💾 Archived View for rasputin.selfip.net › minilog.gmi captured on 2022-04-29 at 12:19:46. Gemini links have been rewritten to link to archived content
⬅️ Previous capture (2022-01-08)
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A few days ago I got my Orange Pi Zero 2. Really nice piece of hardware
http://www.orangepi.org/Orange%20Pi%20Zero2/
Unfortunately, the manufacturer website is a little bit awkward. It is slow, provides no SSL encryption and the software is (imho) not well maintained, compared e.g. to the Raspberry Pi stuff. More time to invest to overcome some hurdles.
Yeah - today finally it worked!!! My girlfriend and I were able to see a Starlink space train. Very impressive, worth getting up early! Read more:
gemlog/20210330_starlink_train.gmi
Oh, just discovered, my Gemini server was no longer available after March, 16. The reason was, that the server certificate was no longer valid. I created a new one. Now, we are back in the game. Sorry ...
Today again, Starlink launched another batch of stallites. Meanwhile the weather here improved a bit, so there is maybe a chance for me to see the "Starlink train" in the following nights ...
Since December last year I collect orbit data for Earth satellites from Space Track in a database on one of my machines. The last weekend I wrote a script to make some nice plots. I began with the Starlink satellites. This is an example for the Starlink launch in September 2020:
files/2020-062_movmedian-5.png
I plan to write a longer article about this here.
Today was another launch of 60 Starlink satellites:
https://www.rocketlaunch.live/launch/starlink-22
Unfortunately, weather conditions currently here are still unfavorable to watch the new satellites.
Wasn't here for some days ... was busy. Yesterday, my family and I wanted to watch a Starlink space train. Like this:
https://duckduckgo.com/?q=starlink+space+train&t=h_&iax=images&ia=images
Wasn't quite easy, but eventually we spotted a handful of satellites crossing the constellation Ursa Major from West to East. I'm quite sure, they were Starlinks from the L19 launch on February, 15th this year.
My current µC project is a snake game based on a Arduino Nano clone and a 16x16 WS2812 LED matrix. The challenge is, that most LED matrices of this kind - as well as mine - have a particular order of the LEDs. All the LEDs form a long chain. The chain starts in one corner. In the first row, the index of the LEDs increases from left to right. In the following row, the index increases the other direction. And so on. For the snake game, I have to move a dot on the matrix in any of the four directions up, right, down and left. To achieve this, I have to calculate the new index number of the LED to light up from the index number of the current shining LED (representing e.g. the moving head of the snake). This involved some math with modulo, as I wanted the size of the matrix to be adjustable. I also had to care for the boundaries of the matrix. It took me quite a time, but now it works.
I could have just establish a dedicated 2-dimensional array with proper coordinates and then do a resorting, but this would eat up the tiny SRAM of the ATMEGA328p, that has only 2kByte. I could also change to a µC with more SRAM like the Raspberry Pi Pico I received recently, but this would be less fun for me.
The game is still far from being completed. Currently, I can move the snake around. When the snake "eats" the food, it's tail grows. Also, the tail moves correctly behind the head of the snake. The game is controlled via the keyboard (vim style movement commands with the keys h, j, k and l). The following features are still to be implemented:
You can find the source code on Github.
https://github.com/rzbrk/snake
In the past weeks I had problems connecting to my Linux machines from Windows using SSH client PuTTY. The connection was closed, sometimes already immediately after login. Got the error message "Network Error: Software caused connection abort". In PuTTY, I enabled sending null packets every 5 seconds and enabled TCP keepalives. Hoping, this helps ...
https://superuser.com/questions/294824/putty-network-error-software-caused-connection-abort
What I really like about my Gemlog is, that I can post my thoughts so quickly. I just ssh in my server, edit the file, save, exit ... and that's it!
Yesterday, I ordered a handful of the new Raspberry Pi Pico microcontrollers. Looking forward to playing with them. Wonder, when they will arrive. There is currently a lot of trouble getting products shipped between UK and EU through customs after the Brexit. For some of my projects here a little bit more SRAM than the 2k provided by the Mega328-based Nano clones would be nice.
Bought a SSD for my son's older notebook to speed it up a little bit. Got a cheap used one from Amazon. Smartmontools told me, it ran only 32 hours and had 17 power cycles. And testdisk told me, the drive is clean. Good! You don't believe what I could recover from used storage media in the past!
Мне нравится идея написать здесь что-нибудь по-русски. Я должен практиковаться намного чаще! К счастью, Gemini поддерживает UTF-8.
Yeah, my first non-trivial content for this capsule is published! :) It is a description of my Gemini server setup.
Needed to change the output method for my atom feed. Used method atom_file() of the library feedgen, but it resulted in a corrupted xml (at least for my browser amfora). The atom.xml had not linebreaks, all on one line. Then I used the method atom_str(pretty=True) to get a bytes literal which I wrote to a file in binary mode. This way, I got a nicely formatted xml which amfora could understand.
I use the gemini browser amfora. Unfortunately, it cannot search within a page text. :(
Finally added an atom feed for this capsule. The feed is created by a python script using the library feedgen.
python-feedgen feedgenerator documentation
The Linux Magazine issue 243/2021 featured a very nice tool to conviently put multiple ISO files on a USB drive: Ventoy. You can select the ISO to boot from from a Grub boot menu.
Linux Magazin 243/2021 - A tool for distro hoppers
My son: "Argumented reality" :D
((( CC-BY 4.0 Jan Grosser )))
