, Victor Vasarely, 1981.
- Homage to the square, Josef Albers, 1972.
- Thee Psychick Bible, by Genesis P-Orridge
- Sound Art: Sound as a Medium of Art edited by Peter Weibel.
- Splendid Voids: The immersive works of Kurt Hentschläger by Isabelle Meiffert.
- Quantum, de oerknal en God by Maarten van Buuren.
Next we saw the exhibition Gogbot x RMT (also called: The Tec Divide), which I already saw on Friday, September 13. We watched the works in the following order:
- You are Light an Cabbage, Diana Gheorghiu, 2023.
- Calculating Empires: A Genealogogy of Technology and Power, 1500 - 2025, Kate Crawford & Vladan Joler. (Very large and detailed inforgraphic.)
- Retraining Laziness, T(n)C / Tina Kult and Agnes Varnai, in collaboration with Madeline Hall, 2023.
- Forest filled with pines and electronics, Troika, 2022.
- All Watched over by Machines of Loving Grace, Richard Brautigan, 1967.
- Irma Watched over by Machines, Troika, 2019.
- A Boring Dystopia, Matthias Planitzer, 2023.
- 564 Tracs (
Not a love songis usually a love song), Miloš Trakilovió, 2023. - The Materiality of a Natural Disaster, Hilda Hellström, 2012.
- Technosamanic Systems: New Cosmological Models for Survival, Suzanne Treister, 2020 - Now.
- A Bestiary of the Anthropocene, Disnovation.org, 2021.
Friday, October 25, 2024
19.0° Celsius
The temperature at Twenthe Airport has gone up to 19.0° Celsius, which breaks the previous record of 18.9° on this date in 1953.Tuesday, October 22, 2024
Book
At 16:56, I bought the book On Anarchism written by Noam Chomsky in English and published by Penguin UK in 2013, ISBN:9780241969601, from thrift store Rataplan for € 0.50.Verifying and documenting live-bootstrap
My project "Verifying and documenting live-bootstrap" is one the selected proposals eligible to receive a grant from NLnet Foundation in the April 2024 NGI Zero Core call, alongside 48 other exciting new projects. I have decided not to accept this grant, because I have lost interest in the project, having finished most of what I wanted to achieve and gave a presentation about it on September 29. I made an attempt to also run strace for the other supported CPU's, but failed to do so. I have created a page to present the results and give some background and history of the project as a kind of finalization of my investigations of the past years.Monday, October 21, 2024
23,000 days
Today, it is 23,000 days ago that I was born. I decided to celebrate this special day by treat my colleagues on (small) cake. On Tuesday, January 25, 2022, I celebrated that I was 22,000 days old. On Sunday, 18 July 2027, I will be 24,000 days old.Low-level SPI on ESP32-S3
I am reading Chapter 30 of ESP32-S3: Technical Reference Manual to understand how Low-level SPI works when using it in master mode, using 1-bit SPI, 4-line half-duplex mode, and CPU-controlled single transfer (no DMA), normal bit order, writing and/or reading at most 4 bytes (32 bits), only using DOUT and DIN and skipping CMD and ADDRESS (because we are using 1-bit SPI and there is no need to have those). My notes are:- SPI_WR_BIT_ORDER and SPI_RD_BUT_ORDER set to 0 for MSB first (the default).
- SPI_Wx_REG registers for CPU-Controlled Data Transfer (30.5.5).
- SPI_USR_MOSI_HIGHPART and SPI_USR_MISO_HIGHPART set to 0 (the default).
- SPI_DMA_RX_ENA and SPI_DMA_TX_ENA set to 0 (the default).
- SPI_CLK is generated from clk_spi_mst with SPI_CLKCNT_N and SPI_CLKDIV_PRE.
- SPI_SLAVE_MODE set to 0 (the default).
- SPI_USR_CONF set to 0 (the default) for single transfer.
- SPI_USR_COMMAND set to 0 (not the default).
- SPI_USR_COMMAND_BITLEN set to 0 (the default).
- SPI_USR_ADDR and SPI_USR_DUMMY set to 0 (the default).
- SPI_USR_ADDR_BITLEN set to 0. (The default is 23, which stands for 24 bits). (The address is taken from the SPI_USR_ADDR_VALUE register.)
- SPI_USR_DUMMY_CYCLELEN to 0. (The default is 7.)
- SPI_USR_MOSI set to 1 when writing data (for DOUT).
- SPI_USR_MISO set to 1 when reading data (for DIN).
- SPI_USR_DATA_BITLEN set to number of bits to write and/or read. (The default is 0.)
- SPI_CS_HOLD_TIME set to 1 (the default).
- SPI_CS_HOLD set to 1 (the default).
- SPI_CS_SETUP set to 1 (the default).
- Not sure to set SPI_CS_SETUP_TIME to another value than the default 0.
- All SPI_Fx_DUAL/QUAD/OCT set to 0 (the default) for 1-bit SPI.
- SPI_USR set to 1 (to trigger a SPI operation).
- SPI_UPDATE set to 1 (to synchronize SPI registers from APB clock domain into SPI module clock domain).
Section 30.5.8.4 'Half-Duplex Communication (1/2/4/8-bit Mode)' explains how to set the registers for the desired SPI-usage. My notes:
- The CMD state is not mentioned as being optional. But the CMD can be 0 bits long.
- SPI_DOUTDIN set to 0 (the default).
- Set the FSPICLK according to Section 30.7.
- Configure interrupts.
- Set SPI_DMA_AFIFO_RST, SPI_BUF_AFIFO_RST, and SPI_RX_AFIFO_RST to reset these buffers.
- Set SPI_USR to start the transfer.
The file spi_struct.h gives C struct definition for accessing the different parts of the registers. These are used in the file spi_ll.h. The following 'functions' can be of interest:
- spi_ll_master_init.
- spi_ll_master_cal_clock to calculate the clock settings.
- spi_ll_master_set_clock_by_reg to set these clock settings.
- spi_ll_master_set_line_mode to set the 1-bit mode.
- spi_ll_set_command_bitlen to set SPI_USR_COMMAND(_BITLEN).
- spi_ll_set_addr_bitlen to set SPI_USR_ADDR(_BITLEN).
- spi_ll_enable_mosi and spi_ll_enable_miso.
- spi_ll_set_half_duplex to set SPI_DOUTDIN.
- spi_ll_master_set_clock_by_reg to select the CS to be used.
- spi_ll_apply_config to set apply the register configurations.
- spi_ll_write_buffer to set the data to the SPI_Wx_REG registers.
- spi_ll_user_start to set SPI_USR to start the transfer.
- spi_ll_get_running_cmd to check if the command is still running.
Note that the ports of the device that is being used, also need to be set.
Thursday, October 17, 2024
Links
- Finding all convex tangrams
- Van Der Poel 3D Wooden Brain Teaser Puzzle Solution
- 3D-Puzzle Van der Poel
- Willem van der Poel