A Four-Year-Old Event Badge Makes An Environmental Sensor

By now we’re all used to the requirements imposed by the pandemic, of social distancing and wearing masks indoors. But as [polyfloyd] and the rest of the board at Bitlair hackerspace in Amersfoort in the Netherlands were concerned, there are still risk factors to consider when inside a building.  Without fresh air the concentration of virus-bearing droplets can increase, and the best way they could think of to monitor this was to install a set of CO2 sensors. To run them they didn’t need to buy any new hardware, instead they turned to a set of event badges, from 2017s SHA hacker camp.

This badge sported an ESP32 module with an e-ink screen, and of most interest for this project it still has a supported software platform and comes with a handy expansion connector on the rear. The commonly-available MH-Z19 infra-red CO2 sensor and BME280 humidity sensor fit on a PCB that follows the shape of the badge with a protrusion at the top on which they appear as an integrated unit. Processing those readings is a MicroPython badge app that issues warnings via MQTT and plots a CO2 graph on the screen. Everything is available, both the hardware in a GitHub repository and the software as a badge.team app.

We applaud anyone who makes use of an event badge for a project, and especially so for using one years after the event. The SHA badge and its descendants are uniquely suited to this through their well-supported platform, so if you have one in a drawer we’d urge you to pull it out and give it a try.

Playing The Pixelflut

Every hacker gathering needs as many pixels as its hackers can get their hands on. Get a group together and you’ll be blinded by the amount of light on display. (We propose “a blinkenlights” as the taxonomic name for such a group.) At a large gathering, what better way to show of your elite hacking ability than a “competition” over who can paint an LED canvas the best? Enter Pixelflut, the multiplayer drawing canvas.

Pixelflut has been around since at least 2012, but it came to this author’s attention after editor [Jenny List] noted it in her review of SHA 2017. What was that beguiling display behind the central bar? It turns out it was a display driven by a server running Pixelflut. A Pixelflut server exposes a display which can be drawn on by sending commands over the network in an extremely simple protocol. There are just four ASCII commands supported by every server — essentially get pixel, set pixel, screen size, and help — so implementing either a client or server is a snap, and that’s sort of the point.

While the original implementations appear to be written by [defnull] at the link at the top, in some sense Pixelflut is more of a common protocol than an implementation. In a sense, one “plays” one of a variety of Pixelflut minigames. When there is a display in a shared space the game is who can control the most area by drawing the fastest, either by being clever or by consuming as much bandwidth as possible.

Then there is the game of who can write the fastest more battle-hardened server possible in order to handle all that traffic without collapsing. To give a sense of scale, one installation at 36c3 reported that a truly gargantuan 0.5 petabytes of data were spent at a peak of rate of more than 30 gigabits/second, just painting pixels! That’s bound to bog down all but the most lithe server implementation. (“Flut” is “flood” in German.)

While hacker camps may be on pause for the foreseeable future, writing a performant Pixelflut client or server seems like an excellent way to sharpen one’s skills while we wait for their return. For a video example check out the embed after the break. Have a favorite implementation? Tell us about it in the comments!

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Name A Hacker Camp

Many of us look forward to visiting a summer hacker camp, as an opportunity to immerse ourselves in some of the coolest and most stimulating stuff that comes out of our community. The names trip off the tongue, ToorCamp, CCCamp, EMFcamp, BornHack, and more.

There’s one major event that doesn’t trip off the tongue in the same way though, because though it’s one of the oldest in our calendar it doesn’t have the same name every time. Since the end of the 1980s the Netherlands has seen a sequence of  hacker camps with three letter names such as HAR, OHM, and SHA. Every four years these events delight and amaze us, and every four years they need a new name. Do you think you can help them pick one for 2021?

There are a few ground rules to observe, for the would-be coiner of a new moniker. The tradition is of a three-letter acronym, usually one with a meaning somewhere in technology, and so far always containing the letter H somewhere to stand for “Hack” in some form. The idea is that it should somehow encapsulate the spirit of hacker camp culture rather than simply be three words containing “Hack”. HAR for example was Hacking At Random, OHM was Observe Hack Make, and SHA was Still Hacking Anyway. So if you can dream up a TLA within those parameters, there is a group of hackers in the Netherlands who might like to hear from you. We suspect that HAD is already taken.

If you want to know more about the Netherlands camps, read our review of SHA, in 2017.

Header image: [Renze]. “Met Elkaar Hacken” means something close to “Hack together”.

Behind The Scenes Of A Hacker Conference

If you’ve been to a few hacker camps then you’re aware they are not the products of giant corporate entities but volunteer run community groups. You may even have volunteered yourself, and done all sorts of interesting tasks that go towards the running of the camp. But few of you will have been on the orga team of a camp, the people who put in the hard work of making it happen from start to finish. Julius ter Pelkwijk has, and at the 2018 Electromagnetic Field camp in the UK he gave us an insight into the experience.

Of course, Julius isn’t a member of the EMF orga, instead the camp that gave him the experience was last year’s SHA2017 in the Netherlands. This was over twice the size of EMF 2018, on the Dutch polder at Scoutinglandgoed Zeewolde, a scout camp in a forest next to a dyke, and while from our perspective it was a huge success, it was fascinating to pull back the curtain and hear from the other side of the event.

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That Decentralised Low Voltage Local DC Power Grid, How Did It Do?

Early on in the year, Hackaday published one of its short daily pieces about plans from the people behind altpwr.net for a low voltage DC power grid slated for the summer’s SHACamp 2017 hacker camp in the Netherlands. At the time when it was being written in the chill of a Northern Hemisphere January the event seemed so far away, but as the summer fades away along with the deep tan many SHACamp attendees gained in the Dutch sunlight it’s worth going back and revisiting the project. Did they manage it, and how did they do? This isn’t really part of our coverage of SHACamp itself, merely an incidental story that happens to have the hacker camp as its theatre.  Continue reading “That Decentralised Low Voltage Local DC Power Grid, How Did It Do?”

Ourselves As Others See Us Through The Lens Of Traditional Media

When I presented myself at the SHACamp 2017 info desk bright and early on the first full day of the camp, I was surprised to find that I was to be assigned a volunteer along with my press badge. Because of the way our community is sometimes covered by the traditional media, it was necessary that any journalists touring the site have a helping hand to ensure that they respect the privacy of the attendees, gain permission from people likely to be in any photographs, and generally not be idiots about the whole Hacker thing. I pointed out that I was working for Hackaday and not The Sun, and that as an active hackspace member and former hackspace director I was very much a part of the community attending SHA 2017 who would simply be wasting the valuable time of any volunteer assigned to me. Fortunately for the next volunteer in line they agreed with my point of view, so one of the angels was spared a day of my breakneck walking pace and impenetrable British colloquialisms.

It’s interesting therefore a few weeks after the event, to investigate how it was portrayed through the eyes of people who aren’t coming as Hackaday is, from within the bubble. To take a look at that disconnect between what we know about our community and its events, and how the traditional media sometimes like to portray us. Are they imagining the set of a Hollywood “hacker” movie in which assorted geniuses penetrate the computer systems of various international institutions by the simple expedient of banging wildly at a keyboard for a few seconds, or will the reality of a bunch of like-minded technology enthusiasts gathering in a field for several days of tinkering and other fun activities be what makes their reports?

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SHACamp 2017, A Personal Review

There are a series of stages to coming down from a festival. After the hectic rush of travel there are the several days of catching up on lost sleep and picking up the threads of your life again, then once a semblance of order has been regained there’s that few weeks of emptiness. Your life will never be the same again, it’s all so mundane.

I'm pleased to say the Hackaday and Tindie stickers were very popular.
I’m pleased to say the Hackaday and Tindie stickers were very popular.

It’s now a couple of weeks since the SHACamp 2017 hacker festival in the Netherlands was in full swing, and the write-up below has slowly taken shape over that time amid the other work of being a Hackaday scribe and editor. It’s early morning here in Southern England as I write this, so on the equivalent day while I was at SHACamp at this time I would have been carrying a large pack of stickers for distribution on the swapping table through the rising sunlight of a camp still largely asleep after the previous night’s revelry. Past our German and Dutch immediate neighbours, down the ramp from the dyke, the cardboard tent depot on my left and the food court on my right, to the information tent. Greet the bleary-eyed volunteer at the end of their graveyard shift, and spread plenty of Hackaday and Tindie stickers on the table for the masses. And then? Find a coffee, and sally forth into the field for another day among one of the most stimulating communities on Earth. My community. Your community.

The sticker table is a good place to start if you wish to get a handle on a large hacker camp. On it you will find the logos of a cross-section of the diverse organisations and groups present. There are a few commercial ones like my Jolly Wrenchers and Tindie the puppy, there are some from voluntary organisations or interest groups, but mostly they are the logos of a continent’s — even the wider world’s in some cases —  hackspaces and makerspaces. Here you see the breadth of the attendees, as the logos of spaces from thousands of miles away you’ve never encountered before mingle. This isn’t quite a global gathering, but there is a sense of global community around it.

How Do You Describe a Hacker Camp?

You shall find us by our clearly superior yet dangerous to barefoot pedestrians fused right-angled mains connector.
You shall find us by our clearly superior yet dangerous to barefoot pedestrians fused right-angled mains connector.

So before I take you through my experience of SHA, it’s best to start by describing a hacker camp in more general terms. When I’m describing a camp like SHA to the kind of people who don’t read Hackaday, I put it as similar to the music festivals they are used to but without the bands. Instead the audience provides the entertainment through the work they bring to the event or do at the event, and through a comprehensive program of talks and lectures. Oh — and this is the bit that makes their eyes open wide — every structure on site from the smallest one-man tent to the largest marquee has mains power and high-speed Internet. Sometimes people grasp what SHA is from this description, sometimes they don’t.

Different groups, be they individual hackspaces, people from a particular country, or other special interest groups, congregate in villages, collections of tents, marquees, and gazebos in which they set up whatever cool stuff they’ve brought along. My tent with its Hackaday flag was in a village composed of a mix of British hackspaces up on the dyke, which [Michael] from MK Makerspace had marked with a sign consisting of a huge BS1363A mains plug. More than one person pointed out it would have been better lying flat on the ground with pins in the air, ready to catch an unwary Monty Python foot.

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