Tag Archives: Bits

This IoT Pet Monitor barks back

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/iot-pet-monitor/

Jennifer Fox, founder of FoxBot Industries, uses a Raspberry Pi pet monitor to check the sound levels of her home while she is out, allowing her to keep track of when her dog Marley gets noisy or agitated, and to interact with the gorgeous furball accordingly.

Bark Back Project Demo

A quick overview and demo of the Bark Back, a project to monitor and interact with Check out the full tutorial here: https://learn.sparkfun.com/tutorials/bark-back-interactive-pet-monitor For any licensing requests please contact [email protected]

Marley, bark!

Using a Raspberry Pi 3, speakers, SparkFun’s MEMS microphone breakout board, and an analogue-to-digital converter (ADC), the IoT Pet Monitor is fairly easy to recreate, all thanks to Jennifer’s full tutorial on the FoxBot website.

Building the pet monitor

In a nutshell, once the Raspberry Pi and the appropriate bits and pieces are set up, you’ll need to sign up at CloudMQTT — it’s free if you select the Cute Cat account. CloudMQTT will create an invisible bridge between your home and wherever you are that isn’t home, so that you can check in on your pet monitor.

Screenshot CloudMQTT account set-up — IoT Pet Monitor Bark Back Raspberry Pi

Image c/o FoxBot Industries

Within the project code, you’ll be able to calculate the peak-to-peak amplitude of sound the microphone picks up. Then you can decide how noisy is too noisy when it comes to the occasional whine and bark of your beloved pup.

MEMS microphone breakout board — IoT Pet Monitor Bark Back Raspberry Pi

The MEMS microphone breakout board collects sound data and relays it back to the Raspberry Pi via the ADC.
Image c/o FoxBot Industries

Next you can import sounds to a preset song list that will be played back when the volume rises above your predefined threshold. As Jennifer states in the tutorial, the sounds can easily be recorded via apps such as Garageband, or even on your mobile phone.

Using the pet monitor

Whenever the Bark Back IoT Pet Monitor is triggered to play back audio, this information is fed to the CloudMQTT service, allowing you to see if anything is going on back home.

A sitting dog with a doll in its mouth — IoT Pet Monitor Bark Back Raspberry Pi

*incoherent coos of affection from Alex*
Image c/o FoxBot Industries

And as Jennifer recommends, a update of the project could include a camera or sensors to feed back more information about your home environment.

If you’ve created something similar, be sure to let us know in the comments. And if you haven’t, but you’re now planning to build your own IoT pet monitor, be sure to let us know in the comments. And if you don’t have a pet but just want to say hi…that’s right, be sure to let us know in the comments.

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HackSpace magazine 4: the wearables issue

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-4-wearables/

Big things are afoot in the world of HackSpace magazine! This month we’re running our first special issue, with wearables projects throughout the magazine. Moreover, we’re giving away our first subscription gift free to all 12-month print subscribers. Lastly, and most importantly, we’ve made the cover EXTRA SHINY!

HackSpace magazine issue 4 cover

Prepare your eyeballs — it’s HackSpace magazine issue 4!

Wearables

In this issue, we’re taking an in-depth look at wearable tech. Not Fitbits or Apple Watches — we’re talking stuff you can make yourself, from projects that take a couple of hours to put together, to the huge, inspiring builds that are bringing technology to the runway. If you like wearing clothes and you like using your brain to make things better, then you’ll love this feature.

We’re continuing our obsession with Nixie tubes, with the brilliant Time-To-Go-Clock – Trump edition. This ingenious bit of kit uses obsolete Russian electronics to count down the time until the end of the 45th president’s term in office. However, you can also program it to tell the time left to any predictable event, such as the deadline for your tax return or essay submission, or the date England gets knocked out of the World Cup.

HackSpace magazine page 08
HackSpace magazine page 70
HackSpace magazine issue 4 page 98

We’re also talking to Dr Lucy Rogers — NASA alumna, Robot Wars judge, and fellow of the Institution of Mechanical Engineers — about the difference between making as a hobby and as a job, and about why we need the Guild of Makers. Plus, issue 4 has a teeny boat, the most beautiful Raspberry Pi cases you’ve ever seen, and it explores the results of what happens when you put a bunch of hardware hackers together in a French chateau — sacré bleu!

Tutorials

As always, we’ve got more how-tos than you can shake a soldering iron at. Fittingly for the current climate here in the UK, there’s a hot water monitor, which shows you how long you have before your morning shower turns cold, and an Internet of Tea project to summon a cuppa from your kettle via the web. Perhaps not so fittingly, there’s also an ESP8266 project for monitoring a solar power station online. Readers in the southern hemisphere, we’ll leave that one for you — we haven’t seen the sun here for months!

And there’s more!

We’re super happy to say that all our 12-month print subscribers have been sent an Adafruit Circuit Playground Express with this new issue:

Adafruit Circuit Playground Express HackSpace

This gadget was developed primarily with wearables in mind and comes with all sorts of in-built functionality, so subscribers can get cracking with their latest wearable project today! If you’re not a 12-month print subscriber, you’ll miss out, so subscribe here to get your magazine and your device,  and let us know what you’ll make.

The post HackSpace magazine 4: the wearables issue appeared first on Raspberry Pi.

BootStomp – Find Android Bootloader Vulnerabilities

Post Syndicated from Darknet original https://www.darknet.org.uk/2018/02/bootstomp-find-android-bootloader-vulnerabilities/?utm_source=rss&utm_medium=social&utm_campaign=darknetfeed

BootStomp – Find Android Bootloader Vulnerabilities

BootStomp is a Python-based tool, with Docker support that helps you find two different classes of Android bootloader vulnerabilities and bugs. It looks for memory corruption and state storage vulnerabilities.

Note that BootStomp works with boot-loaders compiled for ARM architectures (32 and 64 bits both) and that results might slightly vary depending on angr and Z3’s versions. This is because of the time angr takes to analyze basic blocks and to Z3’s expression concretization results.

Read the rest of BootStomp – Find Android Bootloader Vulnerabilities now! Only available at Darknet.

Cloudflare Hit With Piracy Lawsuit After Abuse Form ‘Fails’

Post Syndicated from Ernesto original https://torrentfreak.com/cloudflare-hit-with-piracy-lawsuit-after-abuse-form-fails-180210/

Seattle-based artist Christopher Boffoli is no stranger when it comes to suing tech companies for aiding copyright infringement of his work.

Boffoli has filed lawsuits against Imgur, Twitter, Pinterest, Google, and others, which were dismissed and/or settled out of court under undisclosed terms.

This month he filed a new case against another intermediary, Cloudflare, which has had its fair share of piracy allegations in recent years.

In common with other companies, Cloudflare is accused of contributing to copyright infringements of Boffoli’s “Big Appetites” miniatures series. In this case, several Cloudflare customers allegedly posted these photos on their sites which were then reproduced on the servers of the CDN provider.

The lawsuit mentions that the infringing copies were posted on unique-landscape.com and baklol.com. This was also pointed out to Cloudflare by Boffoli, who sent the company DMCA takedown notices in October and November of last year.

While the photographer received an automated response, the photos in question remained online. Through the lawsuit, Boffoli hopes this will change.

“CloudFlare induced, caused, or materially contributed to the Infringing Websites’ publication,” the complaint reads. “CloudFlare had actual knowledge of the Infringing Content. Boffoli provided notice to CloudFlare in compliance with the DMCA, and CloudFlare failed to disable access to or remove the Infringing Websites.”

The photographer is asking the court to order an injunction preventing Cloudflare from making his work available. In addition, the complaint asks for actual and statutory damages for willful copyright infringement. With at least four photos in the lawsuit, the potential damages are more than half a million dollars.

While it’s not mentioned in the complaint, the email communication between Boffoli and Cloudflare goes further than just an automated response. Court records show that the photographer initially didn’t ask Cloudflare to remove the infringing photos. Instead, he asked the CDN provider to forward them to the ISP or site owner.

“I would be grateful if you would forward this DMCA takedown request to the website owner and ISP so these infringing links can immediately be removed,” it read.

Part of the email communication

From then on things escalated a bit. The emails reveal that Boffoli had trouble reporting the infringing photos through the required form.

When the photographer pointed this out in a direct email, Cloudflare urged him to try the form again as that was the only way to send the DMCA request to the designated copyright agent.

“The DMCA doesn’t require us to process reports not sent to our registered agent as per our registration with the US Copyright Office. Our registered copyright agent is the form located at cloudflare.com/abuse/form and you may proceed via that avenue,” Cloudflare wrote.

If the case moves forward, Cloudflare may use this to argue that it never received a proper DMCA takedown notice. However, Boffoli wasn’t planning on trying again and instead threatened a lawsuit, unless Cloudflare took immediate action.

“As I have said, your form did not work for me despite repeated attempts to use it. And it is insulting for you to suggest that it’s working fine when it is not. So again, this is absolutely my last attempt to get you to respond to this infringement for which you are impeding the removal,” Boffoli wrote.

“If you take no action now I will forward this to my legal team this week. It is more than enough of a burden to have to waste countless hours policing my own copyrights without organizations like Cloudflare running interference for copyright infringers. I am not averse to asking a federal judge to compel you to deal with these copyright infringements. And I will seek statutory damages for contributory infringement at that time.”

As it turns out, that was not an idle threat.

—-

A copy of the complaint is available here (pdf) and the email exhibits can be found here (pdf).

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Backblaze Hard Drive Stats for 2017

Post Syndicated from Andy Klein original https://www.backblaze.com/blog/hard-drive-stats-for-2017/

Backbalze Drive Stats 2017 Review

Beginning in April 2013, Backblaze has recorded and saved daily hard drive statistics from the drives in our data centers. Each entry consists of the date, manufacturer, model, serial number, status (operational or failed), and all of the SMART attributes reported by that drive. As of the end of 2017, there are about 88 million entries totaling 23 GB of data. You can download this data from our website if you want to do your own research, but for starters here’s what we found.

Overview

At the end of 2017 we had 93,240 spinning hard drives. Of that number, there were 1,935 boot drives and 91,305 data drives. This post looks at the hard drive statistics of the data drives we monitor. We’ll review the stats for Q4 2017, all of 2017, and the lifetime statistics for all of the drives Backblaze has used in our cloud storage data centers since we started keeping track. Along the way we’ll share observations and insights on the data presented and we look forward to you doing the same in the comments.

Hard Drive Reliability Statistics for Q4 2017

At the end of Q4 2017 Backblaze was monitoring 91,305 hard drives used to store data. For our evaluation we remove from consideration those drives which were used for testing purposes and those drive models for which we did not have at least 45 drives (read why after the chart). This leaves us with 91,243 hard drives. The table below is for the period of Q4 2017.

Hard Drive Annualized Failure Rates for Q4 2017

A few things to remember when viewing this chart:

  • The failure rate listed is for just Q4 2017. If a drive model has a failure rate of 0%, it means there were no drive failures of that model during Q4 2017.
  • There were 62 drives (91,305 minus 91,243) that were not included in the list above because we did not have at least 45 of a given drive model. The most common reason we would have fewer than 45 drives of one model is that we needed to replace a failed drive and we had to purchase a different model as a replacement because the original model was no longer available. We use 45 drives of the same model as the minimum number to qualify for reporting quarterly, yearly, and lifetime drive statistics.
  • Quarterly failure rates can be volatile, especially for models that have a small number of drives and/or a small number of drive days. For example, the Seagate 4 TB drive, model ST4000DM005, has a annualized failure rate of 29.08%, but that is based on only 1,255 drive days and 1 (one) drive failure.
  • AFR stands for Annualized Failure Rate, which is the projected failure rate for a year based on the data from this quarter only.

Bulking Up and Adding On Storage

Looking back over 2017, we not only added new drives, we “bulked up” by swapping out functional and smaller 2, 3, and 4TB drives with larger 8, 10, and 12TB drives. The changes in drive quantity by quarter are shown in the chart below:

Backblaze Drive Population by Drive Size

For 2017 we added 25,746 new drives, and lost 6,442 drives to retirement for a net of 19,304 drives. When you look at storage space, we added 230 petabytes and retired 19 petabytes, netting us an additional 211 petabytes of storage in our data center in 2017.

2017 Hard Drive Failure Stats

Below are the lifetime hard drive failure statistics for the hard drive models that were operational at the end of Q4 2017. As with the quarterly results above, we have removed any non-production drives and any models that had fewer than 45 drives.

Hard Drive Annualized Failure Rates

The chart above gives us the lifetime view of the various drive models in our data center. The Q4 2017 chart at the beginning of the post gives us a snapshot of the most recent quarter of the same models.

Let’s take a look at the same models over time, in our case over the past 3 years (2015 through 2017), by looking at the annual failure rates for each of those years.

Annual Hard Drive Failure Rates by Year

The failure rate for each year is calculated for just that year. In looking at the results the following observations can be made:

  • The failure rates for both of the 6 TB models, Seagate and WDC, have decreased over the years while the number of drives has stayed fairly consistent from year to year.
  • While it looks like the failure rates for the 3 TB WDC drives have also decreased, you’ll notice that we migrated out nearly 1,000 of these WDC drives in 2017. While the remaining 180 WDC 3 TB drives are performing very well, decreasing the data set that dramatically makes trend analysis suspect.
  • The Toshiba 5 TB model and the HGST 8 TB model had zero failures over the last year. That’s impressive, but with only 45 drives in use for each model, not statistically useful.
  • The HGST/Hitachi 4 TB models delivered sub 1.0% failure rates for each of the three years. Amazing.

A Few More Numbers

To save you countless hours of looking, we’ve culled through the data to uncover the following tidbits regarding our ever changing hard drive farm.

  • 116,833 — The number of hard drives for which we have data from April 2013 through the end of December 2017. Currently there are 91,305 drives (data drives) in operation. This means 25,528 drives have either failed or been removed from service due for some other reason — typically migration.
  • 29,844 — The number of hard drives that were installed in 2017. This includes new drives, migrations, and failure replacements.
  • 81.76 — The number of hard drives that were installed each day in 2017. This includes new drives, migrations, and failure replacements.
  • 95,638 — The number of drives installed since we started keeping records in April 2013 through the end of December 2017.
  • 55.41 — The average number of hard drives installed per day from April 2013 to the end of December 2017. The installations can be new drives, migration replacements, or failure replacements.
  • 1,508 — The number of hard drives that were replaced as failed in 2017.
  • 4.13 — The average number of hard drives that have failed each day in 2017.
  • 6,795 — The number of hard drives that have failed from April 2013 until the end of December 2017.
  • 3.94 — The average number of hard drives that have failed each day from April 2013 until the end of December 2017.

Can’t Get Enough Hard Drive Stats?

We’ll be presenting the webinar “Backblaze Hard Drive Stats for 2017” on Thursday February 9, 2017 at 10:00 Pacific time. The webinar will dig deeper into the quarterly, yearly, and lifetime hard drive stats and include the annual and lifetime stats by drive size and manufacturer. You will need to subscribe to the Backblaze BrightTALK channel to view the webinar. Sign up today.

As a reminder, the complete data set used to create the information used in this review is available on our Hard Drive Test Data page. You can download and use this data for free for your own purpose. All we ask are three things: 1) you cite Backblaze as the source if you use the data, 2) you accept that you are solely responsible for how you use the data, and 3) you do not sell this data to anyone — it is free.

Good luck and let us know if you find anything interesting.

The post Backblaze Hard Drive Stats for 2017 appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Pirate Bay Founder’s Domain Service “Mocks” NY Times Legal Threats

Post Syndicated from Ernesto original https://torrentfreak.com/pirate-bay-founders-domain-service-mocks-ny-times-legal-threats-180125/

Back in the day, The Pirate Bay was famous for its amusing responses to legal threats. Instead of complying with takedown notices, it sent witty responses to embarrass the senders.

Today the notorious torrent site gives copyright holders the silent treatment, but the good-old Pirate Bay spirit still lives on elsewhere.

Earlier today the anonymous domain registration service Njalla, which happens to be a venture of TPB co-founder Peter Sunde, posted a series of noteworthy responses it sent to The New York Times’ (NYT) legal department.

The newspaper warned the registration service about one of its customers, paywallnews.com, which offers the news service’s content without permission. Since this is a violation of The Times’ copyrights, according to the paper, Njalla should take action or face legal consequences.

NYT: Accordingly, we hereby demand that you immediately provide us with contact information — including email addresses — for both the actual owner of the paywallnew.com website, and for the hosting provider on which the paywallnew.com website is located.

If we have not heard from you within three (3) business days of receipt of this letter, we will have no choice but to pursue all available legal remedies.

Njalla is no stranger to threats of this kind but were somewhat offended by the harsh language, it seems. The company, therefore, decided to inform the NYT that there are more friendly ways to reach out.

Njalla: Thanks for that lovely e-mail. It’s always good to communicate with people that in their first e-mail use words as “we demand”, “pursue all available legal remedies” and so forth. I’d like to start out with some free (as in no cost) advice: please update your boiler threat letters to actually try what most people try first: being nice. It’s not expensive (actually the opposite) and actually it works much better than your method (source: a few tens of thousands years of human development that would not have been as efficient with threats as it would have been with cooperation).

In addition, Njalla also included a request of its own. They kindly asked (no demand) the newspaper’s legal department for proof that they are who they say they are. You can never be too cautious, after all.

Njalla: Now, back to the questions you sent us. We’re not sure who you are, so in order to move further we’d like to see a copy of your ID card, as well as a notarised power of attorney showing that you are actually representing the people you’re claiming to do.

This had the desired effect, for Njalla at least. The NYT replied with an apology for the tough language that was used, noting that they usually deal with companies that employ people who are used to reading legal documents.

The newspaper did, however, submit a notarized letter signed by the company’s Executive Vice President, General Counsel and Secretary, and once again asked for details on the Njalla customer.

NYT: Once again, as I mention above, the referenced website is stealing large amounts of New York Times content. If you click on this link: http://www.paywallnews.com/sites/nytimes

As this abuse — aside from being an egregious infringement of The Times’s copyright — breaches your own Terms of Service, I hope you will be able to see your way to helping me to put a stop to this practice by providing me with the name and contact information for the owner of paywallnews.com and for the ISP on which it is hosted.

This is when things started to get really interesting. Founded by someone with an extensive background in “sharing,” Njalla clearly has a different definition of stealing than the NYT’s legal department.

The reply, which is worth reading in full along with the rest of the communication, makes this quite clear.

Njalla: Stealing content seem quite harsh of this website though, didn’t know that they did that! Is there anyway you can get the stolen items back though? You should either go to the police and request them to help you get the stolen items back. Or maybe talk to your insurance company, they might help to compensate you for the loss. But a helpful idea; if they’ve stolen something and then put copies of that on a website that you can freely access, I would suggest just copying it, so that both of you have the same things. That’s a great thing with the digital world, everyone can have copies of things. I am surprised they stole something when they could just have copied it. I’m guessing it’s some older individuals that don’t know the possibilities of modern day technology to make copies.

It’s obvious that the domain registration service makes a clear distinction between copying and stealing.

Piracy vs. Theft

In addition, Njalla contests that the site is problematic at all, noting that this might be a “cultural difference.”

Njalla spotted something even more worrying though. The NYT claims that the site in question violates its terms of service. Specifically, they reference the section that prohibits sites from spreading content that is illegal according to local law.

Is the NYT perhaps spreading illegal content itself, Njalla questions?

Njalla: Deborah, I was quite shocked and appalled that you referred to this part of our ToS. It made me actually not visit the website in question even though you’ve linked it now a few times. You’re admitting to spreading illegal content at your newspaper, for profit, is that correct?

We’re quite big proponents of freedom of speech, let me assure you of that, but we also have limits. If you spread illegal content, and our customers stole that illegal content and are now handing out free copies of that, that’s a huge issue for us. Since it would be illegal for us to get those copies if they’re illegal, I’m asking you what type of content it is?

As an attachment to the reply, Njalla also sent back a “notarized” letter of their own, by simply copying the NYT letter and sticking their own logo on it, to show how easily these can be fabricated.

TorrentFreak reached out to Sunde who informed us that they never heard from The New York Times after the last reply. As a domain registrant, Njalla is not obliged to comply with takedown requests, he explains.

“If they need help from us on copyright issues, they’re totally missing what we’re doing, and that they should look somewhere else anyhow. But I think most domain services gets tons of these threat emails, and a lot of them think they’re responsible because they don’t have access to legal help and just shut customers down.

“That’s what a lot of our customers say at least, since they migrated from a shitty service which doesn’t know their own business,” Sunde adds.

The NYT is not completely without options though. If they take the case to court in Sweden and win an injunction against paywallnews.com, Njalla will comply. The same is true if a customer really violates the terms of service.

Meanwhile, paywallnews.com remains online.

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

HackSpace magazine 3: Scrap Heap Hacking

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-3-scrap-heap-hacking/

We’re making with a purpose in issue 3 of HackSpace magazine. Not only are we discovering ways in which 3D printing is helping to save resources — and in some case lives — in the developing world, we’re also going all out with recycling. While others might be content with separating their glass and plastic waste, we’re going much, much further by making useful things out of discarded old bits of rubbish you can find at your local scrapyard.

Hackspaces

We’re going to Cheltenham Hackspace to learn how to make a leather belt, to Liverpool to discover the ways in which an open-source design and some bits and bobs from IKEA are protecting our food supply, and we also take a peek through the doors of Nottingham Hackspace.

Tutorials

The new issue also has the most tutorials you’ll have seen anywhere since…well, since HackSpace magazine issue 2! Guides to 3D-printing on fabric, Arduino programming, and ESP8266 hacking are all to be found in issue 3. Plus, we’ve come up with yet another way to pipe numbers from the internet into big, red, glowing boxes — it’s what LEDs were made for.



With the addition of racing drones, an angry reindeer, and an intelligent toaster, we think we’ve definitely put together an issue you’ll enjoy.

Get your copy

The physical copy of HackSpace magazine is available at all good UK newsagents today, and you can order it online from the Raspberry Pi Press store wherever you are based. Moreover, you can download the free PDF version from our website. And if you’ve read our first two issues and enjoyed what you’ve seen, be sure to subscribe!

Write for us

Are you working on a cool project? Do you want to share your skills with the world, inspire others, and maybe show off a little? HackSpace magazine wants your article! Send an outline of your piece to us, and we’ll get back to you about including it in a future issue.

The post HackSpace magazine 3: Scrap Heap Hacking appeared first on Raspberry Pi.

SUPER game night 3: GAMES MADE QUICK??? 2.0

Post Syndicated from Eevee original https://eev.ee/blog/2018/01/23/super-game-night-3-games-made-quick-2-0/

Game night continues with a smorgasbord of games from my recent game jam, GAMES MADE QUICK??? 2.0!

The idea was to make a game in only a week while watching AGDQ, as an alternative to doing absolutely nothing for a week while watching AGDQ. (I didn’t submit a game myself; I was chugging along on my Anise game, which isn’t finished yet.)

I can’t very well run a game jam and not play any of the games, so here’s some of them in no particular order! Enjoy!

These are impressions, not reviews. I try to avoid major/ending spoilers, but big plot points do tend to leave impressions.

Weather Quest, by timlmul

short · rpg · jan 2017 · (lin)/mac/win · free on itch · jam entry

Weather Quest is its author’s first shipped game, written completely from scratch (the only vendored code is a micro OO base). It’s very short, but as someone who has also written LÖVE games completely from scratch, I can attest that producing something this game-like in a week is a fucking miracle. Bravo!

For reference, a week into my first foray, I think I was probably still writing my own Tiled importer like an idiot.

Only Mac and Windows builds are on itch, but it’s a LÖVE game, so Linux folks can just grab a zip from GitHub and throw that at love.

FINAL SCORE: ⛅☔☀

Pancake Numbers Simulator, by AnorakThePrimordial

short · sim · jan 2017 · lin/mac/win · free on itch · jam entry

Given a stack of N pancakes (of all different sizes and in no particular order), the Nth pancake number is the most flips you could possibly need to sort the pancakes in order with the smallest on top. A “flip” is sticking a spatula under one of the pancakes and flipping the whole sub-stack over. There’s, ah, a video embedded on the game page with some visuals.

Anyway, this game lets you simulate sorting a stack via pancake flipping, which is surprisingly satisfying! I enjoy cleaning up little simulated messes, such as… incorrectly-sorted pancakes, I guess?

This probably doesn’t work too well as a simulator for solving the general problem — you’d have to find an optimal solution for every permutation of N pancakes to be sure you were right. But it’s a nice interactive illustration of the problem, and if you know the pancake number for your stack size of choice (which I wish the game told you — for seven pancakes, it’s 8), then trying to restore a stack in that many moves makes for a nice quick puzzle.

FINAL SCORE: \(\frac{18}{11}\)

Framed Animals, by chridd

short · metroidvania · jan 2017 · web/win · free on itch · jam entry

The concept here was to kill the frames, save the animals, which is a delightfully literal riff on a long-running AGDQ/SGDQ donation incentive — people vote with their dollars to decide whether Super Metroid speedrunners go out of their way to free the critters who show you how to walljump and shinespark. Super Metroid didn’t have a showing at this year’s AGDQ, and so we have this game instead.

It’s rough, but clever, and I got really into it pretty quickly — each animal you save gives you a new ability (in true Metroid style), and you get to test that ability out by playing as the animal, with only that ability and no others, to get yourself back to the most recent save point.

I did, tragically, manage to get myself stuck near what I think was about to be the end of the game, so some of the animals will remain framed forever. What an unsatisfying conclusion.

Gravity feels a little high given the size of the screen, and like most tile-less platformers, there’s not really any way to gauge how high or long your jump is before you leap. But I’m only even nitpicking because I think this is a great idea and I hope the author really does keep working on it.

FINAL SCORE: $136,596.69

Battle 4 Glory, by Storyteller Games

short · fighter · jan 2017 · win · free on itch · jam entry

This is a Smash Bros-style brawler, complete with the four players, the 2D play area in a 3D world, and the random stage obstacles showing up. I do like the Smash style, despite not otherwise being a fan of fighting games, so it’s nice to see another game chase that aesthetic.

Alas, that’s about as far as it got — which is pretty far for a week of work! I don’t know what more to say, though. The environments are neat, but unless I’m missing something, the only actions at your disposal are jumping and very weak melee attacks. I did have a good few minutes of fun fruitlessly mashing myself against the bumbling bots, as you can see.

FINAL SCORE: 300%

Icnaluferu Guild, Year Sixteen, by CHz

short · adventure · jan 2017 · web · free on itch · jam entry

Here we have the first of several games made with bitsy, a micro game making tool that basically only supports walking around, talking to people, and picking up items.

I tell you this because I think half of my appreciation for this game is in the ways it wriggled against those limits to emulate a Zelda-like dungeon crawler. Everything in here is totally fake, and you can’t really understand just how fake unless you’ve tried to make something complicated with bitsy.

It’s pretty good. The dialogue is entertaining (the rest of your party develops distinct personalities solely through oneliners, somehow), the riffs on standard dungeon fare are charming, and the Link’s Awakening-esque perspective walls around the edges of each room are fucking glorious.

FINAL SCORE: 2 bits

The Lonely Tapes, by JTHomeslice

short · rpg · jan 2017 · web · free on itch · jam entry

Another bitsy entry, this one sees you play as a Wal— sorry, a JogDawg, which has lost its cassette tapes and needs to go recover them!

(A cassette tape is like a VHS, but for music.)

(A VHS is—)

I have the sneaking suspicion that I missed out on some musical in-jokes, due to being uncultured swine. I still enjoyed the game — it’s always clear when someone is passionate about the thing they’re writing about, and I could tell I was awash in that aura even if some of it went over my head. You know you’ve done good if someone from way outside your sphere shows up and still has a good time.

FINAL SCORE: Nine… Inch Nails? They’re a band, right? God I don’t know write your own damn joke

Pirate Kitty-Quest, by TheKoolestKid

short · adventure · jan 2017 · win · free on itch · jam entry

I completely forgot I’d even given “my birthday” and “my cat” as mostly-joking jam themes until I stumbled upon this incredible gem. I don’t think — let me just check here and — yeah no this person doesn’t even follow me on Twitter. I have no idea who they are?

BUT THEY MADE A GAME ABOUT ANISE AS A PIRATE, LOOKING FOR TREASURE

PIRATE. ANISE

PIRATE ANISE!!!

This game wins the jam, hands down. 🏆

FINAL SCORE: Yarr, eight pieces o’ eight

CHIPS Mario, by NovaSquirrel

short · platformer · jan 2017 · (lin/mac)/win · free on itch · jam entry

You see this? This is fucking witchcraft.

This game is made with MegaZeux. MegaZeux games look like THIS. Text-mode, bound to a grid, with two colors per cell. That’s all you get.

Until now, apparently?? The game is a tech demo of “unbound” sprites, which can be drawn on top of the character grid without being aligned to it. And apparently have looser color restrictions.

The collision is a little glitchy, which isn’t surprising for a MegaZeux platformer; I had some fun interactions with platforms a couple times. But hey, goddamn, it’s free-moving Mario, in MegaZeux, what the hell.

(I’m looking at the most recently added games on DigitalMZX now, and I notice that not only is this game in the first slot, but NovaSquirrel’s MegaZeux entry for Strawberry Jam last February is still in the seventh slot. RIP, MegaZeux. I’m surprised a major feature like this was even added if the community has largely evaporated?)

FINAL SCORE: n/a, disqualified for being probably summoned from the depths of Hell

d!¢< pic, by 573 Games

short · story · jan 2017 · web · free on itch · jam entry

This is a short story about not sending dick pics. It’s very short, so I can’t say much without spoiling it, but: you are generally prompted to either text something reasonable, or send a dick pic. You should not send a dick pic.

It’s a fascinating artifact, not because of the work itself, but because it’s so terse that I genuinely can’t tell what the author was even going for. And this is the kind of subject where the author was, surely, going for something. Right? But was it genuinely intended to be educational, or was it tongue-in-cheek about how some dudes still don’t get it? Or is it side-eying the player who clicks the obviously wrong option just for kicks, which is the same reason people do it for real? Or is it commentary on how “send a dick pic” is a literal option for every response in a real conversation, too, and it’s not that hard to just not do it — unless you are one of the kinds of people who just feels a compulsion to try everything, anything, just because you can? Or is it just a quick Twine and I am way too deep in this? God, just play the thing, it’s shorter than this paragraph.

I’m also left wondering when it is appropriate to send a dick pic. Presumably there is a correct time? Hopefully the author will enter Strawberry Jam 2 to expound upon this.

FINAL SCORE: 3½” 😉

Marble maze, by Shtille

short · arcade · jan 2017 · win · free on itch · jam entry

Ah, hm. So this is a maze navigated by rolling a marble around. You use WASD to move the marble, and you can also turn the camera with the arrow keys.

The trouble is… the marble’s movement is always relative to the world, not the camera. That means if you turn the camera 30° and then try to move the marble, it’ll move at a 30° angle from your point of view.

That makes navigating a maze, er, difficult.

Camera-relative movement is the kind of thing I take so much for granted that I wouldn’t even think to do otherwise, and I think it’s valuable to look at surprising choices that violate fundamental conventions, so I’m trying to take this as a nudge out of my comfort zone. What could you design in an interesting way that used world-relative movement? Probably not the player, but maybe something else in the world, as long as you had strong landmarks? Hmm.

FINAL SCORE: ᘔ

Refactor: flight, by fluffy

short · arcade · jan 2017 · lin/mac/win · free on itch · jam entry

Refactor is a game album, which is rather a lot what it sounds like, and Flight is one of the tracks. Which makes this a single, I suppose.

It’s one of those games where you move down an oddly-shaped tunnel trying not to hit the walls, but with some cute twists. Coins and gems hop up from the bottom of the screen in time with the music, and collecting them gives you points. Hitting a wall costs you some points and kills your momentum, but I don’t think outright losing is possible, which is great for me!

Also, the monk cycles through several animal faces. I don’t know why, and it’s very good. One of those odd but memorable details that sits squarely on the intersection of abstract, mysterious, and a bit weird, and refuses to budge from that spot.

The music is great too? Really chill all around.

FINAL SCORE: 🎵🎵🎵🎵

The Adventures of Klyde

short · adventure · jan 2017 · web · free on itch · jam entry

Another bitsy game, this one starring a pig (humorously symbolized by a giant pig nose with ears) who must collect fruit and solve some puzzles.

This is charmingly nostalgic for me — it reminds me of some standard fare in engines like MegaZeux, where the obvious things to do when presented with tiles and pickups were to make mazes. I don’t mean that in a bad way; the maze is the fundamental environmental obstacle.

A couple places in here felt like invisible teleport mazes I had to brute-force, but I might have been missing a hint somewhere. I did make it through with only a little trouble, but alas — I stepped in a bad warp somewhere and got sent to the upper left corner of the starting screen, which is surrounded by walls. So Klyde’s new life is being trapped eternally in a nowhere space.

FINAL SCORE: 19/20 apples

And more

That was only a third of the games, and I don’t think even half of the ones I’ve played. I’ll have to do a second post covering the rest of them? Maybe a third?

Or maybe this is a ludicrous format for commenting on several dozen games and I should try to narrow it down to the ones that resonated the most for Strawberry Jam 2? Maybe??

“Where to Invade Next” Popular Among North Korean Pirates

Post Syndicated from Ernesto original https://torrentfreak.com/where-to-invade-next-popular-among-north-korean-pirates-180114/

Due to the public nature of BitTorrent transfers, it’s easy to see what a person behind a certain IP-address is downloading.

There are even entire sites dedicated to making this information public. This includes the ‘I Know What You Download‘ service we’ve covered in the past.

While the data are not complete or perfect, looking at the larger numbers provides some interesting insights. The site recently released its overview of the most downloaded titles in various categories per country, for example.

What stands out is that there’s a lot of overlap between countries that seem vastly different.

Game of Thrones is the most downloaded TV show in America, but also in Iran, Mongolia, Uruguay, and Zambia. Other popular TV-shows in 2017, such as The Flash, The Big Bang Theory, and The Walking Dead also appear in the top ten in all these countries.

On the movie side, a similar picture emerges. Titles such as Wonder Woman, The Fate of the Furious, and Logan appear in many of the top tens. In fact, browsing through the result for various countries there are surprisingly little outliers.

The movie Prityazhenie does well in Russia and in India, Dangal is among the most pirated titles, but most titles appear globally. Even in North Korea, where Internet access is extremely limited, Game of Thrones is listed as the most downloaded TV-show.

However, North Korea also shows some odd results, perhaps because there are only a few downloads per day on average.

Browsing through the most downloaded movies we see that there are a lot of kids’ movies in the top ten, with ‘Despicable Me’ as the top result, followed by ‘Moana’ and ‘Minions’. The Hobbit trilogy also made it into the top ten.

12 most pirated movies in North Korea (2017)

The most eye-catching result, however, is the Michael Moore documentary ‘Where to Invade Next.’ While the title may suggest something more malicious, in this travelogue Moore ‘invades’ countries around the world to see in what areas the US can improve itself.

It’s unclear why North Koreans are so interested in this progressive film. Perhaps they are trying to pick up a few tips as well. This could also explain why good old MacGyver is listed among the most downloaded TV-series.

The annual overview of ‘I Know What You Download’ is available here, for those who are interested in more country statistics.

Finally, we have to note that North Korean IP-ranges have been vulnerable to hijacks in the past so you’re never 100% sure who might be using them. It might be the Russians…

Image credit: KNCA

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Judge Issues Devastating Order Against BitTorrent Copyright Troll

Post Syndicated from Ernesto original https://torrentfreak.com/judge-issues-devastating-order-bittorrent-copyright-troll-180110/

In recent years, file-sharers around the world have been pressured to pay significant settlement fees, or face legal repercussions.

These so-called “copyright trolling” efforts have been a common occurrence in the United States since the turn of the last decade.

Increasingly, however, courts are growing weary of these cases. Many districts have turned into no-go zones for copyright trolls and the people behind Prenda law were arrested and are being prosecuted in a criminal case.

In the Western District of Washington, the tide also appears to have turned. After Venice PI, a copyright holder of the film “Once Upon a Time in Venice”, sued a man who later passed away, concerns were raised over the validity of the evidence.

Venice PI responded to the concerns with a declaration explaining its data gathering technique and assuring the Court that false positives are out of the question.

That testimony didn’t help much though, as a recently filed minute order shows this week. The order applies to a dozen cases and prohibits the company from reaching out to any defendants until further notice, as there are several alarming issues that have to be resolved first.

One of the problems is that Venice PI declared that it’s owned by a company named Lost Dog Productions, which in turn is owned by Voltage Productions. Interestingly, these companies don’t appear in the usual records.

“A search of the California Secretary of State’s online database, however, reveals no registered entity with the name ‘Lost Dog’ or ‘Lost Dog Productions’,” the Court notes.

“Moreover, although ‘Voltage Pictures, LLC’ is registered with the California Secretary of State, and has the same address as Venice PI, LLC, the parent company named in plaintiff’s corporate disclosure form, ‘Voltage Productions, LLC,’ cannot be found in the California Secretary of State’s online database and does not appear to exist.”

In other words, the company that filed the lawsuit, as well as its parent company, are extremely questionable.

While the above is a reason for concern, it’s just the tip of the iceberg. The Court not only points out administrative errors, but it also has serious doubts about the evidence collection process. This was carried out by the German company MaverickEye, which used the tracking technology of another German company, GuardaLey.

GuardaLey CEO Benjamin Perino, who claims that he coded the tracking software, wrote a declaration explaining that the infringement detection system at issue “cannot yield a false positive.” However, the Court doubts this statement and Perino’s qualifications in general.

“Perino has been proffered as an expert, but his qualifications consist of a technical high school education and work experience unrelated to the peer-to-peer file-sharing technology known as BitTorrent,” the Court writes.

“Perino does not have the qualifications necessary to be considered an expert in the field in question, and his opinion that the surveillance program is incapable of error is both contrary to common sense and inconsistent with plaintiff’s counsel’s conduct in other matters in this district. Plaintiff has not submitted an adequate offer of proof”

It seems like the Court would prefer to see an assessment from a qualified independent expert instead of the person who wrote the software. For now, this means that the IP-address evidence, in these cases, is not good enough. That’s quite a blow for the copyright holder.

If that wasn’t enough the Court also highlights another issue that’s possibly even more problematic. When Venice PI requested the subpoenas to identify alleged pirates, they relied on declarations from Daniel Arheidt, a consultant for MaverickEye.

These declarations fail to mention, however, that MaverickEye has the proper paperwork to collect IP addresses.

“Nowhere in Arheidt’s declarations does he indicate that either he or MaverickEye is licensed in Washington to conduct private investigation work,” the order reads.

This is important, as doing private investigator work without a license is a gross misdemeanor in Washington. The copyright holder was aware of this requirement because it was brought up in related cases in the past.

“Plaintiff’s counsel has apparently been aware since October 2016, when he received a letter concerning LHF Productions, Inc. v. Collins, C16-1017 RSM, that Arheidt might be committing a crime by engaging in unlicensed surveillance of Washington citizens, but he did not disclose this fact to the Court.”

The order is very bad news for Venice PI. The company had hoped to score a few dozen easy settlements but the tables have now been turned. The Court instead asks the company to explain the deficiencies and provide additional details. In the meantime, the copyright holder is urged not to spend or transfer any of the settlement money that has been collected thus far.

The latter indicates that Venice PI might have to hand defendants their money back, which would be pretty unique.

The order suggests that the Judge is very suspicious of these trolling activities. In a footnote there’s a link to a Fight Copyright Trolls article which revealed that the same counsel dismissed several cases, allegedly to avoid having IP-address evidence scrutinized.

Even more bizarrely, in another footnote the Court also doubts if MaverickEye’s aforementioned consultant, Daniel Arheidt, actually exists.

“The Court has recently become aware that Arheidt is the latest in a series of German declarants (Darren M. Griffin, Daniel Macek, Daniel Susac, Tobias Fieser, Michael Patzer) who might be aliases or even fictitious.

“Plaintiff will not be permitted to rely on Arheidt’s declarations or underlying data without explaining to the Court’s satisfaction Arheidt’s relationship to the above-listed declarants and producing proof beyond a reasonable doubt of Arheidt’s existence,” the court adds.

These are serious allegations, to say the least.

If a copyright holder uses non-existent companies and questionable testimony from unqualified experts after obtaining evidence illegally to get a subpoena backed by a fictitious person….something’s not quite right.

A copy of the minute order, which affects a series of cases, is available here (pdf).

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Random with care

Post Syndicated from Eevee original https://eev.ee/blog/2018/01/02/random-with-care/

Hi! Here are a few loose thoughts about picking random numbers.

A word about crypto

DON’T ROLL YOUR OWN CRYPTO

This is all aimed at frivolous pursuits like video games. Hell, even video games where money is at stake should be deferring to someone who knows way more than I do. Otherwise you might find out that your deck shuffles in your poker game are woefully inadequate and some smartass is cheating you out of millions. (If your random number generator has fewer than 226 bits of state, it can’t even generate every possible shuffling of a deck of cards!)

Use the right distribution

Most languages have a random number primitive that spits out a number uniformly in the range [0, 1), and you can go pretty far with just that. But beware a few traps!

Random pitches

Say you want to pitch up a sound by a random amount, perhaps up to an octave. Your audio API probably has a way to do this that takes a pitch multiplier, where I say “probably” because that’s how the only audio API I’ve used works.

Easy peasy. If 1 is unchanged and 2 is pitched up by an octave, then all you need is rand() + 1. Right?

No! Pitch is exponential — within the same octave, the “gap” between C and C♯ is about half as big as the gap between B and the following C. If you pick a pitch multiplier uniformly, you’ll have a noticeable bias towards the higher pitches.

One octave corresponds to a doubling of pitch, so if you want to pick a random note, you want 2 ** rand().

Random directions

For two dimensions, you can just pick a random angle with rand() * TAU.

If you want a vector rather than an angle, or if you want a random direction in three dimensions, it’s a little trickier. You might be tempted to just pick a random point where each component is rand() * 2 - 1 (ranging from −1 to 1), but that’s not quite right. A direction is a point on the surface (or, equivalently, within the volume) of a sphere, and picking each component independently produces a point within the volume of a cube; the result will be a bias towards the corners of the cube, where there’s much more extra volume beyond the sphere.

No? Well, just trust me. I don’t know how to make a diagram for this.

Anyway, you could use the Pythagorean theorem a few times and make a huge mess of things, or it turns out there’s a really easy way that even works for two or four or any number of dimensions. You pick each coordinate from a Gaussian (normal) distribution, then normalize the resulting vector. In other words, using Python’s random module:

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def random_direction():
    x = random.gauss(0, 1)
    y = random.gauss(0, 1)
    z = random.gauss(0, 1)
    r = math.sqrt(x*x + y*y + z*z)
    return x/r, y/r, z/r

Why does this work? I have no idea!

Note that it is possible to get zero (or close to it) for every component, in which case the result is nonsense. You can re-roll all the components if necessary; just check that the magnitude (or its square) is less than some epsilon, which is equivalent to throwing away a tiny sphere at the center and shouldn’t affect the distribution.

Beware Gauss

Since I brought it up: the Gaussian distribution is a pretty nice one for choosing things in some range, where the middle is the common case and should appear more frequently.

That said, I never use it, because it has one annoying drawback: the Gaussian distribution has no minimum or maximum value, so you can’t really scale it down to the range you want. In theory, you might get any value out of it, with no limit on scale.

In practice, it’s astronomically rare to actually get such a value out. I did a hundred million trials just to see what would happen, and the largest value produced was 5.8.

But, still, I’d rather not knowingly put extremely rare corner cases in my code if I can at all avoid it. I could clamp the ends, but that would cause unnatural bunching at the endpoints. I could reroll if I got a value outside some desired range, but I prefer to avoid rerolling when I can, too; after all, it’s still (astronomically) possible to have to reroll for an indefinite amount of time. (Okay, it’s really not, since you’ll eventually hit the period of your PRNG. Still, though.) I don’t bend over backwards here — I did just say to reroll when picking a random direction, after all — but when there’s a nicer alternative I’ll gladly use it.

And lo, there is a nicer alternative! Enter the beta distribution. It always spits out a number in [0, 1], so you can easily swap it in for the standard normal function, but it takes two “shape” parameters α and β that alter its behavior fairly dramatically.

With α = β = 1, the beta distribution is uniform, i.e. no different from rand(). As α increases, the distribution skews towards the right, and as β increases, the distribution skews towards the left. If α = β, the whole thing is symmetric with a hump in the middle. The higher either one gets, the more extreme the hump (meaning that value is far more common than any other). With a little fiddling, you can get a number of interesting curves.

Screenshots don’t really do it justice, so here’s a little Wolfram widget that lets you play with α and β live:

Note that if α = 1, then 1 is a possible value; if β = 1, then 0 is a possible value. You probably want them both greater than 1, which clamps the endpoints to zero.

Also, it’s possible to have either α or β or both be less than 1, but this creates very different behavior: the corresponding endpoints become poles.

Anyway, something like α = β = 3 is probably close enough to normal for most purposes but already clamped for you. And you could easily replicate something like, say, NetHack’s incredibly bizarre rnz function.

Random frequency

Say you want some event to have an 80% chance to happen every second. You (who am I kidding, I) might be tempted to do something like this:

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if random() < 0.8 * dt:
    do_thing()

In an ideal world, dt is always the same and is equal to 1 / f, where f is the framerate. Replace that 80% with a variable, say P, and every tic you have a P / f chance to do the… whatever it is.

Each second, f tics pass, so you’ll make this check f times. The chance that any check succeeds is the inverse of the chance that every check fails, which is \(1 – \left(1 – \frac{P}{f}\right)^f\).

For P of 80% and a framerate of 60, that’s a total probability of 55.3%. Wait, what?

Consider what happens if the framerate is 2. On the first tic, you roll 0.4 twice — but probabilities are combined by multiplying, and splitting work up by dt only works for additive quantities. You lose some accuracy along the way. If you’re dealing with something that multiplies, you need an exponent somewhere.

But in this case, maybe you don’t want that at all. Each separate roll you make might independently succeed, so it’s possible (but very unlikely) that the event will happen 60 times within a single second! Or 200 times, if that’s someone’s framerate.

If you explicitly want something to have a chance to happen on a specific interval, you have to check on that interval. If you don’t have a gizmo handy to run code on an interval, it’s easy to do yourself with a time buffer:

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timer += dt
# here, 1 is the "every 1 seconds"
while timer > 1:
    timer -= 1
    if random() < 0.8:
        do_thing()

Using while means rolls still happen even if you somehow skipped over an entire second.

(For the curious, and the nerds who already noticed: the expression \(1 – \left(1 – \frac{P}{f}\right)^f\) converges to a specific value! As the framerate increases, it becomes a better and better approximation for \(1 – e^{-P}\), which for the example above is 0.551. Hey, 60 fps is pretty accurate — it’s just accurately representing something nowhere near what I wanted. Er, you wanted.)

Rolling your own

Of course, you can fuss with the classic [0, 1] uniform value however you want. If I want a bias towards zero, I’ll often just square it, or multiply two of them together. If I want a bias towards one, I’ll take a square root. If I want something like a Gaussian/normal distribution, but with clearly-defined endpoints, I might add together n rolls and divide by n. (The normal distribution is just what you get if you roll infinite dice and divide by infinity!)

It’d be nice to be able to understand exactly what this will do to the distribution. Unfortunately, that requires some calculus, which this post is too small to contain, and which I didn’t even know much about myself until I went down a deep rabbit hole while writing, and which in many cases is straight up impossible to express directly.

Here’s the non-calculus bit. A source of randomness is often graphed as a PDF — a probability density function. You’ve almost certainly seen a bell curve graphed, and that’s a PDF. They’re pretty nice, since they do exactly what they look like: they show the relative chance that any given value will pop out. On a bog standard bell curve, there’s a peak at zero, and of course zero is the most common result from a normal distribution.

(Okay, actually, since the results are continuous, it’s vanishingly unlikely that you’ll get exactly zero — but you’re much more likely to get a value near zero than near any other number.)

For the uniform distribution, which is what a classic rand() gives you, the PDF is just a straight horizontal line — every result is equally likely.


If there were a calculus bit, it would go here! Instead, we can cheat. Sometimes. Mathematica knows how to work with probability distributions in the abstract, and there’s a free web version you can use. For the example of squaring a uniform variable, try this out:

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PDF[TransformedDistribution[u^2, u \[Distributed] UniformDistribution[{0, 1}]], u]

(The \[Distributed] is a funny tilde that doesn’t exist in Unicode, but which Mathematica uses as a first-class operator. Also, press shiftEnter to evaluate the line.)

This will tell you that the distribution is… \(\frac{1}{2\sqrt{u}}\). Weird! You can plot it:

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Plot[%, {u, 0, 1}]

(The % refers to the result of the last thing you did, so if you want to try several of these, you can just do Plot[PDF[…], u] directly.)

The resulting graph shows that numbers around zero are, in fact, vastly — infinitely — more likely than anything else.

What about multiplying two together? I can’t figure out how to get Mathematica to understand this, but a great amount of digging revealed that the answer is -ln x, and from there you can plot them both on Wolfram Alpha. They’re similar, though squaring has a much better chance of giving you high numbers than multiplying two separate rolls — which makes some sense, since if either of two rolls is a low number, the product will be even lower.

What if you know the graph you want, and you want to figure out how to play with a uniform roll to get it? Good news! That’s a whole thing called inverse transform sampling. All you have to do is take an integral. Good luck!


This is all extremely ridiculous. New tactic: Just Simulate The Damn Thing. You already have the code; run it a million times, make a histogram, and tada, there’s your PDF. That’s one of the great things about computers! Brute-force numerical answers are easy to come by, so there’s no excuse for producing something like rnz. (Though, be sure your histogram has sufficiently narrow buckets — I tried plotting one for rnz once and the weird stuff on the left side didn’t show up at all!)

By the way, I learned something from futzing with Mathematica here! Taking the square root (to bias towards 1) gives a PDF that’s a straight diagonal line, nothing like the hyperbola you get from squaring (to bias towards 0). How do you get a straight line the other way? Surprise: \(1 – \sqrt{1 – u}\).

Okay, okay, here’s the actual math

I don’t claim to have a very firm grasp on this, but I had a hell of a time finding it written out clearly, so I might as well write it down as best I can. This was a great excuse to finally set up MathJax, too.

Say \(u(x)\) is the PDF of the original distribution and \(u\) is a representative number you plucked from that distribution. For the uniform distribution, \(u(x) = 1\). Or, more accurately,

$$
u(x) = \begin{cases}
1 & \text{ if } 0 \le x \lt 1 \\
0 & \text{ otherwise }
\end{cases}
$$

Remember that \(x\) here is a possible outcome you want to know about, and the PDF tells you the relative probability that a roll will be near it. This PDF spits out 1 for every \(x\), meaning every number between 0 and 1 is equally likely to appear.

We want to do something to that PDF, which creates a new distribution, whose PDF we want to know. I’ll use my original example of \(f(u) = u^2\), which creates a new PDF \(v(x)\).

The trick is that we need to work in terms of the cumulative distribution function for \(u\). Where the PDF gives the relative chance that a roll will be (“near”) a specific value, the CDF gives the relative chance that a roll will be less than a specific value.

The conventions for this seem to be a bit fuzzy, and nobody bothers to explain which ones they’re using, which makes this all the more confusing to read about… but let’s write the CDF with a capital letter, so we have \(U(x)\). In this case, \(U(x) = x\), a straight 45° line (at least between 0 and 1). With the definition I gave, this should make sense. At some arbitrary point like 0.4, the value of the PDF is 1 (0.4 is just as likely as anything else), and the value of the CDF is 0.4 (you have a 40% chance of getting a number from 0 to 0.4).

Calculus ahoy: the PDF is the derivative of the CDF, which means it measures the slope of the CDF at any point. For \(U(x) = x\), the slope is always 1, and indeed \(u(x) = 1\). See, calculus is easy.

Okay, so, now we’re getting somewhere. What we want is the CDF of our new distribution, \(V(x)\). The CDF is defined as the probability that a roll \(v\) will be less than \(x\), so we can literally write:

$$V(x) = P(v \le x)$$

(This is why we have to work with CDFs, rather than PDFs — a PDF gives the chance that a roll will be “nearby,” whatever that means. A CDF is much more concrete.)

What is \(v\), exactly? We defined it ourselves; it’s the do something applied to a roll from the original distribution, or \(f(u)\).

$$V(x) = P\!\left(f(u) \le x\right)$$

Now the first tricky part: we have to solve that inequality for \(u\), which means we have to do something, backwards to \(x\).

$$V(x) = P\!\left(u \le f^{-1}(x)\right)$$

Almost there! We now have a probability that \(u\) is less than some value, and that’s the definition of a CDF!

$$V(x) = U\!\left(f^{-1}(x)\right)$$

Hooray! Now to turn these CDFs back into PDFs, all we need to do is differentiate both sides and use the chain rule. If you never took calculus, don’t worry too much about what that means!

$$v(x) = u\!\left(f^{-1}(x)\right)\left|\frac{d}{dx}f^{-1}(x)\right|$$

Wait! Where did that absolute value come from? It takes care of whether \(f(x)\) increases or decreases. It’s the least interesting part here by far, so, whatever.

There’s one more magical part here when using the uniform distribution — \(u(\dots)\) is always equal to 1, so that entire term disappears! (Note that this only works for a uniform distribution with a width of 1; PDFs are scaled so the entire area under them sums to 1, so if you had a rand() that could spit out a number between 0 and 2, the PDF would be \(u(x) = \frac{1}{2}\).)

$$v(x) = \left|\frac{d}{dx}f^{-1}(x)\right|$$

So for the specific case of modifying the output of rand(), all we have to do is invert, then differentiate. The inverse of \(f(u) = u^2\) is \(f^{-1}(x) = \sqrt{x}\) (no need for a ± since we’re only dealing with positive numbers), and differentiating that gives \(v(x) = \frac{1}{2\sqrt{x}}\). Done! This is also why square root comes out nicer; inverting it gives \(x^2\), and differentiating that gives \(2x\), a straight line.

Incidentally, that method for turning a uniform distribution into any distribution — inverse transform sampling — is pretty much the same thing in reverse: integrate, then invert. For example, when I saw that taking the square root gave \(v(x) = 2x\), I naturally wondered how to get a straight line going the other way, \(v(x) = 2 – 2x\). Integrating that gives \(2x – x^2\), and then you can use the quadratic formula (or just ask Wolfram Alpha) to solve \(2x – x^2 = u\) for \(x\) and get \(f(u) = 1 – \sqrt{1 – u}\).

Multiply two rolls is a bit more complicated; you have to write out the CDF as an integral and you end up doing a double integral and wow it’s a mess. The only thing I’ve retained is that you do a division somewhere, which then gets integrated, and that’s why it ends up as \(-\ln x\).

And that’s quite enough of that! (Okay but having math in my blog is pretty cool and I will definitely be doing more of this, sorry, not sorry.)

Random vs varied

Sometimes, random isn’t actually what you want. We tend to use the word “random” casually to mean something more like chaotic, i.e., with no discernible pattern. But that’s not really random. In fact, given how good humans can be at finding incidental patterns, they aren’t all that unlikely! Consider that when you roll two dice, they’ll come up either the same or only one apart almost half the time. Coincidence? Well, yes.

If you ask for randomness, you’re saying that any outcome — or series of outcomes — is acceptable, including five heads in a row or five tails in a row. Most of the time, that’s fine. Some of the time, it’s less fine, and what you really want is variety. Here are a couple examples and some fairly easy workarounds.

NPC quips

The nature of games is such that NPCs will eventually run out of things to say, at which point further conversation will give the player a short brush-off quip — a slight nod from the designer to the player that, hey, you hit the end of the script.

Some NPCs have multiple possible quips and will give one at random. The trouble with this is that it’s very possible for an NPC to repeat the same quip several times in a row before abruptly switching to another one. With only a few options to choose from, getting the same option twice or thrice (especially across an entire game, which may have numerous NPCs) isn’t all that unlikely. The notion of an NPC quip isn’t very realistic to start with, but having someone repeat themselves and then abruptly switch to something else is especially jarring.

The easy fix is to show the quips in order! Paradoxically, this is more consistently varied than choosing at random — the original “order” is likely to be meaningless anyway, and it already has the property that the same quip can never appear twice in a row.

If you like, you can shuffle the list of quips every time you reach the end, but take care here — it’s possible that the last quip in the old order will be the same as the first quip in the new order, so you may still get a repeat. (Of course, you can just check for this case and swap the first quip somewhere else if it bothers you.)

That last behavior is, in fact, the canonical way that Tetris chooses pieces — the game simply shuffles a list of all 7 pieces, gives those to you in shuffled order, then shuffles them again to make a new list once it’s exhausted. There’s no avoidance of duplicates, though, so you can still get two S blocks in a row, or even two S and two Z all clumped together, but no more than that. Some Tetris variants take other approaches, such as actively avoiding repeats even several pieces apart or deliberately giving you the worst piece possible.

Random drops

Random drops are often implemented as a flat chance each time. Maybe enemies have a 5% chance to drop health when they die. Legally speaking, over the long term, a player will see health drops for about 5% of enemy kills.

Over the short term, they may be desperate for health and not survive to see the long term. So you may want to put a thumb on the scale sometimes. Games in the Metroid series, for example, have a somewhat infamous bias towards whatever kind of drop they think you need — health if your health is low, missiles if your missiles are low.

I can’t give you an exact approach to use, since it depends on the game and the feeling you’re going for and the variables at your disposal. In extreme cases, you might want to guarantee a health drop from a tough enemy when the player is critically low on health. (Or if you’re feeling particularly evil, you could go the other way and deny the player health when they most need it…)

The problem becomes a little different, and worse, when the event that triggers the drop is relatively rare. The pathological case here would be something like a raid boss in World of Warcraft, which requires hours of effort from a coordinated group of people to defeat, and which has some tiny chance of dropping a good item that will go to only one of those people. This is why I stopped playing World of Warcraft at 60.

Dialing it back a little bit gives us Enter the Gungeon, a roguelike where each room is a set of encounters and each floor only has a dozen or so rooms. Initially, you have a 1% chance of getting a reward after completing a room — but every time you complete a room and don’t get a reward, the chance increases by 9%, up to a cap of 80%. Once you get a reward, the chance resets to 1%.

The natural question is: how frequently, exactly, can a player expect to get a reward? We could do math, or we could Just Simulate The Damn Thing.

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from collections import Counter
import random

histogram = Counter()

TRIALS = 1000000
chance = 1
rooms_cleared = 0
rewards_found = 0
while rewards_found < TRIALS:
    rooms_cleared += 1
    if random.random() * 100 < chance:
        # Reward!
        rewards_found += 1
        histogram[rooms_cleared] += 1
        rooms_cleared = 0
        chance = 1
    else:
        chance = min(80, chance + 9)

for gaps, count in sorted(histogram.items()):
    print(f"{gaps:3d} | {count / TRIALS * 100:6.2f}%", '#' * (count // (TRIALS // 100)))
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  1 |   0.98%
  2 |   9.91% #########
  3 |  17.00% ################
  4 |  20.23% ####################
  5 |  19.21% ###################
  6 |  15.05% ###############
  7 |   9.69% #########
  8 |   5.07% #####
  9 |   2.09% ##
 10 |   0.63%
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 12 |   0.03%
 13 |   0.00%
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We’ve got kind of a hilly distribution, skewed to the left, which is up in this histogram. Most of the time, a player should see a reward every three to six rooms, which is maybe twice per floor. It’s vanishingly unlikely to go through a dozen rooms without ever seeing a reward, so a player should see at least one per floor.

Of course, this simulated a single continuous playthrough; when starting the game from scratch, your chance at a reward always starts fresh at 1%, the worst it can be. If you want to know about how many rewards a player will get on the first floor, hey, Just Simulate The Damn Thing.

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  0 |   0.01%
  1 |  13.01% #############
  2 |  56.28% ########################################################
  3 |  27.49% ###########################
  4 |   3.10% ###
  5 |   0.11%
  6 |   0.00%

Cool. Though, that’s assuming exactly 12 rooms; it might be worth changing that to pick at random in a way that matches the level generator.

(Enter the Gungeon does some other things to skew probability, which is very nice in a roguelike where blind luck can make or break you. For example, if you kill a boss without having gotten a new gun anywhere else on the floor, the boss is guaranteed to drop a gun.)

Critical hits

I suppose this is the same problem as random drops, but backwards.

Say you have a battle sim where every attack has a 6% chance to land a devastating critical hit. Presumably the same rules apply to both the player and the AI opponents.

Consider, then, that the AI opponents have exactly the same 6% chance to ruin the player’s day. Consider also that this gives them an 0.4% chance to critical hit twice in a row. 0.4% doesn’t sound like much, but across an entire playthrough, it’s not unlikely that a player might see it happen and find it incredibly annoying.

Perhaps it would be worthwhile to explicitly forbid AI opponents from getting consecutive critical hits.

In conclusion

An emerging theme here has been to Just Simulate The Damn Thing. So consider Just Simulating The Damn Thing. Even a simple change to a random value can do surprising things to the resulting distribution, so unless you feel like differentiating the inverse function of your code, maybe test out any non-trivial behavior and make sure it’s what you wanted. Probability is hard to reason about.

Steal This Show S03E12: Attack Of The Propaganda Bots

Post Syndicated from J.J. King original https://torrentfreak.com/steal-show-s03e12-attack-propaganda-bots/

stslogo180If you enjoy this episode, consider becoming a patron and getting involved with the show. Check out Steal This Show’s Patreon campaign: support us and get all kinds of fantastic benefits!

In this episode, we meet Sam Woolley, director of the Digital Intelligence Lab at the Institute for the Future, to dig deeper into the topic of troll farms, political disinformation and the use of social media bots to create what Sam calls ‘Computational Propaganda’.

What happens when the ability to create propaganda is democratized out of the hands of governments and corporate media and into the hands of unknown, weird and downright dangerous online actors?

Steal This Show aims to release bi-weekly episodes featuring insiders discussing copyright and file-sharing news. It complements our regular reporting by adding more room for opinion, commentary, and analysis.

The guests for our news discussions will vary, and we’ll aim to introduce voices from different backgrounds and persuasions. In addition to news, STS will also produce features interviewing some of the great innovators and minds.

Host: Jamie King

Guest: Sam Woolley

Produced by Jamie King
Edited & Mixed by Riley Byrne
Original Music by David Triana
Web Production by Siraje Amarniss

Source: TF, for the latest info on copyright, file-sharing, torrent sites and more. We also have VPN discounts, offers and coupons

Protecting code integrity with PGP

Post Syndicated from jake original https://lwn.net/Articles/741454/rss

Linux Foundation Director of IT infrastructure security, Konstantin Ryabitsev, has put together a lengthy guide to using Git and PGP to protect the integrity of source code. In a Google+ post, he called it “beta quality” and asked for help with corrections and fixes. “PGP incorporates a trust delegation mechanism known as the ‘Web of Trust.’ At its core, this is an attempt to replace the need for centralized Certification Authorities of the HTTPS/TLS world. Instead of various software makers dictating who should be your trusted certifying entity, PGP leaves this responsibility to each user.

Unfortunately, very few people understand how the Web of Trust works, and even fewer bother to keep it going. It remains an important aspect of the OpenPGP specification, but recent versions of GnuPG (2.2 and above) have implemented an alternative mechanism called ‘Trust on First Use’ (TOFU).

You can think of TOFU as ‘the SSH-like approach to trust.’ With SSH, the first time you connect to a remote system, its key fingerprint is recorded and remembered. If the key changes in the future, the SSH client will alert you and refuse to connect, forcing you to make a decision on whether you choose to trust the changed key or not.

Similarly, the first time you import someone’s PGP key, it is assumed to be trusted. If at any point in the future GnuPG comes across another key with the same identity, both the previously imported key and the new key will be marked as invalid and you will need to manually figure out which one to keep.

In this guide, we will be using the TOFU trust model.”

What is HAMR and How Does It Enable the High-Capacity Needs of the Future?

Post Syndicated from Andy Klein original https://www.backblaze.com/blog/hamr-hard-drives/

HAMR drive illustration

During Q4, Backblaze deployed 100 petabytes worth of Seagate hard drives to our data centers. The newly deployed Seagate 10 and 12 TB drives are doing well and will help us meet our near term storage needs, but we know we’re going to need more drives — with higher capacities. That’s why the success of new hard drive technologies like Heat-Assisted Magnetic Recording (HAMR) from Seagate are very relevant to us here at Backblaze and to the storage industry in general. In today’s guest post we are pleased to have Mark Re, CTO at Seagate, give us an insider’s look behind the hard drive curtain to tell us how Seagate engineers are developing the HAMR technology and making it market ready starting in late 2018.

What is HAMR and How Does It Enable the High-Capacity Needs of the Future?

Guest Blog Post by Mark Re, Seagate Senior Vice President and Chief Technology Officer

Earlier this year Seagate announced plans to make the first hard drives using Heat-Assisted Magnetic Recording, or HAMR, available by the end of 2018 in pilot volumes. Even as today’s market has embraced 10TB+ drives, the need for 20TB+ drives remains imperative in the relative near term. HAMR is the Seagate research team’s next major advance in hard drive technology.

HAMR is a technology that over time will enable a big increase in the amount of data that can be stored on a disk. A small laser is attached to a recording head, designed to heat a tiny spot on the disk where the data will be written. This allows a smaller bit cell to be written as either a 0 or a 1. The smaller bit cell size enables more bits to be crammed into a given surface area — increasing the areal density of data, and increasing drive capacity.

It sounds almost simple, but the science and engineering expertise required, the research, experimentation, lab development and product development to perfect this technology has been enormous. Below is an overview of the HAMR technology and you can dig into the details in our technical brief that provides a point-by-point rundown describing several key advances enabling the HAMR design.

As much time and resources as have been committed to developing HAMR, the need for its increased data density is indisputable. Demand for data storage keeps increasing. Businesses’ ability to manage and leverage more capacity is a competitive necessity, and IT spending on capacity continues to increase.

History of Increasing Storage Capacity

For the last 50 years areal density in the hard disk drive has been growing faster than Moore’s law, which is a very good thing. After all, customers from data centers and cloud service providers to creative professionals and game enthusiasts rarely go shopping looking for a hard drive just like the one they bought two years ago. The demands of increasing data on storage capacities inevitably increase, thus the technology constantly evolves.

According to the Advanced Storage Technology Consortium, HAMR will be the next significant storage technology innovation to increase the amount of storage in the area available to store data, also called the disk’s “areal density.” We believe this boost in areal density will help fuel hard drive product development and growth through the next decade.

Why do we Need to Develop Higher-Capacity Hard Drives? Can’t Current Technologies do the Job?

Why is HAMR’s increased data density so important?

Data has become critical to all aspects of human life, changing how we’re educated and entertained. It affects and informs the ways we experience each other and interact with businesses and the wider world. IDC research shows the datasphere — all the data generated by the world’s businesses and billions of consumer endpoints — will continue to double in size every two years. IDC forecasts that by 2025 the global datasphere will grow to 163 zettabytes (that is a trillion gigabytes). That’s ten times the 16.1 ZB of data generated in 2016. IDC cites five key trends intensifying the role of data in changing our world: embedded systems and the Internet of Things (IoT), instantly available mobile and real-time data, cognitive artificial intelligence (AI) systems, increased security data requirements, and critically, the evolution of data from playing a business background to playing a life-critical role.

Consumers use the cloud to manage everything from family photos and videos to data about their health and exercise routines. Real-time data created by connected devices — everything from Fitbit, Alexa and smart phones to home security systems, solar systems and autonomous cars — are fueling the emerging Data Age. On top of the obvious business and consumer data growth, our critical infrastructure like power grids, water systems, hospitals, road infrastructure and public transportation all demand and add to the growth of real-time data. Data is now a vital element in the smooth operation of all aspects of daily life.

All of this entails a significant infrastructure cost behind the scenes with the insatiable, global appetite for data storage. While a variety of storage technologies will continue to advance in data density (Seagate announced the first 60TB 3.5-inch SSD unit for example), high-capacity hard drives serve as the primary foundational core of our interconnected, cloud and IoT-based dependence on data.

HAMR Hard Drive Technology

Seagate has been working on heat assisted magnetic recording (HAMR) in one form or another since the late 1990s. During this time we’ve made many breakthroughs in making reliable near field transducers, special high capacity HAMR media, and figuring out a way to put a laser on each and every head that is no larger than a grain of salt.

The development of HAMR has required Seagate to consider and overcome a myriad of scientific and technical challenges including new kinds of magnetic media, nano-plasmonic device design and fabrication, laser integration, high-temperature head-disk interactions, and thermal regulation.

A typical hard drive inside any computer or server contains one or more rigid disks coated with a magnetically sensitive film consisting of tiny magnetic grains. Data is recorded when a magnetic write-head flies just above the spinning disk; the write head rapidly flips the magnetization of one magnetic region of grains so that its magnetic pole points up or down, to encode a 1 or a 0 in binary code.

Increasing the amount of data you can store on a disk requires cramming magnetic regions closer together, which means the grains need to be smaller so they won’t interfere with each other.

Heat Assisted Magnetic Recording (HAMR) is the next step to enable us to increase the density of grains — or bit density. Current projections are that HAMR can achieve 5 Tbpsi (Terabits per square inch) on conventional HAMR media, and in the future will be able to achieve 10 Tbpsi or higher with bit patterned media (in which discrete dots are predefined on the media in regular, efficient, very dense patterns). These technologies will enable hard drives with capacities higher than 100 TB before 2030.

The major problem with packing bits so closely together is that if you do that on conventional magnetic media, the bits (and the data they represent) become thermally unstable, and may flip. So, to make the grains maintain their stability — their ability to store bits over a long period of time — we need to develop a recording media that has higher coercivity. That means it’s magnetically more stable during storage, but it is more difficult to change the magnetic characteristics of the media when writing (harder to flip a grain from a 0 to a 1 or vice versa).

That’s why HAMR’s first key hardware advance required developing a new recording media that keeps bits stable — using high anisotropy (or “hard”) magnetic materials such as iron-platinum alloy (FePt), which resist magnetic change at normal temperatures. Over years of HAMR development, Seagate researchers have tested and proven out a variety of FePt granular media films, with varying alloy composition and chemical ordering.

In fact the new media is so “hard” that conventional recording heads won’t be able to flip the bits, or write new data, under normal temperatures. If you add heat to the tiny spot on which you want to write data, you can make the media’s coercive field lower than the magnetic field provided by the recording head — in other words, enable the write head to flip that bit.

So, a challenge with HAMR has been to replace conventional perpendicular magnetic recording (PMR), in which the write head operates at room temperature, with a write technology that heats the thin film recording medium on the disk platter to temperatures above 400 °C. The basic principle is to heat a tiny region of several magnetic grains for a very short time (~1 nanoseconds) to a temperature high enough to make the media’s coercive field lower than the write head’s magnetic field. Immediately after the heat pulse, the region quickly cools down and the bit’s magnetic orientation is frozen in place.

Applying this dynamic nano-heating is where HAMR’s famous “laser” comes in. A plasmonic near-field transducer (NFT) has been integrated into the recording head, to heat the media and enable magnetic change at a specific point. Plasmonic NFTs are used to focus and confine light energy to regions smaller than the wavelength of light. This enables us to heat an extremely small region, measured in nanometers, on the disk media to reduce its magnetic coercivity,

Moving HAMR Forward

HAMR write head

As always in advanced engineering, the devil — or many devils — is in the details. As noted earlier, our technical brief provides a point-by-point short illustrated summary of HAMR’s key changes.

Although hard work remains, we believe this technology is nearly ready for commercialization. Seagate has the best engineers in the world working towards a goal of a 20 Terabyte drive by 2019. We hope we’ve given you a glimpse into the amount of engineering that goes into a hard drive. Keeping up with the world’s insatiable appetite to create, capture, store, secure, manage, analyze, rapidly access and share data is a challenge we work on every day.

With thousands of HAMR drives already being made in our manufacturing facilities, our internal and external supply chain is solidly in place, and volume manufacturing tools are online. This year we began shipping initial units for customer tests, and production units will ship to key customers by the end of 2018. Prepare for breakthrough capacities.

The post What is HAMR and How Does It Enable the High-Capacity Needs of the Future? appeared first on Backblaze Blog | Cloud Storage & Cloud Backup.

Digital making for new parents

Post Syndicated from Carrie Anne Philbin original https://www.raspberrypi.org/blog/digital-making-for-new-parents/

Solving problems that are meaningful to us is at the core of our approach to teaching and learning about technology here at the Raspberry Pi Foundation. Over the last eight months, I’ve noticed that the types of digital making projects that motivate and engage me have changed (can’t think why). Always looking for ways to save money and automate my life and the lives of my loved ones, I’ve been thinking a lot about how digital making projects could be the new best friend of any new parent.

A baby, oblivious to the amount its parents have spent on stuff they never knew existed last year.
Image: sweet baby by MRef photography / CC BY-ND 2.0

Baby Monitor

I never knew how much equipment one small child needs until very recently. I also had no idea of the range of technology that is on offer to support you as a new parent to ensure the perfect environment outside of the womb. Baby monitors are at the top of this list. There are lots of Raspberry Pi baby monitor projects with a range of sensing functionality already in existence, and we’ve blogged about some of them before. They’re a great example of how an understanding of technology can open up a range of solutions that won’t break the bank. I’m looking forward to using all the capabilities of the Raspberry Pi to keep an eye on baby.

Baby name generator

Another surprising discovery was just how difficult it is to name a human being. Surprising because I can give a name to an inanimate object in less than three seconds, and come up with nicknames for colleagues in less than a day. My own offspring, though, and I draw a blank. The only solution: write a Python program to randomly generate names based on some parameters!

import names
from time import sleep
from guizero import App, ButtonGroup, Text, PushButton, TextBox

def get_name():
    boyname = names.get_first_name(gender='male')
    girlname = names.get_first_name(gender='female')
    othername = names.get_first_name()

    if babygender.get() == "male":
        name.set(str(boyname)+" "+str(babylastname.get()))
    elif babygender.get() == "female":
        name.set(str(girlname)+" "+str(babylastname.get()))
    else:
        name.set(str(othername)+" "+str(babylastname.get()))

app = App("Baby name generator")
surname_label = Text(app, "What is your surname?")
babylastname = TextBox(app, width=50)
babygender = ButtonGroup(app, options=[["boy", "male"], ["girl", "female"], ["all", "all"]], selected="male", horizontal=True)
intro = Text(app, "Your baby name could be")
name = Text(app, "")
button = PushButton(app, get_name, text="Generate me a name")

app.display()

Thanks to the names and GUIZero Python libraries, it is super simple to create, resolving any possible parent-to-be naming disputes in mere minutes.

Food, Poo, or Love?

I love data. Not just in Star Trek, but also more generally. Collecting and analysing data to understand my sleep patterns, my eating habits, how much exercise I do, and how much time I spend watching YouTube videos consumes much of my time. So of course I want to know lots about the little person we’ve made, long before he can use language to tell us himself.

I’m told that most newborns’ needs are quite simple: they want food, they want to be changed, or they just want some cuddles. I’m certain it’s more complicated than this, but it’s a good starting point for a data set, so stick with me here. I also wondered whether there might be a correlation between the amplitude of the cry and the type of need the baby has. A bit of an imprecise indicator, maybe, but fun to start to think about.

This build’s success is mostly thanks to Pimoroni’s Rainbow HAT, which, conveniently, has three capacitive touch buttons to record the newborn’s need, four fourteen-segment displays to display the words “FOOD”, “POO”, and “LOVE” when a button is pressed, and seven multicoloured LEDs to indicate the ferociousness of the baby’s cry in glorious technicolour. With the addition of a microphone, the ‘Food, Poo, Love Machine’ was born. Here it is in action:

Food Poo Love – Raspberry Pi Baby Monitor Project

Food Poo Love – The Raspberry Pi baby monitor project that allows you to track data on your new born baby.

Automatic Baby mobile

Another project that I’ve not had time to hack on, but that I think would be really awesome, is to automate a baby cot mobile. Imagine this one moving to the Star Trek theme music:

Image courtesy of Gisele Blaker Designs (check out her cool shop!)

Pretty awesome.

If you’ve got any more ideas for baby projects, do let me know. I’ll have a few months of nothing to do… right?

The post Digital making for new parents appeared first on Raspberry Pi.

Weekly roundup: Truth or Dare

Post Syndicated from Eevee original https://eev.ee/dev/2017/12/11/weekly-roundup-truth-or-dare/

Oops, I seem to have missed a week. I was doing Ludum Dare 40, but then I stopped, because— well hang on lemme just bullet this.

  • anise!!: I intended to enter Ludum Dare with glip; we were working on a game about Anise that we’d conceived about a month ago but never gotten around to. We made pretty decent progress, but realized we couldn’t fit anywhere near what we wanted into only three days, so we’re just… running with it. It’s going on a little longer than we wanted, but it’s getting pretty fun to play now, and I guess that’s pretty good progress given that we had absolutely nothing ten days ago. I’m even figuring out AI for once.

  • fox flux: Worked on some portraits and big text and underground tiles. Made some sound effects. Did a whole pretty cool footstep thing that combines particles with footstep noises and is very great.

  • other games: I discovered bitsy, the teeniest game engine I’ve ever seen, and wanted to make something with it — so I made Roguelike Simulator (and also wrote a release post).

  • cc: I got so frustrated with trying to find something in Unity Collab history that I cobbled together a thing for exporting Collab history to git. No, you can’t have it, I’m still not convinced it won’t delete my entire hard drive or something. Also I probably fixed a bug in the actual game somewhere in there.

  • blog: Finally finished that post about object models, only a month late! Hooray! Also wrote a game night post, which may or may not become a series?

Also some other stuff that I’m not ready to share yet.

I have a lot going on and can’t believe the month is a third over yet, but I’m charging forwards!

Managing AWS Lambda Function Concurrency

Post Syndicated from Chris Munns original https://aws.amazon.com/blogs/compute/managing-aws-lambda-function-concurrency/

One of the key benefits of serverless applications is the ease in which they can scale to meet traffic demands or requests, with little to no need for capacity planning. In AWS Lambda, which is the core of the serverless platform at AWS, the unit of scale is a concurrent execution. This refers to the number of executions of your function code that are happening at any given time.

Thinking about concurrent executions as a unit of scale is a fairly unique concept. In this post, I dive deeper into this and talk about how you can make use of per function concurrency limits in Lambda.

Understanding concurrency in Lambda

Instead of diving right into the guts of how Lambda works, here’s an appetizing analogy: a magical pizza.
Yes, a magical pizza!

This magical pizza has some unique properties:

  • It has a fixed maximum number of slices, such as 8.
  • Slices automatically re-appear after they are consumed.
  • When you take a slice from the pizza, it does not re-appear until it has been completely consumed.
  • One person can take multiple slices at a time.
  • You can easily ask to have the number of slices increased, but they remain fixed at any point in time otherwise.

Now that the magical pizza’s properties are defined, here’s a hypothetical situation of some friends sharing this pizza.

Shawn, Kate, Daniela, Chuck, Ian and Avleen get together every Friday to share a pizza and catch up on their week. As there is just six of them, they can easily all enjoy a slice of pizza at a time. As they finish each slice, it re-appears in the pizza pan and they can take another slice again. Given the magical properties of their pizza, they can continue to eat all they want, but with two very important constraints:

  • If any of them take too many slices at once, the others may not get as much as they want.
  • If they take too many slices, they might also eat too much and get sick.

One particular week, some of the friends are hungrier than the rest, taking two slices at a time instead of just one. If more than two of them try to take two pieces at a time, this can cause contention for pizza slices. Some of them would wait hungry for the slices to re-appear. They could ask for a pizza with more slices, but then run the same risk again later if more hungry friends join than planned for.

What can they do?

If the friends agreed to accept a limit for the maximum number of slices they each eat concurrently, both of these issues are avoided. Some could have a maximum of 2 of the 8 slices, or other concurrency limits that were more or less. Just so long as they kept it at or under eight total slices to be eaten at one time. This would keep any from going hungry or eating too much. The six friends can happily enjoy their magical pizza without worry!

Concurrency in Lambda

Concurrency in Lambda actually works similarly to the magical pizza model. Each AWS Account has an overall AccountLimit value that is fixed at any point in time, but can be easily increased as needed, just like the count of slices in the pizza. As of May 2017, the default limit is 1000 “slices” of concurrency per AWS Region.

Also like the magical pizza, each concurrency “slice” can only be consumed individually one at a time. After consumption, it becomes available to be consumed again. Services invoking Lambda functions can consume multiple slices of concurrency at the same time, just like the group of friends can take multiple slices of the pizza.

Let’s take our example of the six friends and bring it back to AWS services that commonly invoke Lambda:

  • Amazon S3
  • Amazon Kinesis
  • Amazon DynamoDB
  • Amazon Cognito

In a single account with the default concurrency limit of 1000 concurrent executions, any of these four services could invoke enough functions to consume the entire limit or some part of it. Just like with the pizza example, there is the possibility for two issues to pop up:

  • One or more of these services could invoke enough functions to consume a majority of the available concurrency capacity. This could cause others to be starved for it, causing failed invocations.
  • A service could consume too much concurrent capacity and cause a downstream service or database to be overwhelmed, which could cause failed executions.

For Lambda functions that are launched in a VPC, you have the potential to consume the available IP addresses in a subnet or the maximum number of elastic network interfaces to which your account has access. For more information, see Configuring a Lambda Function to Access Resources in an Amazon VPC. For information about elastic network interface limits, see Network Interfaces section in the Amazon VPC Limits topic.

One way to solve both of these problems is applying a concurrency limit to the Lambda functions in an account.

Configuring per function concurrency limits

You can now set a concurrency limit on individual Lambda functions in an account. The concurrency limit that you set reserves a portion of your account level concurrency for a given function. All of your functions’ concurrent executions count against this account-level limit by default.

If you set a concurrency limit for a specific function, then that function’s concurrency limit allocation is deducted from the shared pool and assigned to that specific function. AWS also reserves 100 units of concurrency for all functions that don’t have a specified concurrency limit set. This helps to make sure that future functions have capacity to be consumed.

Going back to the example of the consuming services, you could set throttles for the functions as follows:

Amazon S3 function = 350
Amazon Kinesis function = 200
Amazon DynamoDB function = 200
Amazon Cognito function = 150
Total = 900

With the 100 reserved for all non-concurrency reserved functions, this totals the account limit of 1000.

Here’s how this works. To start, create a basic Lambda function that is invoked via Amazon API Gateway. This Lambda function returns a single “Hello World” statement with an added sleep time between 2 and 5 seconds. The sleep time simulates an API providing some sort of capability that can take a varied amount of time. The goal here is to show how an API that is underloaded can reach its concurrency limit, and what happens when it does.
To create the example function

  1. Open the Lambda console.
  2. Choose Create Function.
  3. For Author from scratch, enter the following values:
    1. For Name, enter a value (such as concurrencyBlog01).
    2. For Runtime, choose Python 3.6.
    3. For Role, choose Create new role from template and enter a name aligned with this function, such as concurrencyBlogRole.
  4. Choose Create function.
  5. The function is created with some basic example code. Replace that code with the following:

import time
from random import randint
seconds = randint(2, 5)

def lambda_handler(event, context):
time.sleep(seconds)
return {"statusCode": 200,
"body": ("Hello world, slept " + str(seconds) + " seconds"),
"headers":
{
"Access-Control-Allow-Headers": "Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token",
"Access-Control-Allow-Methods": "GET,OPTIONS",
}}

  1. Under Basic settings, set Timeout to 10 seconds. While this function should only ever take up to 5-6 seconds (with the 5-second max sleep), this gives you a little bit of room if it takes longer.

  1. Choose Save at the top right.

At this point, your function is configured for this example. Test it and confirm this in the console:

  1. Choose Test.
  2. Enter a name (it doesn’t matter for this example).
  3. Choose Create.
  4. In the console, choose Test again.
  5. You should see output similar to the following:

Now configure API Gateway so that you have an HTTPS endpoint to test against.

  1. In the Lambda console, choose Configuration.
  2. Under Triggers, choose API Gateway.
  3. Open the API Gateway icon now shown as attached to your Lambda function:

  1. Under Configure triggers, leave the default values for API Name and Deployment stage. For Security, choose Open.
  2. Choose Add, Save.

API Gateway is now configured to invoke Lambda at the Invoke URL shown under its configuration. You can take this URL and test it in any browser or command line, using tools such as “curl”:


$ curl https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01
Hello world, slept 2 seconds

Throwing load at the function

Now start throwing some load against your API Gateway + Lambda function combo. Right now, your function is only limited by the total amount of concurrency available in an account. For this example account, you might have 850 unreserved concurrency out of a full account limit of 1000 due to having configured a few concurrency limits already (also the 100 concurrency saved for all functions without configured limits). You can find all of this information on the main Dashboard page of the Lambda console:

For generating load in this example, use an open source tool called “hey” (https://github.com/rakyll/hey), which works similarly to ApacheBench (ab). You test from an Amazon EC2 instance running the default Amazon Linux AMI from the EC2 console. For more help with configuring an EC2 instance, follow the steps in the Launch Instance Wizard.

After the EC2 instance is running, SSH into the host and run the following:


sudo yum install go
go get -u github.com/rakyll/hey

“hey” is easy to use. For these tests, specify a total number of tests (5,000) and a concurrency of 50 against the API Gateway URL as follows(replace the URL here with your own):


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01

The output from “hey” tells you interesting bits of information:


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01

Summary:
Total: 381.9978 secs
Slowest: 9.4765 secs
Fastest: 0.0438 secs
Average: 3.2153 secs
Requests/sec: 13.0891
Total data: 140024 bytes
Size/request: 28 bytes

Response time histogram:
0.044 [1] |
0.987 [2] |
1.930 [0] |
2.874 [1803] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
3.817 [1518] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
4.760 [719] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
5.703 [917] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
6.647 [13] |
7.590 [14] |
8.533 [9] |
9.477 [4] |

Latency distribution:
10% in 2.0224 secs
25% in 2.0267 secs
50% in 3.0251 secs
75% in 4.0269 secs
90% in 5.0279 secs
95% in 5.0414 secs
99% in 5.1871 secs

Details (average, fastest, slowest):
DNS+dialup: 0.0003 secs, 0.0000 secs, 0.0332 secs
DNS-lookup: 0.0000 secs, 0.0000 secs, 0.0046 secs
req write: 0.0000 secs, 0.0000 secs, 0.0005 secs
resp wait: 3.2149 secs, 0.0438 secs, 9.4472 secs
resp read: 0.0000 secs, 0.0000 secs, 0.0004 secs

Status code distribution:
[200] 4997 responses
[502] 3 responses

You can see a helpful histogram and latency distribution. Remember that this Lambda function has a random sleep period in it and so isn’t entirely representational of a real-life workload. Those three 502s warrant digging deeper, but could be due to Lambda cold-start timing and the “second” variable being the maximum of 5, causing the Lambda functions to time out. AWS X-Ray and the Amazon CloudWatch logs generated by both API Gateway and Lambda could help you troubleshoot this.

Configuring a concurrency reservation

Now that you’ve established that you can generate this load against the function, I show you how to limit it and protect a backend resource from being overloaded by all of these requests.

  1. In the console, choose Configure.
  2. Under Concurrency, for Reserve concurrency, enter 25.

  1. Click on Save in the top right corner.

You could also set this with the AWS CLI using the Lambda put-function-concurrency command or see your current concurrency configuration via Lambda get-function. Here’s an example command:


$ aws lambda get-function --function-name concurrencyBlog01 --output json --query Concurrency
{
"ReservedConcurrentExecutions": 25
}

Either way, you’ve set the Concurrency Reservation to 25 for this function. This acts as both a limit and a reservation in terms of making sure that you can execute 25 concurrent functions at all times. Going above this results in the throttling of the Lambda function. Depending on the invoking service, throttling can result in a number of different outcomes, as shown in the documentation on Throttling Behavior. This change has also reduced your unreserved account concurrency for other functions by 25.

Rerun the same load generation as before and see what happens. Previously, you tested at 50 concurrency, which worked just fine. By limiting the Lambda functions to 25 concurrency, you should see rate limiting kick in. Run the same test again:


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01

While this test runs, refresh the Monitoring tab on your function detail page. You see the following warning message:

This is great! It means that your throttle is working as configured and you are now protecting your downstream resources from too much load from your Lambda function.

Here is the output from a new “hey” command:


$ ./go/bin/hey -n 5000 -c 50 https://ofixul557l.execute-api.us-east-1.amazonaws.com/prod/concurrencyBlog01
Summary:
Total: 379.9922 secs
Slowest: 7.1486 secs
Fastest: 0.0102 secs
Average: 1.1897 secs
Requests/sec: 13.1582
Total data: 164608 bytes
Size/request: 32 bytes

Response time histogram:
0.010 [1] |
0.724 [3075] |∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎∎
1.438 [0] |
2.152 [811] |∎∎∎∎∎∎∎∎∎∎∎
2.866 [11] |
3.579 [566] |∎∎∎∎∎∎∎
4.293 [214] |∎∎∎
5.007 [1] |
5.721 [315] |∎∎∎∎
6.435 [4] |
7.149 [2] |

Latency distribution:
10% in 0.0130 secs
25% in 0.0147 secs
50% in 0.0205 secs
75% in 2.0344 secs
90% in 4.0229 secs
95% in 5.0248 secs
99% in 5.0629 secs

Details (average, fastest, slowest):
DNS+dialup: 0.0004 secs, 0.0000 secs, 0.0537 secs
DNS-lookup: 0.0002 secs, 0.0000 secs, 0.0184 secs
req write: 0.0000 secs, 0.0000 secs, 0.0016 secs
resp wait: 1.1892 secs, 0.0101 secs, 7.1038 secs
resp read: 0.0000 secs, 0.0000 secs, 0.0005 secs

Status code distribution:
[502] 3076 responses
[200] 1924 responses

This looks fairly different from the last load test run. A large percentage of these requests failed fast due to the concurrency throttle failing them (those with the 0.724 seconds line). The timing shown here in the histogram represents the entire time it took to get a response between the EC2 instance and API Gateway calling Lambda and being rejected. It’s also important to note that this example was configured with an edge-optimized endpoint in API Gateway. You see under Status code distribution that 3076 of the 5000 requests failed with a 502, showing that the backend service from API Gateway and Lambda failed the request.

Other uses

Managing function concurrency can be useful in a few other ways beyond just limiting the impact on downstream services and providing a reservation of concurrency capacity. Here are two other uses:

  • Emergency kill switch
  • Cost controls

Emergency kill switch

On occasion, due to issues with applications I’ve managed in the past, I’ve had a need to disable a certain function or capability of an application. By setting the concurrency reservation and limit of a Lambda function to zero, you can do just that.

With the reservation set to zero every invocation of a Lambda function results in being throttled. You could then work on the related parts of the infrastructure or application that aren’t working, and then reconfigure the concurrency limit to allow invocations again.

Cost controls

While I mentioned how you might want to use concurrency limits to control the downstream impact to services or databases that your Lambda function might call, another resource that you might be cautious about is money. Setting the concurrency throttle is another way to help control costs during development and testing of your application.

You might want to prevent against a function performing a recursive action too quickly or a development workload generating too high of a concurrency. You might also want to protect development resources connected to this function from generating too much cost, such as APIs that your Lambda function calls.

Conclusion

Concurrent executions as a unit of scale are a fairly unique characteristic about Lambda functions. Placing limits on how many concurrency “slices” that your function can consume can prevent a single function from consuming all of the available concurrency in an account. Limits can also prevent a function from overwhelming a backend resource that isn’t as scalable.

Unlike monolithic applications or even microservices where there are mixed capabilities in a single service, Lambda functions encourage a sort of “nano-service” of small business logic directly related to the integration model connected to the function. I hope you’ve enjoyed this post and configure your concurrency limits today!

Roguelike Simulator

Post Syndicated from Eevee original https://eev.ee/release/2017/12/09/roguelike-simulator/

Screenshot of a monochromatic pixel-art game designed to look mostly like ASCII text

On a recent game night, glip and I stumbled upon bitsy — a tiny game maker for “games where you can walk around and talk to people and be somewhere.” It’s enough of a genre to have become a top tag on itch, so we flicked through a couple games.

What we found were tiny windows into numerous little worlds, ill-defined yet crisply rendered in chunky two-colored pixels. Indeed, all you can do is walk around and talk to people and be somewhere, but the somewheres are strangely captivating. My favorite was the last days of our castle, with a day on the town in a close second (though it cheated and extended the engine a bit), but there are several hundred of these tiny windows available. Just single, short, minimal, interactive glimpses of an idea.

I’ve been wanting to do more of that, so I gave it a shot today. The result is Roguelike Simulator, a game that condenses the NetHack experience into about ninety seconds.


Constraints breed creativity, and bitsy is practically made of constraints — the only place you can even make any decisions at all is within dialogue trees. There are only three ways to alter the world: the player can step on an ending tile to end the game, step on an exit tile to instantly teleport to a tile on another map (or not), or pick up an item. That’s it. You can’t even implement keys; the best you can do is make an annoying maze of identical rooms, then have an NPC tell you the solution.

In retrospect, a roguelike — a genre practically defined by its randomness — may have been a poor choice.

I had a lot of fun faking it, though, and it worked well enough to fool at least one person for a few minutes! Some choice hacks follow. Probably play the game a couple times before reading them?

  • Each floor reveals itself, of course, by teleporting you between maps with different chunks of the floor visible. I originally intended for this to be much more elaborate, but it turns out to be a huge pain to juggle multiple copies of the same floor layout.

  • Endings can’t be changed or randomized; even the text is static. I still managed to implement multiple variants on the “ascend” ending! See if you can guess how. (It’s not that hard.)

  • There are no Boolean operators, but there are arithmetic operators, so in one place I check whether you have both of two items by multiplying together how many of each you have.

  • Monsters you “defeat” are actually just items you pick up. They’re both drawn in the same color, and you can’t see your inventory, so you can’t tell the difference.

Probably the best part was writing the text, which is all completely ridiculous. I really enjoy writing a lot of quips — which I guess is why I like Twitter — and I’m happy to see they’ve made people laugh!


I think this has been a success! It’s definitely made me more confident about making smaller things — and about taking the first idea I have and just running with it. I’m going to keep an eye out for other micro game engines to play with, too.

The Raspberry Pi Christmas shopping list 2017

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/christmas-shopping-list-2017/

Looking for the perfect Christmas gift for a beloved maker in your life? Maybe you’d like to give a relative or friend a taste of the world of coding and Raspberry Pi? Whatever you’re looking for, the Raspberry Pi Christmas shopping list will point you in the right direction.

An ice-skating Raspberry Pi - The Raspberry Pi Christmas Shopping List 2017

For those getting started

Thinking about introducing someone special to the wonders of Raspberry Pi during the holidays? Although you can set up your Pi with peripherals from around your home, such as a mobile phone charger, your PC’s keyboard, and the old mouse dwelling in an office drawer, a starter kit is a nice all-in-one package for the budding coder.



Check out the starter kits from Raspberry Pi Approved Resellers such as Pimoroni, The Pi Hut, ModMyPi, Adafruit, CanaKit…the list is pretty long. Our products page will direct you to your closest reseller, or you can head to element14 to pick up the official Raspberry Pi Starter Kit.



You can also buy the Raspberry Pi Press’s brand-new Raspberry Pi Beginners Book, which includes a Raspberry Pi Zero W, a case, a ready-made SD card, and adapter cables.

Once you’ve presented a lucky person with their first Raspberry Pi, it’s time for them to spread their maker wings and learn some new skills.

MagPi Essentials books - The Raspberry Pi Christmas Shopping List 2017

To help them along, you could pick your favourite from among the Official Projects Book volume 3, The MagPi Essentials guides, and the brand-new third edition of Carrie Anne Philbin’s Adventures in Raspberry Pi. (She is super excited about this new edition!)

And you can always add a link to our free resources on the gift tag.

For the maker in your life

If you’re looking for something for a confident digital maker, you can’t go wrong with adding to their arsenal of electric and electronic bits and bobs that are no doubt cluttering drawers and boxes throughout their house.



Components such as servomotors, displays, and sensors are staples of the maker world. And when it comes to jumper wires, buttons, and LEDs, one can never have enough.



You could also consider getting your person a soldering iron, some helpings hands, or small tools such as a Dremel or screwdriver set.

And to make their life a little less messy, pop it all inside a Really Useful Box…because they’re really useful.



For kit makers

While some people like to dive into making head-first and to build whatever comes to mind, others enjoy working with kits.



The Naturebytes kit allows you to record the animal visitors of your garden with the help of a camera and a motion sensor. Footage of your local badgers, birds, deer, and more will be saved to an SD card, or tweeted or emailed to you if it’s in range of WiFi.

Cortec Tiny 4WD - The Raspberry Pi Christmas Shopping List 2017

Coretec’s Tiny 4WD is a kit for assembling a Pi Zero–powered remote-controlled robot at home. Not only is the robot adorable, building it also a great introduction to motors and wireless control.



Bare Conductive’s Touch Board Pro Kit offers everything you need to create interactive electronics projects using conductive paint.

Pi Hut Arcade Kit - The Raspberry Pi Christmas Shopping List 2017

Finally, why not help your favourite maker create their own gaming arcade using the Arcade Building Kit from The Pi Hut?

For the reader

For those who like to curl up with a good read, or spend too much of their day on public transport, a book or magazine subscription is the perfect treat.

For makers, hackers, and those interested in new technologies, our brand-new HackSpace magazine and the ever popular community magazine The MagPi are ideal. Both are available via a physical or digital subscription, and new subscribers to The MagPi also receive a free Raspberry Pi Zero W plus case.

Cover of CoderDojo Nano Make your own game

Marc Scott Beginner's Guide to Coding Book

You can also check out other publications from the Raspberry Pi family, including CoderDojo’s new CoderDojo Nano: Make Your Own Game, Eben Upton and Gareth Halfacree’s Raspberry Pi User Guide, and Marc Scott’s A Beginner’s Guide to Coding. And have I mentioned Carrie Anne’s Adventures in Raspberry Pi yet?

Stocking fillers for everyone

Looking for something small to keep your loved ones occupied on Christmas morning? Or do you have to buy a Secret Santa gift for the office tech? Here are some wonderful stocking fillers to fill your boots with this season.

Pi Hut 3D Christmas Tree - The Raspberry Pi Christmas Shopping List 2017

The Pi Hut 3D Xmas Tree: available as both a pre-soldered and a DIY version, this gadget will work with any 40-pin Raspberry Pi and allows you to create your own mini light show.



Google AIY Voice kit: build your own home assistant using a Raspberry Pi, the MagPi Essentials guide, and this brand-new kit. “Google, play Mariah Carey again…”



Pimoroni’s Raspberry Pi Zero W Project Kits offer everything you need, including the Pi, to make your own time-lapse cameras, music players, and more.



The official Raspberry Pi Sense HAT, Camera Module, and cases for the Pi 3 and Pi Zero will complete the collection of any Raspberry Pi owner, while also opening up exciting project opportunities.

STEAM gifts that everyone will love

Awesome Astronauts | Building LEGO’s Women of NASA!

LEGO Idea’s bought out this amazing ‘Women of NASA’ set, and I thought it would be fun to build, play and learn from these inspiring women! First up, let’s discover a little more about Sally Ride and Mae Jemison, two AWESOME ASTRONAUTS!

Treat the kids, and big kids, in your life to the newest LEGO Ideas set, the Women of NASA — starring Nancy Grace Roman, Margaret Hamilton, Sally Ride, and Mae Jemison!



Explore the world of wearables with Pimoroni’s sewable, hackable, wearable, adorable Bearables kits.



Add lights and motors to paper creations with the Activating Origami Kit, available from The Pi Hut.




We all loved Hidden Figures, and the STEAM enthusiast you know will do too. The film’s available on DVD, and you can also buy the original book, along with other fascinating non-fiction such as Rebecca Skloot’s The Immortal Life of Henrietta Lacks, Rachel Ignotofsky’s Women in Science, and Sydney Padua’s (mostly true) The Thrilling Adventures of Lovelace and Babbage.

Have we missed anything?

With so many amazing kits, HATs, and books available from members of the Raspberry Pi community, it’s hard to only pick a few. Have you found something splendid for the maker in your life? Maybe you’ve created your own kit that uses the Raspberry Pi? Share your favourites with us in the comments below or via our social media accounts.

The post The Raspberry Pi Christmas shopping list 2017 appeared first on Raspberry Pi.

The Pi Towers Secret Santa Babbage

Post Syndicated from Mark Calleja original https://www.raspberrypi.org/blog/secret-santa-babbage/

Tired of pulling names out of a hat for office Secret Santa? Upgrade your festive tradition with a Raspberry Pi, thermal printer, and everybody’s favourite microcomputer mascot, Babbage Bear.

Raspberry Pi Babbage Bear Secret Santa

The name’s Santa. Secret Santa.

It’s that time of year again, when the cosiness gets turned up to 11 and everyone starts thinking about jolly fat men, reindeer, toys, and benevolent home invasion. At Raspberry Pi, we’re running a Secret Santa pool: everyone buys a gift for someone else in the office. Obviously, the person you buy for has to be picked in secret and at random, or the whole thing wouldn’t work. With that in mind, I created Secret Santa Babbage to do the somewhat mundane task of choosing gift recipients. This could’ve just been done with some names in a hat, but we’re Raspberry Pi! If we don’t make a Python-based Babbage robot wearing a jaunty hat and programmed to spread Christmas cheer, who will?

Secret Santa Babbage

Ho ho ho!

Mecha-Babbage Xmas shenanigans

The script the robot runs is pretty basic: a list of names entered as comma-separated strings is shuffled at the press of a GPIO button, then a name is popped off the end and stored as a variable. The name is matched to a photo of the person stored on the Raspberry Pi, and a thermal printer pinched from Alex’s super awesome PastyCam (blog post forthcoming, maybe) prints out the picture and name of the person you will need to shower with gifts at the Christmas party. (Well, OK — with one gift. No more than five quid’s worth. Nothing untoward.) There’s also a redo function, just in case you pick yourself: press another button and the last picked name — still stored as a variable — is appended to the list again, which is shuffled once more, and a new name is popped off the end.

Secret Santa Babbage prototyping

Prototyping!

As the build was a bit of a rush job undertaken at the request of our ‘Director of Vibe’ Emily, there are a few things I’d like to improve about this functionality that I didn’t get around to — more on that later. To add some extra holiday spirit to the project at the last minute, I used Pygame to play a WAV file of Santa’s jolly laugh while Babbage chooses a name for you. The file is included in the GitHub repo along with everything else, because ‘tis the season, etc., etc.

Secret Santa Babbage prototyping

Editor’s note: Considering these desk adornments, Mark’s Secret Santa gift-giver has a lot to go on.

Writing the code for Xmas Mecha-Babbage was fairly straightforward, though it uses some tricky bits for managing the thermal printer. You’ll need to install the drivers to make it go, as well as the CUPS package for managing the print hosting. You can find instructions for these things here, thanks to the wonderful Adafruit crew. Also, for reasons I couldn’t fathom, this will all only work on a Pi 2 and not a Pi 3, as there are some compatibility issues with the thermal printer otherwise. (I also tested the script on a Pi Zero W…no dice.)

Building a Christmassy throne

The hardest (well, fiddliest) parts of making the whole build were constructing the throne and wiring the bear. Using MakerCase, Inkscape, a bit of ingenuity, and a laser cutter, I was able to rig up a Christmassy plywood throne which has a hole through the seat so I could run the wires down from Babbage and to the Pi inside. I finished the throne by rubbing a couple of fingers of beeswax into it; as well as making the wood shine just a little bit and protecting it against getting wet, this had the added bonus of making it smell awesome.

Secret Santa Babbage inside

Next year’s iteration will be mulled wine–scented.

I next soldered two LEDs to some lengths of wire, and then ran the wires through holes at the top of the throne and down the back along a small channel I had carved with a narrow chisel to connect them to the Pi’s GPIO pins. The green LED will remain on as long as Babbage is running his program, and the red one will light up while he is processing your request. Once the red LED goes off again, the next person can have a go. I also laser-cut a final piece of wood to overlay the back of Babbage’s Xmas throne and cover the wiring a bit.

Creating a Xmas cyborg bear

Taking two 6 mm tactile buttons, I clipped the spiky metal legs off one side of each (the buttons were going into a stuffed christmas toy, after all) and soldered a length of wire to each of the remaining legs. Next, I made a small incision into Babbage with my trusty Swiss army knife (in a place that actually made me cringe a little) and fed the buttons up into his paws. At some point in this process I was standing in the office wrestling with the bear and muttering to myself, which elicited some very strange looks from my colleagues.

Secret Santa Babbage throne

Poor Babbage…

One thing to note here is to make sure the wires remain attached at the solder points while you push them up into Babbage’s paws. The first time I tried it, I snapped one of my connections and had to start again. It helped to remove some stuffing like a tunnel and then replace it afterward. Moreover, you can use your fingertip to support the joints as you poke the wire in. Finally, a couple of squirts of hot glue to keep Babbage’s furry cheeks firmly on the seat, and done!

Secret Santa Babbage

Next year: Game of Thrones–inspired candy cane throne

The Secret Santa Babbage masterpiece

The whole build process was the perfect holiday mix of cheerful and macabre, and while getting the thermal printer to work was a little time-consuming, the finished product definitely raised some smiles around the office and added a bit of interesting digital flavour to a staid office tradition. And it also helped people who are new to the office or from other branches of the Foundation to know for whom they will be buying a gift.

Secret Santa Babbage

Ready to dispense Christmas cheer!

There are a few ways in which I’ll polish this project before next year, such as having the script write the names to external text files to create a record that will persist in case of a reboot, and maybe having Secret Santa Babbage play you a random Christmas carol when you squeeze his paw instead of just laughing merrily every time. (I also thought about adding electric shocks for those people who are on the naughty list, but HR said no. Bah, humbug!)

Make your own

The code and laser cut plans for the whole build are available here. If you plan to make your own, let us know which stuffed toy you will be turning into a Secret Santa cyborg! And if you’ve been working on any other Christmas-themed Raspberry Pi projects, we’d like to see those too, so tag us on social media to share the festive maker cheer.

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