Notices by blinry (blinry@chaos.social), page 2

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

Placed an order for two testing boards at JLCPCB! Very exciting!

I added a solder jumper that can be cut to disable the LiPo charger, in case people want to power the device from some other source.

And I added through-hole pads for the voltage provided by the battery and for ground, to be able to measure power consumption more easily using a Power Profiler Kit II.

On a whim, I made the PCB yellow! Seemed fitting for a "CO2 Canary", which I guess is the name of the device now! 🐦

Now, I'm very curious to see whether the device will work! If not, I get to practice my hardware debugging skills, I guess…

Big thanks go out to everyone who has helped me up until this point! I learned so much working on this project so far!

@kicad is a lovely piece of software, I enjoyed using it a lot. Especially the "Design Rules Checker" gave me some confidence that I'm doing things correctly.

The PCBs should ship in a couple of days, I'll keep you updated! :)

Less than a week after placing the order, the boards have been manufactured, assembled, shipped, and are now in my hands!! :O

Happy with the look! 🐥 For the "standard" assembly process, they add these little rails on the sides, which you can then break off.

This is the first time I've designed my own PCB! Now I'm really excited to see whether they'll work! :O

#electronics

The ESP shows up as a USB device, and I can flash the firmware on it! That's a good first sign that there's no fundamental problem with it! *relieved*

Good news: The e-ink display refreshes!

Bad news: It doesn't display what I want!

Maybe I just got pins wrong in the code? Gonna check after lunch! :)

I confirmed that, on my old hardware prototype, the display works with the Rust firmware I developed.

On my PCB, on the other hand, with minimal changes (pin changes), it's just snow.

I remember that I also had that problem when I first wired up the prototype, and the problem was a wrong "busy" pin, I think. So I still think it could be wrong pins? But I gotta investigate more.

@revk @twilliability

I *was* using a wrong "busy" pin! When I changed the pins in the firmware, I looked them up in an old version of the datasheet! 🤦 Now it refreshes like it should! Also, I can power it using a LiPo! \o/

Next problem: The battery level indicator chip isn't reacting – when I speak to it using I2C, I get no response. I'll try to double-check the data sheet, to see if I wired it up correctly?

Whoa!! Have you ever seen the flowers of banana plants?! 🍌