Notices by blinry (blinry@chaos.social)

In Hamburg, we currently have a "Volksbegehren" (petition for a referendum) for less annoying advertisements in the city, @hhwerbefrei

The proposal is to ban all ads that are larger than DIN A0, backlit, moving, or too many in one place!

We need 80000 signatures to have a citywide referendum. If you live in Hamburg and are older than 16, please support this!

Learn how: https://www.hamburg-werbefrei.de

"Here, take a Lua ruler! It starts with 1!" #mch2022

Put "Bad Apple" on @piko's giant LED cube hanging over the hackcenter at #eh22!

Greetings go out to @revisionparty! Neat medium for the "Wild" compo :P

2. Many things are fine without sweetening them!

Just putting cocoa powder in plant milk makes a perfectly delicious drink!

@piko's "too-delicious" sugar-free apple cake even sparked a long discussion on whether it was allowed :D https://chaos.social/@piko/114093751535823600

We got some 100% dark chocolate, which is some serious business – but I think I'm getting used to it.

I even got chewing gum without sugar or sweeteners (the brand is "Falim"), which just takes like nothing :D Not sure I'd recommend this…

@piko and I just finished 40 days of not eating sugar or sweeteners! Fresh fruit was the only sweet thing that was allowed – seemed unhealthy *not* to eat those.

We searched through the kitchen and put everything that was disallowed into a box. Was surprised by how many food items randomly contain added sugar. Having them out of sight definitely made this easier!

I used to roll my eyes at people who went "sugar-free", but still ate fruit – after all, they contain lots of fructose and glucose! But after trying it, I now think this is a valid thing to do, because *replacing* table sugar with fruit seems strictly more healthy!

Two takeaways from this phase:

1. Sweetening food with fruit works very well! We made coleslaw with cut-up grapes, for example. And in general, if something should taste sweeter, we added some sweet fruit, like banana or apples.

Next, I tried to do some rendering myself! This would give me a lot of control of the result – I could make subway lines more visible, for example!

Unfortunately, this seems to requires the following tower of technologies:

1. Download the raw OSM data.
2. Import it into a Postgres database using osm2pgsql.
3. Compile the "Carto" style using CartoCSS preprocessor (which seems unmaintained 😱).
4. Run the mapnik renderer.

I had trouble fitting all of these pieces together properly, and gave up.

So it might be nice to use the setup of someone who has figured this out after all.

On https://wiki.openstreetmap.org/wiki/OSM_on_Paper, I found a web service that comes really close to what I'd like:

http://printmaps-osm.de

Most importantly, you can set reasonable map scales like 1:10000, which some other tools didn't allow!

It has a maximum paper size, and some glitches when you come close to it, but I generated two overlapping images and stitched them together in GIMP…

I decided to generate a map at a 1:10000 scale (300 dpi), and then print it at twice the resolution, to have as many details as possible (and a small but readable font size).

So here is my intermediate result: A PNG, to be printed at 600 dpi, showing much of Hamburg at a 1:20000 scale (5 cm = 1 km).

It's 650 MB large :P Take some caution trying to view it!

But… it's really fun scrolling around and seeing what I can find already! :3

https://files.blinry.org/hamburg-20000-600dpi.png

I just took this image to the copy shop, to have it printed – when they tried to open it on their Windows computer, it showed an "insufficient memory" error! :'D

I'd like to print a big map of Hamburg in DIN A0 format, based on #openstreetmap data! 🗺️

Does anyone have recommendations for a command-line tool to generate one? Ideally, you could configure it a bit, to include a lot of street names, and the subway network!

Me: "Generate me a map of Hamburg!"

print.get-map.org: "Here you go! 👍"

It's not what I expected, but maybe what I deserved! :P

Trying what different zoom levels and DPIs look like on paper.

OSM's default tiles are only available in rather low resolution – currently leaning towards a http://printmaps-osm.de export at 1:5000 scale, printed at 600 DPI. That'll have text that's tiny but still readable, and preserve *a lot* of details! :D

I wanted to report on the methods I've tried to get a high-resolution #OpenStreetMap of #Hamburg so far:

https://bigmap.osmz.ru is a bulk downloader for the pre-rendered tiles you see on osm.org. It can even give you a Python script to do that, which you can customize.

Pretty neat tool – but the resolution of the "Standard" layer isn't really high enough for printing, or the text would be *super tiny*!

The new "Tracestack Topo" layer on osm.org has a higher resolution, and would look pretty crisp! But around my preferred map scale of ~1:10000, it doesn't show the outlines of buildings, which I really don't like, so it's not an option. :(

You can compare the two styles (and many other styles) here: https://mc.bbbike.org/mc/?lon=9.989164&lat=53.550867&zoom=16&num=2&mt0=mapnik&mt1=tracestrack-topo

They told me yesterday to send them the file via their web upload – not sure what kind of difference that makes? The PC that couldn't open the file seemed more like a "USB stick handling terminal", so I guess they have more powerful computers in the back…

Anyway, they just told me I could fetch the poster in half an hour! \o/

It's here!! ✨ Love it!

I was too curious about whether the CO2 sensor itself would work, and wired it up temporarily.

And it immediately did what it should, which makes me really happy! \o/ It really is a tiny CO2 sensor now! 🐣

(Yes, I breathed on it for testing in this photo! :P)

Yep, my mistake: I didn't number the pins of the chip correctly! SDA and SCL are pins 8 + 7, not 5 and 6! Not sure how I got that wrong, but it teaches me to double-check next time!

Luckily, the fuel gauge is the one component that's a bit optional – just nice to have!

Resoldering it on the board seems difficult, as it's so tiny! How would you approach that? I mean, I could try to cut the wrong traces, and solder teeny tiny wires to the chip? #electronics

Glued and soldered everything together. Now it feels like a real device! I'm super happy! Thanks again to everyone who has helped me to get this far! <3

The CO2 Canary is open hardware, you can find all source files here:

https://github.com/blinry/co2-canary

I'm planning to write detailed instructions on how to order the required parts, so that you can get one yourself!

#electronics