Giant Pacific Octopus - <AUTHOR> https://www.nationalgeographic.com/animals/invertebrates/g/giant-pacific-octopus/ <comment><USER2> When I was a kid, my father used to raise octopi in our basement in NYC as a hobby. He had about six 55-gallon tanks arranged in two rows.

Every day, he'd come home from work, throw his hat and tie on the coatrack, and immediately head to the basement to play with them. If you didn't play with them, they'd die of boredom, he said.

Their favorite game was "jar." He's put empty Gerber and Ball jars in the tanks, with lids, and they'd swim in and out and in and out of the open jars. Eventually, they'd learn to open the closed jars. And then they'd spend hours swimming inside the jars, and closing the lids behind them, and trying different sized lids to see which ones worked on which jars. It was all very fulfilling to my father.

I don't know what happened to the octopi when they got mature. My guess is that he sold them to pet stores or restaurants or something.

<comment><USER3> unfortunately and to shatter your dreams, as mine were, it is and has always been:

octopuses*

tis mixage of greik and latin eytymologies and wyll not bey allowed

by the way is your dad thomas pynchon?

<comment><USER4> "The Oxford English Dictionary lists octopi, octopuses and octopodes (in that order)"

[https://en.wikipedia.org/wiki/Plural_form_of_words_ending_in...](https://en.wikipedia.org/wiki/Plural_form_of_words_ending_in_- us)

<comment><USER5> Does it?

octopus

(ˈɒktəpəs, ɒkˈtəʊpəs)Pl. octopodes (ɒkˈtəʊpədiːz), anglicized octopuses.[mod.L. octōpus, a. Gr. ὀκτώπους, acc. ὀκτώποδ-α eight-footed, f. ὀκτώ eight + πούς, πόδ- foot.]

octopus

A genus of cephalopod molluscs, characterized by eight `arms' surrounding the mouth and provided with suckers; an individual of this genus (esp. one of the larger and more formidable species).

1758: Baker in Phil. Trans. L. 778 "The Polypus, particularly so called, the Octopus, Preke, or Pour-contrel."

1835: Kirby Hab. & Inst. Anim. I. x. 308 "The body of the octopus is small, it has legs sometimes a foot and a half in length, with about two hundred and forty suckers on each leg."

1880: Browning Pietro of Abano 401 "Help! The old magician clings like an octopus!"

1884: H. M. Leathes Rough Notes Nat. Hist. 46 "Saying that enormous octopuses existed on the western side of Panama, in the Pacific Ocean."

octopus

b. fig.; usually applied to an organized power having extended ramifications and far-reaching influence, esp. harmful or destructive.

1882: Greg Misc. Ess. ii. 37 "We are the very octopus of nations."

1893: Boston (Mass.) Jrnl. 25 Mar. 2/1 "The electric octopus. Formal organization of the New England Street Railway Company."

1894: Westm. Gaz. 12 Mar. 2/1 "He was an administrative octopus, a cormorant of toil."

octopus

c. attrib. and Comb.

1880: G. Meredith Tragic Com. (1881) 206 "Then they laid octopus-limbs on her."

1894: Outing (U.S.) XXIV. 460/1 "An octopus power sought to tear the human limpet from its clinging place."

1898: P. Manson Trop. Diseases i. 9 "A strange-looking octopus-like creature."

</comment></comment></comment></comment><comment><USER6> If you find the topic of non-human intelligence, esp. octopus intelligence interesting, you may find Adrian Tchaikovsky's children of Ruin series worth your time. The 2nd book, without ruining too much of the story, has octopii as one of the central characters. [1]

Going out further afield, exploring forms of intelligence & cognition that are very different from humans, Peter Watt's blindsight (firefall) series is an idea-filled, dense, very satisfying read. [2]

[1][https://www.goodreads.com/book/show/40376072-children-of- rui...](https://www.goodreads.com/book/show/40376072-children-of-ruin)

[2] [https://www.goodreads.com/book/show/48484.Blindsight](https://www.goodreads.com/book/show/48484.Blindsight)

<comment><USER7> I'd really like to hear the feedback from those in AI-complete or cognitive science research about Blindsight and especially Watts' notes [1], and if we could implement "merely" sentient AI with no consciousness, or if sentience backed by human-capacity reasoning and learning somehow lead to sapience. Because Watts makes an effective argument with his copious bibliography that "only" sentience can Accomplish A Hell Of A Lot.

Could a "merely" sentient software-driven but not conscious/self-aware robot be built that washes my dishes / cutlery and puts them away, keeps my permaculture garden tended/weeded, separates recyclables, washes, hang dries when feasible / conventional-dries when not, folds, puts away clothes / towels / fabric products, dusts, vacuums, puts away clutter, _etc._?

[1] [https://www.rifters.com/real/Blindsight.htm#Notes](https://www.rifters.com/real/Blindsight.htm#Notes)

<comment><USER8> IANACognititive scientist, but:

Yes, I don't think anyone in AI research believes human-style self-awareness is needed for those tasks. Well, putting away clutter might be tricky, just in getting human definitions of "put away". Most of the rest of them are just high-level pattern matching.

I think consciousness is worthwhile for communicating useful thought patterns to your peers. This is consistent with the modern perspective that "consciousness is just stories you tell yourself" and even the Watts perspective that it's inefficient. Those stories about yourself are in fact useful if they make your tribemates more effective, and (as anyone knows who has thought about communication overhead in a large organization) the individual inefficiency is offset by the power to harness a hundred or a million individuals to the same task.

</comment></comment></comment><comment><USER9> The short life span always interested me, especially being high intelligence. It lives long enough to breed, serving it's short singular purpose.

I'd love to see a comparison of the life spans of various animals/species. It would make for a good graphic/visualization. I'm guessing this sort of lifespan is more common than not, compared to say whales living ~50yrs.

Edit: I found two good infographicy examples, although Id love something far more in depth

[https://payload.cargocollective.com/1/13/443926/6626429/ANIM...](https://payload.cargocollective.com/1/13/443926/6626429/ANIMALS_o.jpg)

[https://www.alansfactoryoutlet.com/how-long-animals-live- the...](https://www.alansfactoryoutlet.com/how-long-animals-live-the-life- spans-of-50-animals)

<comment><USER10> Given their intelligence, one wonders what they would be like if they lived say 20 years? Would they be ruling the oceans?

<comment><USER11> I find this amusing as this is an inherently human emotional evaluation. Perhaps that is not the point in the grand scheme of things?

Octopuses have survived for 500+ millions of years and I would say more intelligent and peaceful than humans who 'ruled' or savaged their own species for... what benefit actually?

<comment><USER12> A viable chance at getting off this rock.

500+ million years is a blink of an eye on a cosmic scale. Humans are the only species we've observed that has a viable chance or surviving on cosmic time scales; and we will likely bring other life along with us for that ride.

Short of another human-equivalent species evolving, or a hyper resilient organism that can piggy back on space debris, humans are literally the only shot life on Earth has.

<comment><USER11> Why does that matter? Why are humans so special? I 'feel' like octopuses are the better candidate :) putting aside trivial human aspirations....

<comment><USER12> When they successfully escape earths orbit, get back to me.

Until then, all odds are stacked against them. They're going to go extinct in an instant on a cosmic timescale. Unless, of course, humans choose to bring them along and save them from that fate.

<comment><USER13> I'm not necessarily disagreeing, but it's interesting to me that in our many hundred thousand year history as a species, the "point" of our intelligence (by your measure) wasn't even a suggestion until maybe 120 years ago, and only a dream until maybe 60 years ago. What are the chances?

Perhaps a scholar in 320 AD would also have been surprised by how remarkable it was that the true purpose of human intelligence had only been so recently discovered.

<comment><USER12> Bingo.

This is the chasm that needs to be crossed. Its not just the immediate advantage your species gets from intelligence. It's cultivating that to a point where you realize all life on this planet is default extinct. Then getting your species to the point where you even have a _chance_ of changing that default.

Humans are still default extinct. We are on a path to changing that default.

<comment><USER14> No we're not, at best we're just changing the timeline. You're still either time bound by the death of the universe best case scenario or resource bound before that happens (if the universe can "end"). Extinction is inevitable at any timescale.

<comment><USER15> Well the whole point of the game of life is to keep the game going for as long as possible.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER16> I just finished watching a Netflix documentary about an octopus. The kids loved it.

It was probably one of the most fascinating documentaries I have ever seen. What a story & some amazing footage. I could not help but think that octopus are very intelligent.

"My Octopus Teacher"

Edit: spoiler alert on the link. Watch it without reading Wikipedia. The twists and turns are part of the experience.

[https://en.m.wikipedia.org/wiki/My_Octopus_Teacher](https://en.m.wikipedia.org/wiki/My_Octopus_Teacher)

<comment> noman-land +1 for this documentary. Really interesting relationship and some incredible footage.

</comment></comment><comment><USER17> I highly recommend the book "Other Minds", a fascinating and very accessible book about the octupus and cuttlefish. They are amazing creatures.

[https://www.amazon.com/Other-Minds-Octopus-Origins- Conscious...](https://www.amazon.com/Other-Minds-Octopus-Origins- Consciousness/dp/0374227764)

<comment><USER18> Great book.

</comment></comment><comment><USER19> I love octopus. They are one of my top favourite life forms.

Did you know that we are discovering they are a bit more social than we thought?

[https://www.smithsonianmag.com/smart-news/octopus-city- obser...](https://www.smithsonianmag.com/smart-news/octopus-city- observed-180964936/)

How about these sleepy heads, eh?

[https://www.youtube.com/watch?v=RHR70lVy79Y](https://www.youtube.com/watch?v=RHR70lVy79Y)

One wonders just what sort of other crazy hijinx they get up to, personally .. I once watched a reef occy lure some dumb fish into his lair with an old crayfish carcass, it amused me for hours watching him/her lazy fishing from a hole ..

If you ever find yourself in occy territory, i.e. on a tidal Rockpool, and you suspect there might be one in a hole somewhere, flash some coins and direct sunlight into the depths .. I often find they can't resist the opportunity to add some shiny to their middens ..

</comment><comment><USER20> Highly recommend the documentary My Octopus Teacher on Netflix. Beautiful story of how a free diver forms a friendship of sorts with an octopus.

Preview here: [https://www.youtube.com/watch?v=3s0LTDhqe5A](https://www.youtube.com/watch?v=3s0LTDhqe5A)

<comment><USER21> I also highly recommend My octopus teacher.

Very beautiful and sad in a "circle of life" kind of way.

</comment></comment><comment><USER22> Related: Giant Pacific Tree Octopus [https://zapatopi.net/treeoctopus/](https://zapatopi.net/treeoctopus/)

(one of the classics of the early internet)

<comment><USER23> This was our introduction to "not everything on the internet is true, even if it's presented nicely" circa middle school. Glad to see it's still up and running!

</comment></comment><comment><USER24> Hearing about the Giant Pacific Octopus always reminds me of the story about the guy who found a novel way to go Octopus hunting when hunting them was illegal.

[https://www.nytimes.com/2013/10/20/magazine/the-octopus- that...](https://www.nytimes.com/2013/10/20/magazine/the-octopus-that-almost- ate-seattle.html)

<comment><USER25> I still don't get why the article elevated what was essentially an illegal hunt by a teen idiot.

Nothing novel about it. Just breaking rules and conventions to kill a creature for food.

<comment><USER26> I think we read a different article. It made it clear it was a legal hunt by a teen who did some homework on it.

<comment><USER25> Did you read the comments? The locals knew that octopus. The octopus was an attraction for nearby divers.

He killed it and doomed its babies.

The article was written by someone clearly amoral about the whole issue.

<comment><USER27> That added context makes it sad, but does not make it illegal, which is what you are responding to.

</comment></comment></comment></comment></comment><comment><USER11> Octopuses are so fascinating. We scour other planets and galaxies for life / mystical aliens sending aimless signals in search of reciprocation or even acknowledgement.

I wonder how amazing it would be if we had a similar grand undertaking in our oceans... With just octopuses (without interfering with them)?

They are perfect aliens we are seemingly looking for in the skies but living right alongside us....

</comment><comment><USER28> A new documentary on Netflix called, "My Octopus Teacher" is worth checking out.

"An unusual friendship develops between a filmmaker and an octopus living in a South African kelp forest that shares the mysteries of its world."

[https://www.netflix.com/watch/81045007](https://www.netflix.com/watch/81045007)

</comment><comment><USER29> I highly recommend a documentary on Netflix named, "My Octopus Teacher". It's really beautifully made. A man becomes "friends" with an octopus and goes to meet and observe every day for a year until she mates and dies. It's amazing.

</comment><comment><USER30> Until clicking I didn't know if this was going to be a software product or an animal ;)

</comment><comment><USER31> Does their brain consciously drive the control of their cell pigment/color ability, or is it something more subconscious/reactive/instinctive? Seems like the brain has to be involved to coordinate...

I wonder what the closest thing like that would be for humans? Would it be akin to me _thinking_ "i want to be more tan" and somehow my cells get the signal to be more tan?

Obviously we will likely never know, but there is some leap here I wish we understood better. (Or do we and I'm just unaware?)

Edit: thinking about it more... i don't know what happens when i think to "make a fist" and yet it happens, so maybe it is something more at that level...

<comment><USER32> I think more like moving your body. You can do it when you want to, you can do it on autopilot with varying degrees and axes of control, or do it while asleep. You don't need to subvocalize it, you think more about the result, next intentions, etc.

<comment><USER31> Thanks! That does make sense, and it's entirely fascinating to think about!

Does anyone know what this area of study is called?

<comment><USER33> Look into cognition vs consciousness.

A baby can feed themselves holding a spoon, but they lack object permanence (the ball went behind the couch, it's vanished from this universe forever), and certainly aren't aware of stuff like their own mortality, their favorite color, or if they even should have a favorite color, etc

Child development is a lot more studied than I thought it was, and opens a lot of doors to exploring the answers to some of these questions.

</comment></comment></comment></comment><comment><USER34> I'm not sure if it's still alive, but if you're in Toronto, Ripley's Aquarium has one. Though, it's kept in the 'Canadian Waters' gallery for...reasons.

"Ripley's Aquarium of Canada is home to a giant Pacific octopus (Enteroctopus dofleini). This species of octopus is the largest of 300+ known octopus species. There is a huge variation in size that depends on the individual, but the average for this species is considered around 15-18kg (33-40lb), with an arm span around 4m(12-14ft) when stretched out. Of course, we can't talk about size without mentioning the world record – OVER 130kg (300lb) and 9m (30ft) wide! There has also been the occasional "fisherman's tale" of even larger individuals, but the proof isn't quite there yet.

The giant Pacific octopus can live to be about four years old, with both males and females dying soon after breeding. Females live long enough to tend to their eggs, but they do not eat during this months-long brooding period, and usually die soon afterwards."

[https://www.ripleyaquariums.com/canada/tag/qa/](https://www.ripleyaquariums.com/canada/tag/qa/)

</comment><comment><USER35> > The size record is held by a specimen that was 30 feet across and weighed > more than 600 pounds

What?!? That's incredible! It would be so incredibly terrifying to see one of those in its natural habitat.

I tried searching for more information about the largest one found, but I didn't find much. The only information I could find was that it was found on a beach in British Columbia. I was really hoping for a picture of it.

</comment><comment><USER36> There's a nice little Ted talk by David Gallo about life in the ocean. Most of it is about what cephalopods can do. It's really amazing: [https://www.ted.com/talks/david_gallo_underwater_astonishmen...](https://www.ted.com/talks/david_gallo_underwater_astonishments)

</comment><comment><USER37> My first concept of octopi as a highly intelligent species came from this essay: [https://orionmagazine.org/article/deep- intellect/](https://orionmagazine.org/article/deep-intellect/) Highly recommend it to anyone who likes these creatures.

</comment><comment><USER38> If you're interested in human octopus interactions I recommend Sy Montgomery's Soul Of An Octopus.

[http://symontgomery.com/soul-of-an-octopus/](http://symontgomery.com/soul-of- an-octopus/)

</comment><comment><USER39> The sheer alien-ness of cephalopod intelligence reminds me of the current conversation about AI and whether they are "truly" thinking or just mechanistic. It's easier to see an octopus as executing a highly advanced algorithm than it is to see ourselves that way. And we can look at them and appreciate their sophistication yet have no way of understanding their internal experience.

</comment><comment><USER40> If you like octopusses I highly recommend the EV Nautilus channel on youtube: [https://www.youtube.com/watch?v=lbHjs9A7sis](https://www.youtube.com/watch?v=lbHjs9A7sis)

They livestream ocean exploration with remote controlled submarine, it produces wonderful footage.

</comment><comment><USER41> On the subject of octopuses, Radiolab did a neat "octomom" episode that's worth a listen.

[https://www.wnycstudios.org/podcasts/radiolab/articles/octom...](https://www.wnycstudios.org/podcasts/radiolab/articles/octomom)

</comment><comment><USER42> FTA:

> They live to be about four years old, with both males and females dying soon > after breeding.

> Highly intelligent creatures, giant Pacific octopuses have learned to open > jars, mimic other octopuses, and solve mazes in lab tests.

What would be the point of evolving to be so intelligent if the lifespan is so short. Seems strange to me.

<comment><USER43> Speedrunning the wheel of reincarnation?

Bonus multifilm: [https://www.youtube.com/watch?v=YkdhJWyzFR8&t=37](https://www.youtube.com/watch?v=YkdhJWyzFR8&t=37)

</comment></comment><comment><USER44> Reminds me of octopus wrestling in the PNW back in the 60's.

[https://en.wikipedia.org/wiki/Octopus_wrestling](https://en.wikipedia.org/wiki/Octopus_wrestling)

</comment><comment><USER45> The coolest creatures. I love them!

</comment><comment><USER46> They only live for 4 years?

</comment><comment><USER47> I wonder why people keep ignoring standards and use feets, pounds etc even on quite international resources. I understand it is convenient on local market to buy some food, but in this kind of scientific articles makes no sense to me.

<comment><USER48> _> even on quite international resources._

By that, are you referring to _National_ Geographic? :)</comment></comment>


Ask HN: Are micro-freelance code jobs possible? - <AUTHOR>

I am a newbie founder learning to code and creating a web app to practice. Sometimes I am completeley stuck and no amount of Google and Stackoverflow solves my problem. What I really want is to some senior developer remotely access my code and (eg) correct the bug of how my app relate to my database now that it is published on Azure.
Something that I already spent 3 days trying to do it and I am sure a developer with experience on it would solve in no more than an hour.
I don't want to outsource my code, or hire a freelancer for a job worth $10,000. I just want one or two hours of his/hers time to fix a very specific bug. A marketplace like this would be very valuable for me. What do you think? <comment><USER2> See <http://tweaky.com>. It doesn't look like they do the kind of coding tasks you're talking about (yet). But I agree there's a need for a marketplace like that.

<comment><AUTHOR> Great! Thanks revorad, that's it! Actually not for the problem I used as example, as their focus is more about front-end and some tools integration, and not much worried about developers having problems with more complex code.

But that will be a good resource to me! I'll check if they can quote a more complex problem there.

</comment></comment><comment><USER3> Check out fiverr.com.

I think the problem is that it's sometimes difficult to read someone else's code. What happens if it takes 2 hours just to read your code..or if it requires a complete rewrite to fix it properly? Would you be willing to pay for 8 hours of work to get your issued fixed?

For me, it just wouldn't be worth it.

<comment><AUTHOR> $5? If I can't solve it with Google, it is worthy more than $5! :) I am thinking about rates between $30 and $150 per hour.

I think must be a protocol to understand the size of the problem. If it is something that will need more than, say, 10 hours, so it becomes a traditional freelance job.

But this risk you say happens on every freelance or outsource job of any size. A freelancer that expects to built a site in 2 weeks, can take 2 months if he didn't do his due dilligence right. A software factory that quote to do a system in 3 months, may take 1 year if the communication on the quote phase was problematic. This happens everywhere, it doesn't justify a "not worthy model" for me.

<comment><USER4> Senior level dev for $150 per hour? Maybe, depending on the niche. $30? I can't imagine someone of that caliber would be interested.

In my area the going rate is well above that, and that isn't for bug fixing.

</comment></comment></comment><comment><USER5> I would post on elance.com I've had projects as little as $25.</comment>


Communicating Sequential Processes - <AUTHOR> http://swannodette.github.io/2013/07/12/communicating-sequential-processes/ <comment><USER3> This looks nice. Less readable than Go (is there GoScript yet?), but still fairly straightforward.

One remark I'd like to make is that I don't see this as having a big advantage over FRP.

The examples with mouse coordinates look like an imperative approach to FRP. With the latter, one wouldn't have to explicitly set up a channel and read from it -- that is an implementation detail in FRP.

To emphasize the contrast, I'd call this channel-based approach an Imperative Communicating Programming (ICP). Your code does not react to changes like it does with FRP. Instead, you as a programmer ask for changes, very often in an infinite loop, and then transform those changes into a side-effect in the browser.

On one hand, channels + goroutines provide a single abstraction with which it is kind of straightforward to implement various concurrently executing threads of code. On the other hand, those infinite loops and their proliferation in the channel-based code will definitely cause some people to cringe and go with FRP instead.

I don't think FRP is as applicable as channels to as many use cases. Channels are more low level and therefore more potent. But for what FRP does, it provides a better (read "more concise", or "declarative") abstraction for it.

<comment><AUTHOR> Note that in some ways core.async is a bit more flexible than Go - for example you can dynamically select over a changing list of channels. I've found this to be really handy especially when you're receiving channels on channels.

you can do everything in an FRP style if you like with core.async, it's flexible enough for that. But I think for less toy examples this is undesirable as you allude.

<comment><USER4> > Note that in some ways core.async is a bit more flexible than Go - <USER2> > example you can dynamically select over a changing list of channels

[http://golang.org/pkg/reflect/#Select](http://golang.org/pkg/reflect/#Select)

<comment><AUTHOR> You should look a bit more closely at what I said :)

EDIT: Oops, I didn't see you had linked to the _reflect_ features. I did not know that and that is very cool.

<comment><USER4> You said: "for example you can dynamically select over a changing list of channels"

reflect.Select does exactly that.

</comment></comment></comment></comment></comment><comment><USER5> Cool stuff! A couple of days ago I listened to Rich Hickey talk more about core.async on the most recent ThinkRelevance podcast:

[http://thinkrelevance.com/blog/2013/07/10/rich-hickey-and- co...](http://thinkrelevance.com/blog/2013/07/10/rich-hickey-and-core-async- podcast-episode-035)

I've written a few client side projects in ClojureScript, and I haven't been totally happy with the way I end up doing event handling. I'm excited to give this a try.

By the way, I love that this is the sort of thing you can do with just a _library_ in Clojure.

<comment><USER6> Brilliant!!. Can someone point me to an open source project which uses core.async so I can see it in action.

<comment><USER7> This is an example of Peter Norvig's spellchecker written with core.async by Stuart Sierra (@stuartsierra): [https://gist.github.com/stuartsierra/5954022](https://gist.github.com/stuartsierra/5954022)

This is an example of Rock Paper Scissors by Alex Miller (@puredanger): [http://tech.puredanger.com/2013/07/10/rps-core- async/](http://tech.puredanger.com/2013/07/10/rps-core-async/)

</comment></comment></comment><comment><USER8> Brilliant! I had always hoped CoffeeScript or somehow a JS library would add blocking channels like this. Writing JavaScript is a pain after being spoilt by Go.

I'm quite curious about what the compiled code looks like. (On a mobile now, I'll have a look when I can.)

<comment><USER9> It seems like the compiled js code from the page's examples is quite large: csp.js minified ~83kb

I wonder if most of that is the runtime and libraries or the resulting JavaScript code is just that big.

<comment><AUTHOR> There is no runtime and note that's 22k gzipped. This is far smaller than jQuery + Underscore.js + persistent data structure library + stream implementation + async control flow library gzipped which is what you're getting. _jQuery alone is 33k gzipped_.

</comment></comment></comment><comment><USER3> One thing that is not covered in the post is how should we clean up those goroutines that are blocked on channels. I'm not familiar with internal workings of core.async, so I'm looking at it from Go's point of view.

Imagine that in the search example, inside the `google` function, we want to read from 100 channels. And each call to `fastest` is supplied with 100 arguments. If on average we get 100 results back in the allotted time, 900 goroutines will be left in a blocked state waiting for someone to read from their respective channel.

I'm guessing those goroutines are cheap and are implemented as some sort of state machine that maps to callbacks. But all those blocked goroutines should still incur runtime cost. Will the GC kick in collect those?

If this issue is really there (i.e. if I'm not mistaken), imagine what will become of your one-page-web-app after you click on that Search button a dozen of times.

<comment><AUTHOR> go blocks are cheap to construct and yes they will be GCed. You can trivially debounce the click channel.

<comment><USER3> Thanks for the info! I'm willing to get my hands dirty and see how it's all implemented there.

Just for the record, in Go, if you leave a goroutine blocked on a channel, the channel and the goroutine will remain on the heap unless you read everything from the channel (normal way) or close it (and get a runtime panic).

</comment></comment></comment><comment><USER10> Can some of the clojure and clojurescript gurus take some time to write beginner friendly, hand holding tutorials? I mean, I can see the power of these technologies but the very thought of climbing a learning curve AS WELL AS a getting started curve ( that too without any external help! ) is the single most important thing that turns people off.. especially me. My general complaint is with regard to how many tutorials and even books are out there on these topics! Countable, with the fingers in one hand perhaps!

<comment><USER11> Discoverability is a problem, but the Clojurewerkz people are top-notch ([http://clojurewerkz.org/](http://clojurewerkz.org/)). These are helpful:

* Intro: [http://clojure-doc.org/](http://clojure-doc.org/)

* Libs: [http://www.clojure-toolbox.com/](http://www.clojure-toolbox.com/)

* Examples: [http://clojuredocs.org/quickref/Clojure%20Core](http://clojuredocs.org/quickref/Clojure%20Core)

* Pedestal: [https://github.com/pedestal/app-tutorial](https://github.com/pedestal/app-tutorial)

Also a few books at different levels:

* [http://www.clojurebook.com/](http://www.clojurebook.com/)

* [https://leanpub.com/fp-oo](https://leanpub.com/fp-oo)

* (2nd ed early access available) [http://joyofclojure.com/](http://joyofclojure.com/)

* [http://pragprog.com/book/shcloj2/programming-clojure](http://pragprog.com/book/shcloj2/programming-clojure)

* [http://www.manning.com/rathore2/](http://www.manning.com/rathore2/)

* [http://www.packtpub.com/clojure-data-analysis-cookbook/book](http://www.packtpub.com/clojure-data-analysis-cookbook/book)

<comment><USER12> I would also mention following tutorial on CLJS: [https://github.com/magomimmo/modern- cljs](https://github.com/magomimmo/modern-cljs)

</comment></comment></comment><comment><USER4> "languages like CoffeeScript, Dart, and TypeScript. These languages fail to address the single largest source of incidental complexity for any sizeable client side application - concurrency."

Dart fails to address concurrency? I don't think so: [http://www.dartlang.org/docs/dart-up-and- running/contents/ch...](http://www.dartlang.org/docs/dart-up-and- running/contents/ch03.html#ch03-dartisolate---concurrency-with-isolates)

<comment><AUTHOR> I'm not sure you actually read the post, isolates do not address the same issues at all - you can't share data between isolates and you can't put isolates onto isolates limiting coordination possibilities - all of these are possible with channels.

<comment><USER4> You can at least send a SendPort over a SendPort:

"Isolates send messages using SendPorts, and receive them using ReceivePorts. The content of a message can be any of the following:

* (...)

* An instance of SendPort"

You can prefer one or the other model, but saying that Dart fails to address concurrency is just not true.

<comment><AUTHOR> I think you're taking my use of the word out of context of the whole post. I'm talking about the concurrency that is imposed by the very nature of client side programming - you have no choice. Isolates don't allow to you coordinate the concurrency that is _already present_.

</comment></comment></comment></comment><comment><USER13> Does anyone have any idea why the mouse-over examples are a more CPU intensive task for Firefox? On my laptop, moving the mouse a lot results in 15% CPU usage, and if I jitter it fast enough it maxes out at 22%. That won't lock up the browser if I'm not doing anything else but still feels like it will drain the laptop battery notably faster with intensive use, if you catch my drift.

With Chrome I can't get it above 4%. IE 10 is somewhere in the middle with 10% (and also has a bug when resizing the window, giving Y values like 2236.65990234375, with the fraction part being constant).

EDIT: Both Opera 12 and Opera 15: 6 to 8%

Also, the second/third examples seem a bit laggy with all browsers: if I shake the mouse quickly the numbers keep updating for a while after I stop. I guess that this is because instead of showing the most recent value it shows all the location values, but the screen updates are slower than the mouse updates?

Either way, when the mouse stops moving while the numbers still update, Firefox only takes 6% of the CPU. Not sure if that clarifies anything, but it might help identify the cause.

<comment><AUTHOR> I don't think you can come to any conclusions from these numbers. I see the exact same CPU utilization across browsers if I replicate the styles and write this JavaScript instead:

       var loc = document.getElementById("location");

       window.addEventListener("mousemove", function(e) {
         loc.innerHTML = e.pageX + ", " + e.pageY;
       });

Which is saying something, the ClojureScript is doing a lot more work and it ain't slow ;)

I suspect all the cost is from repainting large areas at the speed of mouse movement. But the mouse examples are for illustration - in production code you'll probably want to throttle (which would avoid piling up the repaints you observed on slower machines) as well as address the IE 10 edge case.

<comment><USER13> Well, my question was why one browser was slower than the other - I didn't expect ClojureScript to be the cause of the problem. I was just curious about what might cause the difference.

> I suspect all the cost is from repainting large areas at the speed of mouse > movement.

I'm not really a web dev, but isn't this a reflow, not a repaint? Could that be the reason for the difference in performance too? What happens if you use canvas instead of changing a div?

BTW, I forgot to mention this in the previous comment, but: this is pretty cool! I echo the "being spoilt by Go" sentiments of others, so I'm happy to see this library.

</comment></comment></comment><comment><USER14> Maybe it is just me, but I prefer logically to think of actors (or processes) as concurrency primitives not channels, kind of like what Erlang has. For example in go the primary question is "what channel to I write or read from?", in Erlang it is "what is the pid of the process, so I can send it a message?".

<comment><USER15> Channels are a neat generalization of what Erlang has. Btw the first example used in the post isn't all that "fall out of your chair". Here is the same implemented in pure JS using my toy IO.js library - [https://gist.github.com/srikumarks/5992336](https://gist.github.com/srikumarks/5992336)

<comment><AUTHOR> People keep focusing on the first example. If you're going to compare, I think it's much more illuminating to see versions of the final example.

<comment><USER15> Challenge accepted.

[https://gist.github.com/srikumarks/5992608](https://gist.github.com/srikumarks/5992608)

<comment><AUTHOR> Thanks!

</comment></comment></comment></comment></comment><comment><USER16> Very cool - I didn't realize that core.async has made it into ClojureScript. Seems more like a viable language for web programming every day.

<comment><USER17> In your opinion, what is missing that it needs to become viable?

<comment><USER16> The last time I tried it I didn't find a broadly accepted server-side framework that automatically compiles ClojureScript assets, but I haven't looked in a while.

<comment><USER18> Why wouldn't you just deploy the compiled js as a static asset? If you want to autocompile it while developing, leiningen + cljs-autobuild handle that well.

<comment><USER16> I was looking for some server-side framework for also handing HTTP requests and REST calls

<comment><USER19> You might want to take a look at Liberator [http://clojure- liberator.github.io/liberator/](http://clojure-liberator.github.io/liberator/)

</comment></comment></comment></comment></comment></comment><comment><USER20> Great post!

And here's a todo's example that I wrote [https://github.com/bhauman/async- explore/blob/master/src/tod...](https://github.com/bhauman/async- explore/blob/master/src/todos_first/core.cljs)

</comment><comment><USER21> Why do you call alts! input choices as non deterministic ?

<comment><USER22> You won't know _which_ channel is going to give you a value ahead of time, it depends on runtime conditions.

But really, you don't care if the user pushes the keyboard or moves the mouse first, you just want to handle each event as it happens in essentially a sequential manner.

<comment><USER21> If I am forcing it to be sequential, aren't the choices now determinitic?

<comment><USER23> The default for multiplexing is non-deterministic choice. You can specify the :priority flag [1] if you want deterministic choice when multiplexing. Reads and writes will block for a non-deterministic amount of time, but their sequencing will be deterministic. That's the beauty of the CSP model: You can achieve some level of local determinism within a particular thread of control. Makes it much easier to reason about the non-deterministic outside world.

[1]: [https://github.com/clojure/core.async/blob/bb77337b3e9ce2118...](https://github.com/clojure/core.async/blob/bb77337b3e9ce2118916fe84ae37c064a2eb9c55/src/main/clojure/clojure/core/async.clj#L229)

<comment><USER21> makes sense , thank you!

</comment></comment></comment></comment></comment><comment><USER24> Obligatory Hoare link: [http://usingcsp.com/cspbook.pdf](http://usingcsp.com/cspbook.pdf)

</comment><comment><USER25> the article is a bit of a cheap shot against Typescript. They have had async in the roadmap the last 6 months at least (and the public project is only about 10 months old).

IIRC, async is the next big feature on the roadmap, and going to be in before v1.0 (v0.9, released 2 months ago, added generics)

given the pace of development, typescript v1 should be done in 6 months or less.

<comment><USER26> I don't see how that makes it a cheap shot. Everyone is drawing from the same pool of ideas that were discovered decades ago. Could you be more specific?

<comment><USER25> typescript is very popular for how young it is. so given that the thing is still a very young, alpha product, saying that they are neglecting feature X is a bit too much. better to just not even mention it.

<comment><USER26> Yeah, the rhetoric at the beginning is a bunch of cheap shots at different languages. Having said that, it is clearly separated from the rest of the post by the line: _Enough rhetoric, let 's see how core.async works in practice._

As for language features? core.async is not a feature of Clojure/ClojureScript; it's merely a library.

</comment></comment></comment></comment><comment><USER27> If you're interested in this sort of thing, also take a look at MenTaLguY's WebActors:

[https://github.com/mental/webactors](https://github.com/mental/webactors)

<comment><AUTHOR> Yeah I've seen this before though it doesn't really allow you to share arbitrary data as it relies on Web Workers (if you share data with a worker it will disappear from the sending process). I'd also be concerned about the performance of the implementation, core.async adopts C#'s approach which is pretty light weight.

</comment></comment><comment><USER28> Where does the blog style come from ?

<comment><USER20> I'm pretty sure it's standard jekyll [http://jekyllrb.com/](http://jekyllrb.com/)</comment></comment>


Ask HN: Predicted YC S14 Interview Dates? - <AUTHOR>

I'm trying to figure out a rough date for when the S14 interviews will take place. The app says that companies will be invited out on the 15th of April, but it does not specify when the actual interviews take place. Historically, what have been the interview dates for previous batches? <comment><USER2> "On April 15, we'll invite the groups that seem most promising to meet us in Mountain View between April 24 and 28. "

</comment><comment> mark-bain I'm also impatiently awaiting your today decision! So excited ;)</comment>


Chrome Extension says "it can read my data in all the website I visit" - <AUTHOR> Will these extensions can read my passwords ? what do you all feel about this. How safe are any chrome extensions <comment><USER2> You can read the source and see for yourself. I use an extension called CRX viewer [0] to unpack extensions and view their source before installing them. When you're in the extensions store you just click the button and it shows you the source.

When inspecting the source I grep for http/network calls and anything that looks suspicious. Most extensions are fairly simple and it's easy to see when they're not malicious.

Problem is, those extensions can update their source at any time. Ownership can change. A good extension can turn malicious while you aren't looking. For that reason, if I really need an extension with "all website" permissions, I make sure to disable it and only enable it when I use it.

The only long running extension with those permissions on my machine is uBlock.

[0] [https://chrome.google.com/webstore/detail/chrome- extension-s...](https://chrome.google.com/webstore/detail/chrome-extension- source-v/jifpbeccnghkjeaalbbjmodiffmgedin?hl=en)

<comment><AUTHOR> why an extension needs all website permission, even then can't google provide a mechanism to avoid password fields out of scope of access. Is there a reason why it is not done ? technically speaking.

<comment><USER2> Lazy developers, that's all there is to it.

And of course some extensions do need access to the whole page, including password fields. For example a password manager obviously needs access (though it shouldn't need to read the password field, only write to it).

As to why it's not possible to have super granular permissions (i.e. restricting to certain elements on the page) — that would break the whole extension model, because scripts you inject into the page would have to operate on a "shadow DOM" of sorts. Also properly sand boxing within a single DOM would be porously impossible.

Now that I type it out though, I could see how maybe it would be possible to construct a restricted, parallel DOM for an extension to interact with... but I really don't think the complexity is worth changing the status quo.</comment></comment></comment>


Who is using Semantic Web technology in production? - <AUTHOR> Semantic Web movement has produced several technologies (JSON-LD, SPARQL, OWL, etc) that seem useful for data integration, but they don't appear to have much momentum. I'm struggling to determine if the Semantic Web is a justly abandoned bad idea or a quietly useful mature technology.<p>The main place I see Semantic Web technology in use is SEO [1] and Email Markup [2]. Is anyone using these technologies for more general data integration tasks?<p>[1] https://www.bing.com/webmaster/help/markup-validator-e9b66817<p>[2] https://developers.google.com/gmail/markup/getting-started <comment><USER2> Here is my take on what RDF is

[http://ontology2.com/the-book/rdf-a-new-slant.html](http://ontology2.com/the- book/rdf-a-new-slant.html)

JSON-LD and SPARQL are fine, OWL as an inference system has some good ideas (implementable by macros on top of production rules) but it is not adequate to do what people need for data integration (multiply, divide, add, subtract for one thing.)

<comment><AUTHOR> Thanks, that's a solid resource that I wasn't aware of. It's interesting how you're generating Java stubs using your K Schema format.

I like the idea of using RDF as a universal data model. I buy the power of graphs in general, and RDF seems much more useful than a generic object- property graph thanks to built in support for namespaces and reasoners.

My hesitation about the concept comes from concerns around performance and implementation difficulty. It looks like you've built some solid tools to ease the initial modelling challenge, how are you addressing the performance challenges? That is, once you pull several data sources into a huge graph, how do you keep query speed up?

<comment><USER2> The "huge" graph is only virtual. It exists in principal but you are not going to materialize the whole thing when it gets huge. Or if you are you are going to do it with stupid Hadoop methods, not by trying to grow traditional databases up.

Trying to get the whole world inside one "envelope" is scalability pornography, i.e. SAP HANA.

Realistically you create the indexes and data structures necessary for your workload, it is not that different from any other technology except in the case of RDF the math is known.

</comment></comment></comment><comment><USER3> All of our customers; see [http://stardog.com/](http://stardog.com/) for the notable ones. (Hint: it's a quietly useful mature technology.)</comment>


Ask HN: How are Google's "Chrome webapps" different from IE-specific websites? - <AUTHOR>

<comment><USER2> Chrome uses webkit, which is open source and is used by safari and iphones, and androids too I believe.

Webkit is opensource and is rapidly evolving; it's basically pushing the edge of what the web can do.

Totally different from IE. A closed, old, non-standard browser only used by people not savvy enough to know what a browser is, and most importantly, it's holding the web back.

</comment><comment><USER3> I believe chrome is fairly standards-compliant, which IE is not. So your app will be more portable.

</comment><comment><USER4> I don't like "webapps" in general. I prefer command-line programs</comment>


This nasty new Android ransomware encrypts your phone – and changes your PIN - <AUTHOR> http://www.zdnet.com/article/this-nasty-new-android-ransomware-encrypts-your-phone-and-changes-your-pin/ <comment><AUTHOR> Better URL:

[https://www.welivesecurity.com/2017/10/13/doublelocker- innov...](https://www.welivesecurity.com/2017/10/13/doublelocker-innovative- android-malware/)</comment>


Cave paintings change ideas about the origin of art - <AUTHOR> http://www.bbc.com/news/science-environment-29415716 <comment><USER2> It's worth remembering in the case of discoveries like this that the oldest instance of the practice is almost certainly far older than the oldest preserved instance of the practice.

Unfortunately, there has been relatively little statistical work done to use distributions of preserved ages to infer the age of origin, and although I recall reading an article in Nature on the problem in the '80's or early '90's it would seem that most of the people working in the field have not really focused on this problem, and instead continue to apply a mixture of "The practice began around the time of the earliest preserved instance of it" and "The practice began earlier by some amount that I will estimate from my gut".

Neither of these is approaches is methodologically sound, and both tend to underestimate the ultimate age of a given practice (or species, in the case of fossils) and tend to underestimate the error bars as well.

<comment><USER3> A good point. I would just quibble with your affirmative statement that '... the oldest instance of the practice is almost certainly far older than the oldest preserved instance of the practice.'

It seems to me that whilst it is highly likely the first instance is earlier than the first discovered instance and that this is a perfectly valid conjecture I don't think we have any convincing grounds to state that it is 'almost certainly far older.'

</comment></comment><comment><USER4> I am reminded of Steely Dan's "The Caves of Altamira" ([http://www.youtube.com/watch?v=pt9VCuAbRxc](http://www.youtube.com/watch?v=pt9VCuAbRxc)), a meditation on cave paintings, and other artifacts of the human drive to create visual art, such as movies, that are shown on the walls of a darkened chamber, for our delight.

</comment><comment><USER5> As always, Herzog's Cave of Forgotten Dreams is topical: [http://en.wikipedia.org/wiki/Cave_of_Forgotten_Dreams](http://en.wikipedia.org/wiki/Cave_of_Forgotten_Dreams)

I showed it to a couple of my friends and every one of them fell asleep. I liked it though, and it gives you an interesting look into the modern day behind-the-scenes work these immensely valuable discoveries bring forth.

<comment><USER6> A good movie, and the only movie I've seen in 3D that benefited from 3D. You can see how the painters used the shape of the walls in their painting.

</comment></comment><comment><USER7> The "Interactive Video" on this page is hilariously ill conceived. Once you click a link to start another video you can't jump back to the original video and you end up playing two videos at the same time. The presenter says "Click here" but the "link" is already gone before you can even move your mouse.

<comment><USER8> Did you notice that the volume in the player goes to 11?

</comment></comment><comment><USER9> Can you imagine standing next to "one of the oldest figurative depictions in the world, if not the oldest one?"

The philosopher Walter Benjamin spoke of certain artworks having "aura." That one practically glows.</comment>


Ask HN: Pros and Cons of Using .NET CMS vs. PHP CMS - <AUTHOR> Over the years I have built websites on both types of platforms. I am trying to form an unbiased report to see which one would be a better fit. The project description is - to have a website that the cms is very easy to use (So non technical users can easily add and update content), that is very secure, future development on the project will be as straightforward as possible (This obviously depends on how its built but one will be easier than the other, e.g adding new templates, campaigns, functionality and such), maintenance will be simple as possible. I have a preference from over the years, but I'd like a wide range of views and experiences to form an unbiased opinion. Which ever is used, the cms used will be open source. <comment><USER2> The most popular CMS is WordPress. Is there a .NET CMS that you feel has more functionality than WordPress? Perhaps your site will be in a domain for which a .NET CMS would have some advantages?

<comment><AUTHOR> The project would be for a large company with a focus on security. Also, the CMS would have to have bespoke functionality, so an out the box solution wouldn't work for us</comment></comment>


Our Approach to Employee Security Training - <AUTHOR> https://www.pagerduty.com/blog/security-training-at-pagerduty/ <comment><AUTHOR> PagerDuty recently open sourced their security training platform, slides and all. It's very complete and written for the common employee. Recommended!</comment>


Darpa wants your gaming tactics for its drone army - <AUTHOR> https://www.engadget.com/2016/12/12/darpa-wants-your-gaming-tactics-for-its-drone-army/ <comment><USER2> This AI-as-a-competition is somewhat troubling to me (Kaggle, that hedge fund yesterday, now Darpa). You are building value for someone without knowing the true value for someone else. The free market aspect is great. Many competitors from poorer countries, thus really inclusive. Often the organizers get great value from competitions.

But heck, building the AI that will lay waste to your stockmarket or country at a algorithmical whim. Hmm, perhaps ethically better to let defense projects fail on their own via failed incentives than crowdsource them into something 'great'.</comment>


Google+ Birthday: Google+ is now 3 Years Old (Stats in Infographic) - <AUTHOR> http://inspirationmind.com/google-plus-birthday-infographic/

<comment><USER2> Wow! One year for every person who uses it</comment>


17-16783 HiQ Labs, Inc. V. LinkedIn Corporation - <AUTHOR> https://www.youtube.com/watch?v=tvLdJujOp8k <comment><AUTHOR> this is an incredibly interesting case. Highly recommend anyone involved with public data to watch this video.

Note: Mods - I submitted this late at night, but if you could bump this to front page tomorrow, I'm sure it would be very useful watch for many startup founders/employees :)</comment>


Asset Pipeline Tips - <AUTHOR> http://icelab.com.au/articles/asset-pipeline-tips/

<comment><USER2> +1 for AssetSync and S3 hosting when you're running an app on Heroku. I wouldn't do it any other way anymore.</comment>


The Complexity of Simplicity - <AUTHOR> http://uxmag.com/articles/the-complexity-of-simplicity

<comment><AUTHOR> Thanks Jay Selway, you wrote down exactly what I've been thinking.</comment>


Ask HN: Share Your Raspberry Pi Project - <AUTHOR> I'm looking for some inspiration for what I can do with my $35 computer. I think we can all learn a lot from any cool hardware project. <comment><USER2> Although not strictly a Raspberry Pi project, I have a couple C.H.I.P. boards[1] scattered throughout my apartment collecting temperature and humidity readings (using a HIH8120 sensor[2]) and feeding it to my Raspberry Pi which runs InfluxDB and Chronograf[3] to store and display a simple dashboard. The end result looks like this: [http://i.imgur.com/cIrhSUq.png](http://i.imgur.com/cIrhSUq.png)

[1]: [https://getchip.com/](https://getchip.com/)

[2]: [https://sensing.honeywell.com/HIH8120-021-001S-humidity- sens...](https://sensing.honeywell.com/HIH8120-021-001S-humidity-sensors)

[3]: [https://www.influxdata.com/time-series- platform/chronograf/](https://www.influxdata.com/time-series- platform/chronograf/)

<comment><USER3> What language did you end up using to access the sensors?

I've been ~hoping~ to use Go to access the GPIO pins, but haven't had much success - any suggestions?

<comment><USER4> I've used [https://github.com/stianeikeland/go- rpio](https://github.com/stianeikeland/go-rpio) to control my garage doors and this library [https://github.com/kidoman/embd](https://github.com/kidoman/embd) has some more advanced features which I've used for a thermostat solution.

<comment><USER3> Thanks! I'll take a look! I have an AstroHat on my Pi and I think it should be straight forward-ish using one of these.

</comment></comment></comment></comment><comment><USER5> I used one to build a photobooth for my wedding. The raspberry pi controls a DSLR camera to take 4 photos, stitches them into a 4x6, prints the photo and uploads everything to a Google Photos album which was displayed live on a projector.

<comment><USER6> I would be insanely interested in a thorough write-up of this. My mother is getting married in a few months and it would be incredible to build for her and her fiance!

<comment><USER5> I'll try and get the process written down but in the meantime, feel free to shoot me an email with any questions. You can find my email in my profile.

</comment></comment></comment><comment><USER7> I built a microtonal keyboard: [http://jsnow.bootlegether.net/jik/keyboard.html](http://jsnow.bootlegether.net/jik/keyboard.html)

The keys have pressure sensitive film underneath that causes a voltage drop when you press on them. There's a wire from under each key that goes to an input on an MCP3008 ADC. There are 20 of those, each with 8 inputs, all connected on a SPI bus running at 2mhz. Effectively, this acts as a 160 channel digital voltmeter. The Pi can scan all the ADCs about 90 times per second, and it converts key pressure into midi commands that can be sent to an external synth or I can run a software synth locally on the Pi.

<comment><USER8> That's a beautiful piece of work. Nice job!

<comment><USER7> Thanks.

</comment></comment></comment><comment><USER9> I brew beer with mine[1]. I use a CHIP to control an old fridge as a fermentation chamber.

For both systems I'm using CraftBeerPi[2], a python project with a pretty active community around it.

I wrote about it on opensource.com[3] and it was pretty popular, which surprised me a little bit. But I guess a lot of people in our community like beer :). I'm always trying to figure out how to make brewing my career without the related massive cut in income (please share any great ideas on that!)

[1]: [http://localconspiracy.com/2016/12/electric- brewery.html](http://localconspiracy.com/2016/12/electric-brewery.html) [2]: [https://github.com/Manuel83/craftbeerpi](https://github.com/Manuel83/craftbeerpi) [3]: [https://opensource.com/article/17/7/brewing-beer-python- and-...](https://opensource.com/article/17/7/brewing-beer-python-and- raspberry-pi)

<comment><USER10> Fellow beer brewer here!

I wrote my own small weather service, [http://www.brilcast.com/](http://www.brilcast.com/), and re purposed the waterproof sensor to help track and record the process from lautering/sparging all the way to transfer to primary fermentation.

The setup is simple. Sensor code is written in Python, then it's sent to a SQLite database running on a Flask webserver. The frontend uses D3.js to visualize the data. The entire service is hosted on Pythonanywhere. It's quite spartan, but it works well. [https://github.com/williamBartos/brilCast](https://github.com/williamBartos/brilCast)

</comment></comment><comment><USER11> I built a spaceship for my kids: [http://www.duncanjauncey.com/blog/archives/377](http://www.duncanjauncey.com/blog/archives/377) (please excuse the tabloid headline of the article)

<comment><USER12> You Win Father of Year in my book.

</comment></comment><comment><USER13> Recreating the Sony Aibo robot dog using a pile of cheap servos, 3 axis gyro, the camera, wireless, neopixel lights, LiIon power, etc. Shoulder joints, body shell and chassis 3d printed. Total cost is around $150.

Locomotion is largely based upon the designs documented by Cynthia Brezeal Ferrell (MIT mobile robots lab, under Prof. Rod Brooks) in her PhD thesis for the hexapod robot, Atilla/Hannibal.

The first attempt was using Python which presented two insurmountable problems : 1) raspian OS boot time of 1.5 minutes which is unacceptable for an embedded device and 2) python threading is not sufficient for realtime. I was attempting to make series elastic actuators but the imprecision of the threading (jitter) was leading to wild oscillations... I finally had to accept it was a dead end.

I have started over in Elixir + Nerves which is designed at its core for embedded work. I will admit it is very slow going. Not because of any deficiencies in the language or environment. Quite the contrary -- I get a 10-second cold boot time and superb stability! But rather my mind is the limiting factor here. After three decades of imperative programming, the shift to functional programming is a challenge!

<comment><USER14> Any pictures, write up, Github? This sounds awesome!

I also remember reading awhile back about the huge market for upkeeping these things once Sony abandoned it. Perhaps you're onto a business!

<comment><USER13> No, this is the first I've spoken of it, really. I've a few notebooks filled with sketches, thoughts, designs, etc. and a pile of prototype joins and brackets littering my workbench. It's actually a very challenging project from an electrical engineering and mechanical engineering standpoint. The Sony team were superstars. I still like the "mutant" prototype the best as it had the most character: [https://www.youtube.com/watch?v=gfHape9Y31Q](https://www.youtube.com/watch?v=gfHape9Y31Q)

In the mid 2000s, I had written some code for the Aibo to let it read books aloud.

Flash forward toa couple years ago. My kids saw some video of me with the Aibo Reader project and wanted an Aibo of their own. Unfortunately, the Aibo as a product is dead. The batteries are now dying and irreplaceable (thanks to Sony and their idiotic insistence upon DRM - it's not enough to merely provide electrons, the battery must also know the secret handshake in order for the Aibo to accept it. Maddening!!!) And those few used Aibos that do have working batteries are dying from other issues related to mechanical failure (mostly clutches in the head/neck assy.) yet command a premium price.

So now, my kids still want an Aibo. I got to thinking about how far technology had come in the past 20 years, and started wondering to myself if I could build a facsimile with the RPi. Thus the birth of this little side-project.

</comment></comment></comment><comment><USER15> Use Home Assistant to integrate anything in your house. Make voice assistants respond to your commands. Write advanced automations to help make your life easier.

Use our Hass.io OS build to setup Google Assistant easily on your Pi. Need a USB microphone and speakers connected to the Pi and you'll get the full Google Assistant experience.

[https://home-assistant.io](https://home-assistant.io)

(disclaimer: I'm the founder)

<comment><USER16> I've been really digging home-assistant. Just got it set up a few weeks ago. Ended up buying $300 of zwave switches soon after

</comment></comment><comment><USER17> I'm the co-founder of [https://snips.ai](https://snips.ai), we are building a 100% on-device Voice AI platform to respect people privacy!

We would love to see what you can do with what we are building and to feature you on our website !

<comment><USER14> I've done a little reading into making something along these lines using a Pi, Snowboy hotword detection, and one of the cloud APIs.

Two things I'm curious about...

1) What are you using for hardware with the Pi? It seems a high quality microphone is important to this application and the only array microphone I've been able to find is the MATRIX creator which seems steep in price if I could just buy an Amazon Dot.

2) Your numbers indicate significantly better performance than Google. How are you able to achieve that? Where does your training data come from if nothing is supposedly leaving my device?

I really strongly desire a system that wouldn't require relying on the cloud but I just don't know how you can get enough training data to be anywhere near as accurate as a cloud provider. That led me to thinking the next best thing would be a setup with Snowboy hotword detection where I know nothing is leaving my device until my own programmed hotword is spoken.

<comment><USER17> Hi Bronco, a blog post on microphone will come soon on our blog, subscribe!

</comment></comment></comment><comment><USER18> Me and My brother made a strobe light based on a Nature paper to attempt to treat my Uncle for Alzheimers.

See [http://www.nature.com/nature/journal/v540/n7632/full/nature2...](http://www.nature.com/nature/journal/v540/n7632/full/nature20587.html?foxtrotcallback=true)

<comment><USER19> Do you have any more information about your project?

<comment><USER18> Yes, I think I prodded my brother to write a blog post but I will write it myself and try to get to it this weekend.

But basically the steps you would have

1\. Get a Raspberry pi (obviously) and load linux with python support.

2\. Use this shield [https://www.amazon.com/Pimoroni-Unicorn-Hat-Shield- Raspberry...](https://www.amazon.com/Pimoroni-Unicorn-Hat-Shield- Raspberry/dp/B00RTQEP7M/ref=sr_1_4?ie=UTF8&qid=1501164329&sr=8-4&keywords=raspberry+pi+led+shield)

3\. Create a python script that blinks with the HZ that was in the Nature paper.

<comment><USER20> I think I saw someone else try a similar thing with an oculus rift or vive. How do you think it went with your relative.?

<comment><USER18> I have no idea. We never did any controlled experiments. Also, I didn't notice a difference anecdotally.

</comment></comment></comment></comment></comment><comment><USER21> We've built a whole business on top of the Raspberry Pi. The company/project is called Screenly[1], which is a digital signage solution for the Raspberry Pi and we have over 10,000 devices running it. We really gained a lot of momentum early on with our open source version[2].

[1] [https://www.screenly.io](https://www.screenly.io)

[2] [https://github.com/Screenly/screenly- ose](https://github.com/Screenly/screenly-ose)

<comment><USER22> Interesting product. Are there any screenshots / videos of it in action?

</comment></comment><comment><USER23> I built a tool that monitors a solar panel installation:

The Website: [http://solarpi.tafkas.net](http://solarpi.tafkas.net)

Github Repository: [https://github.com/Tafkas/solarpi](https://github.com/Tafkas/solarpi)

Blog Post: [http://blog.tafkas.net/2014/07/03/a-raspberry-pi- photovoltai...](http://blog.tafkas.net/2014/07/03/a-raspberry-pi-photovoltaic- monitoring-solution/)

Feedback is very welcome.

</comment><comment><USER24> I've always liked chiming clocks, so I made a pseudo grandfather clock with an RPi Zero W, a $1 I2C servo controller, and a $3 mini digital servo that strikes a long chime tube scavenged from an old doorbell[1] - ntpd means it's a lot more accurate than a pendulum clock, and cron keeps it from ringing in the middle of the night.

1: [https://youtu.be/mfOEBCp74UU](https://youtu.be/mfOEBCp74UU)

</comment><comment><USER25> I built a tube internet radio with speech output of station names and switching stations with the AM dial. A small USB mouse picks up the rotation, a python script speaks the station name and passes the stream URL to gmediarenderer. Sound via USB soundcard and Phono/Aux input. Inspired by [http://blog.scphillips.com/posts/2014/05/playing-music- on-a-...](http://blog.scphillips.com/posts/2014/05/playing-music-on-a- raspberry-pi-using-upnp-and-dlna-v3/).

Some pictures at [http://imgur.com/a/r834D](http://imgur.com/a/r834D)

<comment><USER26> Any info re: interfacing with the dial? I bought a radio for a similar purpose that's just been gathering dust in the garage.

<comment><USER25> Sure. I'm reading this device [https://www.google.de/#q=PX8559+mouse](https://www.google.de/#q=PX8559+mouse) with code similar to that one: [https://stackoverflow.com/questions/4855823/get-mouse- deltas...](https://stackoverflow.com/questions/4855823/get-mouse-deltas-using- python-in-linux)

Measure, how many delta ticks a revolution gives you and adjust the delta to trigger the next station to feel natural when turning the dial. I bent a simple bracket from some scrap sheet metal to hold the mouse in place just above the dial. The black and white threads of the cord wrapped around the dial helps the optical sensor, so try to position the optics above that.

Similar project: [https://2dom.github.io/the- radio/](https://2dom.github.io/the-radio/) I did not bother to remove parts of the mechanics to make the dial endless, however. Dialling through so many stations that you need that is tedious anyways, so I felt I don't need it.

Oh and by the way, I made the Raspi's filesystem read-only so I could shwitch it of safely with the radio. See i.e. [https://hallard.me/raspberry-pi-read- only/](https://hallard.me/raspberry-pi-read-only/)

</comment></comment></comment><comment><USER27> 1\. use it as a weather station - temp/hum/pressure sensors are quite cheap 2\. if you already have weather station, hook it up to an API and share the data (wunderground.com, or similar) 3\. you can use it as local lan media player/web server if you don't want to mess with hardware 4\. build a bad ass robot/drone/submarine with it 5\. build security system - possibilities are limitless. You can even use pressure sensor as intrussion detection device, let alone sound, light, shock, camera, IR, etc sensors.... 6\. use it as an alarm clock 7\. use it as decoration - if you need it to last forever, pour a resin in a mould over it 8\. wrap it as a gift if everything else fails

<comment><USER17> Cool! If you want to add 100% on-device Voice AI to your weather station you can use our platform at [https://snips.ai](https://snips.ai) which is free and will be open-sourced later!

</comment></comment><comment><USER14> Nothing unique really but I have a handful of older ones laying around that used to be purposed as RaspBMC machines. I recently moved everything to Plex with different client devices so I repurposed one Pi to be a print server for my parent's older printer. Another one has been repurposed as an AirPlay client for my outdoor speaker setup using a cheap amp I bought on Prime day.

I also have a newer Pi 3 running Stratux for receiving ADS-B traffic and weather on my iPad while flying.

Aside from Stratux there are definitely cheaper/easier solutions for what I've set up but nothing beats the 'free' hardware collecting dust in the bin.

</comment><comment><USER28> I've built my home automation setup around Raspberry Pis.

I have an old Nexus7 tablet mounted on the wall (3D printed wall mount which incorporates a wireless charging coil) which hits the web UI of NodeRED running on a Pi to provide a 'home control panel'.

There's a pi with a heap of relays which controls things like my garden lights, sprinklers, motorised curtains (3D printed adapters to convert standard curtain tracks into motorised ones), etc, and then I have a number of Orvibo S20 WiFi power sockets to switch things like lamps on and off.

I have a pi mounted behind the front entrance panel acting as a doorbell, also connected to a camera module which triggers push notifications etc when motion is detected. This also ties back into the main 'automation hub' via NodeRED.

I also built an aquarium monitoring/control system on another Pi, with ambient and water temperature probes, a bunch of relays turning filters, lights, heaters, pumps, etc on and off, and an IR-emitter to send the relevant commands to my lighting fixtures to control the colour temperature and intensity (providing a 'sunrise'/'sunset' effect). Again, this all ties back to the main system using NodeRED.

Unrelated to the home automation, I also use a Pi to manage and run my 3D printer using OctoPrint, and run my media centre using LibreElec/Kodi/Emby (with my media stored on my main workworkstation and served via Emby).

<comment><USER29> Can you give some more information on the 3d printed blind automations? I've got a house with a lot of windows and I'm looking for an unobtrusive and cheaper way to automate all of the blinds

</comment></comment><comment><USER30> Here's an open hardware robot arm you can build:

[http://kickstarter.com/projects/mime/mearm-pi-build-your- own...](http://kickstarter.com/projects/mime/mearm-pi-build-your-own- raspberry-pi-powered-robot/)

I know it's Kickstarter but it will be shipping very soon and you can already download the files to cut your own if you're into that.

(Disclaimer: it's my project!)

</comment><comment><USER31> Maybe not useful (to anyone else at least), but I've built a couple of small wheeled robots with cameras to do some experiments with Computer Vision.

Unless you're doing computationally intensive tasks, I find a Raspberry Pi 3 is overkill. If you go with the cheaper models like one of the low end Orange Pi's, you don't mind dedicating them to projects, even if the project is pretty useless.

</comment><comment><USER32> I recently used a Pi to replace the game controller on an arcade style basketball game we have in our office (like this: [http://imgur.com/a/B7YBq](http://imgur.com/a/B7YBq)). It's running Android Things and has a couple of fun new game modes, better sound effects, and a whole bunch of LEDs for added awesomeness.

</comment><comment><USER33> I use my raspberry pi to run home assistant to control my IoT devices. I also have another pi mounted on my 3d printer running octoprint so I can remotely interact with the printer.

<comment><USER17> If you are using Home Assistant, you can now do your own on-device Voice AI for free using [https://snips.ai](https://snips.ai), we have added an integration!

</comment></comment><comment><USER34> I have one running a few home automation type tasks (an IP->serial gateway for my whole-house audio, SDR radio to monitor 4 utility meters [only 2 meters are currently reporting data as my 2 water meters are not reporting usage via radio to me or to the utility], and controlling relays for the sprinkler system). Next steps are I plan to create an Alexa skill that will control the whole-house audio and let me "pause" the sprinklers as needed and integrate with weather forecasting to predict near-future rainfall so I can save water/increase plant health if rain is expected.

I'll be honest: it's a lot of fun, but if I lived 100 lifetimes, it would never save me time on balance. ;)

I also use one to run stratux as another poster mentions. That one saved ~$650 vs buying the COTS solution.

<comment><USER14> Curious about your SDR meter monitoring. Any links or description of how that works? Would love to monitor my electric and water without using the energy company's devices.

<comment><USER34> I didn't do any actual hard work. I just used rtl-amr, which was super-easy to grab, compile, and use.

[http://bemasher.net/rtlamr/](http://bemasher.net/rtlamr/)

[http://bemasher.net/rtlamr/signal.html](http://bemasher.net/rtlamr/signal.html) has information on how it works, but you don't need to do/know anything about the protocol to get it to work.

</comment></comment></comment><comment><USER35> I use it as a remote on/off/reset switch hooked directly to the mobo of my windows pc for when it decides to crash/bsod/random stuck and i can't RDP into the box, or just the power went out and need to turn the pc back on if it didn't automatically.

</comment><comment><USER36> DeckLights !

With an LED strip, some carpentry, an Arduino, and rpi, I've brightend up my deck a little bit. The rpi is there to program the arduino while embedded and to have a web interface to control the lights. Still to do was to get Homebridge (which is working on the rpi) to turn the lights on and off using Siri.

[http://imgur.com/a/E4lbU](http://imgur.com/a/E4lbU)

[https://www.youtube.com/watch?v=ww1q248jc7Q](https://www.youtube.com/watch?v=ww1q248jc7Q)

[https://github.com/kejaed/deckLights/blob/master/projectNote...](https://github.com/kejaed/deckLights/blob/master/projectNotes.md)

</comment><comment><USER37> Just yesterday I used an old raspberry pi to make a bluetooth audio receiver that could be integrated with my vintage stereo equipment. You can buy something off the shelf for around $25 but they use cheap digital-to-analog converters and I wanted to use the high quality USB DAC I already had. Total hardware needed was the Pi, powered USB hub, USB DAC, and USB bluetooth adapter.

Potato quality photo of the very advanced system I came up with for keeping all the components together: [https://tootcatapril2017.s3-us- west-2.amazonaws.com/media_at...](https://tootcatapril2017.s3-us- west-2.amazonaws.com/media_attachments/files/000/145/034/original/b49915978159c460.jpg)

<comment><USER38> Did you have to use the USB bluetooth adapter with a Pi 3? I know the 3 has bluetooth but I don't know enough about it to know if I can just connect my phone to it to play music. I want to do something very similar to what you've done so I'm excited to see that somebody else succeeded.

<comment><USER37> I used the very first version of the Raspberry Pi model B. I bought one when they became available years ago and then never did anything with it. If the Pi 3 comes with a bluetooth chip built-in then you will just need to do some software configuration. There are three servers to configure: bluez, udev, and pulseaudio. I used the following gist as a guide, but didn't follow every step exactly:

[https://gist.github.com/oleq/24e09112b07464acbda1](https://gist.github.com/oleq/24e09112b07464acbda1)

Hope this helps!

</comment></comment></comment><comment><USER39> I'm working on simplifying live streaming from the Raspberry Pi to Periscope [1] using the Camera Module [2]. Future streaming targets include the usual suspects: Twitch, YouTube, Facebook Live, et al. Deployment is flexible; you can install it as a Debian package, a Docker image, or a standalone binary.

Personally, I plan to use it as a traffic camera mounted on the window of our office.

[1] [https://github.com/schmich/piriscope](https://github.com/schmich/piriscope)

[2] [https://www.raspberrypi.org/products/camera- module-v2/](https://www.raspberrypi.org/products/camera-module-v2/)

</comment><comment><USER40> Some friends and I built a jukebox with lights that react meaningfully to the chords and beats in the music (using Chordify). We brought it to Burning Man as an art project. It's nothing compared to the other crazy ambitious stuff people do there - but it was our first real electronics project, and we had to learn a lot as we went.

Here's a grainy video: [https://youtu.be/sXVZhv_Xi0I](https://youtu.be/sXVZhv_Xi0I)

Here's the code: [https://github.com/nick264/music-processor- master](https://github.com/nick264/music-processor-master)

</comment><comment><USER16> I had one on my sailboat making all the boat's sensor data available over wifi. It also let me control the Raymarine AutoHelm from my iPhone.

[https://github.com/johnboiles/Helm- firmware](https://github.com/johnboiles/Helm-firmware) [https://github.com/johnboiles/Helm- hardware](https://github.com/johnboiles/Helm-hardware) [https://github.com/johnboiles/nmeaproxy](https://github.com/johnboiles/nmeaproxy)

<comment><USER41> Damn, now I have a legitimate reason to buy a sailboat ;)

</comment></comment><comment><USER42> Built a working prototype of a LAN based discovery and routing device for Evercam.io. Not very sophisticated but it worked and it was deployed to several locations successfully in a pilot program, allowing them to route to Cameras that were otherwise inaccessible.

Actual code didn't rely on rPi (Elixir/OTP on Linux). But we shipped them on Pis. Other options considered had been Galileo and also an SoC called (I think) Quark (also from Intel).

[https://gitlab.com/evercam/evercam- gateway](https://gitlab.com/evercam/evercam-gateway)

</comment><comment><USER43> I used it to built a working prototype of Spot [1], a Raspberry-Pi powered chatbot that helps people find a parking spot. As a test, the RPI3 was mounted on the lightpost, the Camera Module [2] was used to capture images, so we can count number of empty spots.

[1]: [https://github.com/tzano/spotFinder](https://github.com/tzano/spotFinder)

[2]: [https://www.raspberrypi.org/products/camera- module-v2/](https://www.raspberrypi.org/products/camera-module-v2/)

</comment><comment><USER44> I'm running a digital signage service based on the Raspberry Pi: [https://info-beamer.com/](https://info-beamer.com/)

It started as a for-fun project and I'm now working full time on it. So I guess it qualifies :-)

If you want to display any kind of information on your Pi, you might take a look. The code that "runs" the display is written in Lua and the system is pretty programmer friendly. You can even 'git push' and deploy directly on any number of screens. Questions welcome!

</comment><comment><USER45> I'm using a Pi to capture the speeds and pictures of cars as they travel down my road. We then report the speeders to local law enforcement. I recently decided to expand to a 9 camera system (8 security cameras and 1 piCamera) and start capturing video, stills, speeds and car data. I then am able to show that the same car speeds everyday (or however often) and have a lot of useful data to hand over. My next step is to mount a large display on my property that shows the cars in big numbers just how fast they are going.

<comment><USER20> I bet a screen showing their behaviour is more effective than reporting them to the police.

<comment><USER45> actually the reporting to local law enforcement has been very effective. They do extra patrols based upon the data and have issues a number of tickets.

One they issued a ticket for 80 in a 35 to a driver at 5:00am and then again the next day the driver did the same thing! Didn't expect them to be there two days in a row.

<comment><USER46> You might have saved his life - or someone else's. 80 in a 35? Completely insane.

<comment><USER45> Yeah and sadly these high speeds are common in our rural area. Drivers see a long 2 lane road in the middle of nowhere and just press the gas.

</comment></comment></comment></comment></comment><comment><USER47> I built a remote controlled cat feeder with a simple servo controller loosely based on this blog: [http://drstrangelove.net/2013/12/raspberry-pi-power-cat- feed...](http://drstrangelove.net/2013/12/raspberry-pi-power-cat-feeder- updates/) Then I added a server instance and an iOS app so I could schedule / manually control feedings remotely. Great for short trips.

</comment><comment><USER48> I used a Rapsberry Pi (and a lot of Dynamixel servos, LiPo, gyro, etc) to build a small hexapod robot. I was mostly interested in learning about legged locomotion, and got a bit carried away. Using a normal-ish Linux platform with GPIO and USB devices made it really easy (and fun) to hack everything together.

[https://github.com/adammck/hexapod](https://github.com/adammck/hexapod)

<comment><USER49> I think you were featured on HN front page few times already :-)

</comment></comment><comment><USER50> We use one in the office to monitor the Jenkins build status of our dev branch. [https://github.com/SeanCline/build- indicator/](https://github.com/SeanCline/build-indicator/)

Hardware-wise, it's just a Pi and UnicornHat. I wanted to use off-the-shelf components since it's in an office environment with rather strict rules about what can be plugged into the wall.

</comment><comment><USER51> A friend and I put together a free dynamic DNS service [1] offering cool custom domains aimed at the Raspberry Pi community (and similar hardware hackers.)

It's not strictly a hardware project, but it's a crucial building block for any network-enabled Raspberry Pi project, and we'd love your feedback.

[1]: [https://www.legitdns.com](https://www.legitdns.com)

<comment><AUTHOR> Awesome!

</comment></comment><comment><USER52> i used raspberry pi 2 in order to build 2d mapping robot(i installed ROS on top of ubuntu on pi2). i also tried to make it autonomus but lack of some hardware such as motor encoder made it quite hard to accomplish so i did not go for it. See snippets of video diary at [https://robot.birkankolcu.com](https://robot.birkankolcu.com)

<comment><USER53> That looks really cool. Have you got any documentation for implementing it?

</comment></comment><comment><USER54> I built a voice-activated light switch using Pi. Demo and schematics here: [http://arunpn.com/projects/voice-activated-light- switch/](http://arunpn.com/projects/voice-activated-light-switch/) After that project, I have slowly added more functionality to it like controlling music, alarms, etc.

</comment><comment><USER55> I've a few simple projects around the house

1\. I've a python script that sends bluetooth LE commands to my ceiling fan & lights. Ceiling fan has got a bluetooth LE remote you get from Lowes. Then used ha-bridge to simulate Philips hue, so now I can control the lights & fan using Alexa.

Built it to turn lights no/off with my new born daughter in hand.

And since about 5 months of age, every time anyone says the word Alexa she looks around to see the change in environment.

2\. Run this useful open source project called LittleSleeper[1] to detect my baby daughter crying at night.

3\. Configured IP camera to upload pictures on activity and use BerryNet[2] to detect whats in the images

[1]: [https://github.com/NeilYager/LittleSleeper](https://github.com/NeilYager/LittleSleeper) [2]: [https://github.com/DT42/BerryNet](https://github.com/DT42/BerryNet)

<comment><USER17> Cool ! If you want more privacy around your kid than streaming what she is saying to Amazon with Alexa, you can use the platform we are building at [https://snips.ai](https://snips.ai), it is free and will be open-source too!

<comment><USER55> Thanks, I'll try this out!

</comment></comment></comment><comment><USER56> Created a temperature sensor system that can generate alerts whenever temperature or humidity goes above or below a limit configured by the admin portal. Along with Elasticsearch and Kibana graphs can be generated and also data can be seen on top of the floor plan to understand hot and cold spots in a building.

The repository below contains code and instructions on how to setup the Raspberry Pi device to report temperature/humidity data along with manual alerts to the server: [https://github.com/ankurp/thermostat- sensor](https://github.com/ankurp/thermostat-sensor)

The server code where data is received and saved, notifications are sent, and the entire system configured via the admin portal is here: [https://github.com/ankurp/thermostat](https://github.com/ankurp/thermostat)

</comment><comment><USER57> I've got more plans than finished projects. One is an attempt to build a GPIO- connected synthesizer using an old OPL-3 chip and the DAC chips that are designed to be paired with it. The plan would be to add direct hardware output to Adplug and Dosbox.

Another is a quadrupedal robot (more like a puppet to start with; autonomy would come after I've got the gait control code working). Control would be through a bluetooth game controller. I've got a laser-cut acrylic body for the thing and a servo control hat to deal with timing jitter.

Third, I've got a Pi-Zero and a broken PSP. 4.3" Backup camera screens are the right size, shape, and resolution to fit in the PSP case, they can be modified to take 5V instead of 12, and the Pi-Zero has 2 contact pins for the analog video out. I'd need to experiment with audio out; I've got a couple ideas.

</comment><comment><USER58> These little computers are floppy and like to slide off the desk under the weight of their own USB cables. This has led me into many adventures with wall mounted enclosures.

[0] [https://github.com/cjdaly/CompuCanvas](https://github.com/cjdaly/CompuCanvas)

</comment><comment><USER59> I built a smart scale that keeps track of my cat's food intake, compute trends, and text me when has been too long since eating:

[https://github.com/rodrigosetti/smart-pet-food- tracker](https://github.com/rodrigosetti/smart-pet-food-tracker)

</comment><comment><USER60> ChronoPill is a DIY Time Capsule alternative for Raspberry Pi. I used Resin to make it ultra reproducible. MacOSX can backup to this networked drive just fine.

[https://github.com/amingilani/chronopill](https://github.com/amingilani/chronopill)

</comment><comment><USER16> Also made a replay camera for the office foosball table. We have an iPad scorekeeping application that queries the Pi for a video replay after every goal.

[https://github.com/johnboiles/replaycam](https://github.com/johnboiles/replaycam)

</comment><comment><USER61> Is anyone using this to sense water levels (or just the presence of water)? I'd like to implement a doohickey that monitors water levels in a water storage tank which is not easily accessible. So it must be very reliable, and install-and-forget, as access is a pain in the ass.

<comment><USER62> I am going to try that this next week. I live in a third world country, and here most days there's no water coming from the pipes.

So I am going to try and monitor the water levels in my house.

What I bought to do that: A ESP8266 board (it's like an WiFi arduino), and an ultrasound distance sensor.

My plan is to point the sensor vertically towards the water. It emits sound and then measures the time it takes for that sound to bounce back. I _think_ I can use to measure the level of water.

Then the results will be sent (using MQTT) to my Raspberry Pi that is running Home Assistant.

<comment><USER61> Are you concerned about condensation on the ultrasound detector throwing off your readings?

</comment></comment></comment><comment><USER16> Also also, I have a Pi with a usb RTL-SDR radio receiver functioning as a mobile HAM APRS iGate: [https://github.com/johnboiles/pi-rtlsdr-igate- docker](https://github.com/johnboiles/pi-rtlsdr-igate-docker)

</comment><comment><USER63> An R-Pi3 configured as a special router / credit-meter which has kids earn their internet access by completing online activities. [https://netdispenser.github.io/](https://netdispenser.github.io/)

</comment><comment><USER64> I have three Pis currently "deployed":

1) Internet radio w/ an amplifier in a cigar box. It was a gift for my gf and only plays the station she listened to in college. [https://github.com/rocktronica/curpi](https://github.com/rocktronica/curpi)

2) Timed camera and GIF maker for my cat feeder. [https://github.com/rocktronica/feedergif](https://github.com/rocktronica/feedergif)

3) OctoPrint server for my 3D printer [http://octoprint.org/](http://octoprint.org/)

[edit: formatting]

</comment><comment><USER65> I have one running PiAware: [http://flightaware.com/adsb/piaware/](http://flightaware.com/adsb/piaware/)

I built a "Kitchen Dashboard" last year: [https://gavinr.com/2016/01/10/raspberry-pi-kitchen- dashboard...](https://gavinr.com/2016/01/10/raspberry-pi-kitchen-dashboard/)

And of course you have to build a RetroPie: [https://retropie.org.uk/](https://retropie.org.uk/)

<comment><USER66> +1 for PiAware. It's just about the easiest project and a good intro to the Pi.

Other things on Pi in my house: OpenVPN server ([http://www.pivpn.io/](http://www.pivpn.io/)) and Node-RED ([https://nodered.org/](https://nodered.org/)) for collecting temperature data and pushing to Power BI.

</comment></comment><comment><USER67> I've used it to run a family dashboard: [https://github.com/danesparza/Dashboard](https://github.com/danesparza/Dashboard)

I use Octopi to control my 3d printer: [https://octopi.octoprint.org/](https://octopi.octoprint.org/)

And I've started experimenting with different sensors using Golang and embd: [https://github.com/kidoman/embd](https://github.com/kidoman/embd)

</comment><comment><USER68> I have my Pi hooked up to an LED strip in my room. It is running a flask server so I can control the light with a website or with my Alexa. I use it everyday and it was super easy to set up.

</comment><comment><USER69> Made a smart foosball table last summer! [https://www.youtube.com/watch?v=QSY4FEy9ZuY](https://www.youtube.com/watch?v=QSY4FEy9ZuY)

</comment><comment><USER70> I use it to turn my television on and off: [https://github.com/simonbyrne/fauxmo](https://github.com/simonbyrne/fauxmo)

</comment><comment><USER71> I'm working on an open source Canary clone with a RasPi Zero W and Camera module, a couple of sensors (Smoke and CO) and MotionEye software all stuffed into a Pringles can. :)

</comment><comment><USER72> At our office we're big tea drinkers with a massive Teapot from Ikea so with a set of USB scales, we turned one into an internet connected Teapot complete with leaderboard, it's gamified tea making for the office.

[https://github.com/gbrady92/Teabot](https://github.com/gbrady92/Teabot)

Leaderboard - [http://www.teabot.co.uk/index.html](http://www.teabot.co.uk/index.html)

</comment><comment><USER73> Waaay back in 2011, when I was getting started with electronics, I combined a Raspberry Pi 2 with a battery pack and a head mounted display for an iPod Video to make a HUD. It was horribly hacky, but I did manage to get it to show the time and my Google Calendar events with a Python GUI program and Internet over Bluetooth to my phone.

Some pictures: [https://github.com/Hylian/PiHUD](https://github.com/Hylian/PiHUD)

</comment><comment><USER74> Not myself, but a friend:

Making an snes emulator in an HDMI dongle form factor with wireless controllers.

SNES on your main TV system, switch TV inputs, play Super Mario Kart. No hookups, no wires.

</comment><comment><USER75> a post on hackaday.com led me to a lightning sensor breakout board that connects at 3.3V which is perfect for a rpi. since I live in florida I jumped at it. just got it hooked up the other day, unfortunately NOAA's lightning strike database is a few days behind so in a day or two I'll be able to check the accuracy of it. it's my first electronics project with the rpi and I have definitely learned a lot already

<comment><USER76> Nice! I've been trying to do this but I haven't been able to find a lightning sensor breakout board that doesn't cost an arm and a leg. Can you link me to the one you purchased?

<comment><USER75> [http://www.embeddedadventures.com/as3935_lightning_sensor_mo...](http://www.embeddedadventures.com/as3935_lightning_sensor_module_mod-1016.html) that's the breakout, this is the python library you can use with it: [https://github.com/pcfens/RaspberryPi- AS3935/](https://github.com/pcfens/RaspberryPi-AS3935/)

</comment></comment></comment><comment><USER77> I hacked a remote controlled car and connected it to the Twitch chat so it can be controlled through chat commands.

It can also stream the video back to my computer so people on the stream can see where the car is going.

[https://fullstack.network/i-built-a-car-that-is-being- contro...](https://fullstack.network/i-built-a-car-that-is-being-controlled- by-the-twitch-chat-heres-how-25e9f02c42ab)

</comment><comment><USER78> Currently I am building a mobile GPS beacon which a drone can follow. The goal is to create a small follow-me box without the need for a smartphone.

</comment><comment><USER79> We've built a doorlock system with Raspi, note here: [https://code.oursky.com/iot-side-project-chima-open- door/](https://code.oursky.com/iot-side-project-chima-open-door/) and code here: [https://github.com/oursky/doorlock](https://github.com/oursky/doorlock)

</comment><comment><USER19> Kilgore. A robot trout! [https://www.youtube.com/watch?v=7busGsuIOU4](https://www.youtube.com/watch?v=7busGsuIOU4)

Fish code is python: [https://github.com/djmips/trout](https://github.com/djmips/trout)

</comment><comment><USER80> I've built a drone that can be controlled by rpi. Phase 1 is completed : [http://akhilspassion.blogspot.co.id/2017/07/building- autonom...](http://akhilspassion.blogspot.co.id/2017/07/building-autonomous- drone-with.html?m=1)

</comment><comment><USER38> I put retropie on one, then added a Picade hat to easily connect some real arcade buttons and joystick to play mame games on. I put it inside of an old restored Defender cabinet.

I'm also in the process of building a "magic mirror" which will have some home automation and Google assistant built in.

</comment><comment><USER81> I made an ugly multi-coloured light controlled by a companion app - [https://tomjwatson.com/blog/raspberry-pi-powered-home- lighti...](https://tomjwatson.com/blog/raspberry-pi-powered-home-lighting)

</comment><comment><USER82> Raspberry Pi Nintendo cartridge [http://www.dontwatchme.com/build-raspberry- pi-retropie-ninte...](http://www.dontwatchme.com/build-raspberry-pi-retropie- nintendo-cartridge)

</comment><comment><USER83> [http://joustmania.com](http://joustmania.com) Open source 16 player version of JS Joust, all running on a pi, very easy setup, and tons of features and game modes

</comment><comment><USER84> It acts as a great DHCP and DNS server. It translates short addresses/hostnames into IP address, which is great for commands like "ssh pi@hub". Also it's much faster than my router.

</comment><comment><USER85> I will be using the EnviroPhat from Pimoroni to collect data about the solar eclipse on August 21. I was more motivated by the data than putting together my own hardware for this one.

</comment><comment><USER86> Just finished setting up openVPN on a RPi3b so my salesperson and I can access the CRM from outside my network.

</comment><comment><USER87> HomeKit Hub & coupled with an ESP8266(Or even without it) you can make Siri do practically anything.

</comment><comment><USER88> I use it as a GopiGo, Timelapse camera which i mount on my car dashboard to record my road trips.

</comment><comment><USER89> Emulation (RetroPie), VPN (PiVPN), DNS (PiHole) and IP Camera (MotionEye OS)

</comment><comment><USER90> I made a surveillance camera for my new home, it actually works quite well.

</comment><comment><USER91> block all ads on your network: [https://pi-hole.net/](https://pi-hole.net/)</comment>


Khan Academy now accepts Bitcoin via Coinbase - <AUTHOR> http://blog.coinbase.com/post/57119163938/khan-academy-now-accepts-bitcoin-donations-using <comment><USER2> Tangentially related Matt from Wordpress did an AMA on reddit yesterday and mentioned the Bitcoin integration they've done: in the last 9 months there's been 94 total Bitcoin transactions. Hopefully Khan academy will release figures too so we can see how the adoption of Bitcoin is going. [http://www.reddit.com/r/IAmA/comments/1jg781/i_am_matt_mulle...](http://www.reddit.com/r/IAmA/comments/1jg781/i_am_matt_mullenweg_cofounder_of_wordpress_18_of/cbeev5a)

<comment><USER3> Since I turned this on at 6pm today, there's been 24 transactions for a total of 6.174 BTC.

There's been 4 donations of 1.0 BTC but none larger. I set the default at 1.0 BTC; perhaps I should increase it!

<comment><USER4> Don't get greedy.

</comment></comment></comment><comment><USER5> Cool stuff, but I wonder, even if the price of BTC stabilizes, will "normal everyday people" use it?

I'm taking a coursera class (Startup 101 by Stanford) where we'll use BTC to fund our projects. But it seems like it's more confusing to the average user to see a "Donate Bitcoin" button on my page. I'd rather it just say "Donate" and have my payments processor accept any local currency.

Also, the Winklevoss twins are BTC speculators.

[http://blogs.wsj.com/moneybeat/2013/07/02/beware-the- risks-o...](http://blogs.wsj.com/moneybeat/2013/07/02/beware-the-risks-of-the- bitcoin-winklevii-outline-the-downside/)

<comment><USER6> > I'd rather it just say "Donate" and have my payments processor accept any > local currency.

They have dealt with the ecentricities of their local money their entire life. Bitcoin is new. In the end, from an objective standpoint, scanning a QR code and confirming the transaction is easier than dealing with debit / credit cards -> bank accounts -> checkbooks, etc. I still have a POS time with routing numbers and bank account numbers and those are effectively fiat bitcoin addresses.

Bitcoin is so much easier to use because all you need to use it is a bitcoin address.

<comment><USER7> But to obtain BitCoin in the first place, you need to trust Coinbase with your account and routing number and possibly ID documents, wait a week for your BitCoin to become available, and _then_ spend it.

To my knowledge there is no way for a first-time BitCoin user to make a purchase right away.

<comment><USER6> Coinbase delays the disbursement to keep you from chargebacking. Same thing happens in Dwolla. If you send a money order over snail mail to an exchange, you can get your funds available same day (they receive it).

It isn't anything bitcoin _can_ change - it is moving money from a chargeback system to one without a way to reverse transactions. If they allowed chargebacking, they would be exploited and go bankrupt.</comment></comment></comment></comment>