Apply now for Picademy in Baltimore

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Making computing accessible is a major part of the Raspberry Pi Foundation’s mission. Our low-cost, high-performance computer is just one way that we achieve that. With our Picademy program, we also train teachers so that more young people can learn about computers and how to make things with them.

Throughout 2016, we’re running a United States pilot of Picademy. Raspberry Pi Foundation’s commitment is to train 100 teachers on US soil this year and we’ve made another leap towards meeting that commitment last weekend with our second cohort, but more on that below.

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In order to make Picademy more accessible for US educators, we’re happy to announce our third Picademy USA workshop, which will take place August 13 and 14 at the Digital Harbor Foundation in Baltimore, Maryland. Applications are open now and will close in early July. Please help us spread the word. We want to hear from all of the most enthusiastic and creative educators from all disciplines—not just computing. Picademy cohorts are made up of an incredible mixture of different types of educators from different subject areas. Not only will these educators learn about digital making from the Raspberry Pi education team, but they’ll be meeting and collaborating with a group of incredibly passionate peers.

To give you an idea of the passion and enthusiasm, I want to introduce you to our second US cohort of Raspberry Pi Certified Educators. Last weekend at the Computer History Museum, they gathered from all over North America to learn the ropes of digital making with Raspberry Pi and collaborate on projects together. They knocked it out of the park.

Our superhero Raspberry Pi Certified Educators! © Douglas Fairbairn Photography / Courtesy of the Computer History Museum

Our superhero Raspberry Pi Certified Educators! © Douglas Fairbairn Photography / Courtesy of the Computer History Museum

Peek into the #Picademy hashtag and you’ll get a small taste of what it’s like to be a part of this program:

Abby Almerido on Twitter

Sign of transformative learning = Unquenchable thirst for more #picademy Thank you @LegoJames @MattRichardson @ben_nuttall @olsonk408

Keith Baisley on Twitter

Such a fun/engaging weekend of learning,can’t thank you all enough @LegoJames @MattRichardson @ben_nuttall @EbenUpton and others #picademy

Peter Strawn on Twitter

Home from #Picademy. What an incredible weekend. Thank you, @Raspberry_Pi. Now to reflect and put my experience into action!

Dan Blickensderfer on Twitter

Pinned. What a great community. Thanks! #picademypic.twitter.com/TLLzjff0wF

Making Picademy a success takes a lot of work from many people. Thank you to: Lauren Silver, Kate McGregor, Stephanie Corrigan, and everyone at the Computer History Museum. Kevin Olson, a Raspberry Pi Certified Educator who stepped in to help facilitate the workshops. Kevin Malachowski, Ruchi Lohani, Sam Patterson, Jesse Lozano, and Eben Upton who mentored the educators. Sonia Uppal, Abhinav Mathur, and Keshav Saharia for presenting their amazing work with Raspberry Pi.

If you want to join our tribe and you can be in Baltimore on August 13th and 14th, please apply to be a part of our next Picademy in the United States! For updates on future Picademy workshops in the US, please click here to sign up for notifications.

The post Apply now for Picademy in Baltimore appeared first on Raspberry Pi.

#FreePCB via Twitter to 2 random RTs

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Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week:

  • Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch it every Sunday, right here on the blog
  • Tweet-a-PCB Tuesday. Follow us and get boards in 144 characters or less
  • Facebook PCB Friday. Free PCBs will be your friend for the weekend

Some stuff:

  • Yes, we’ll mail it anywhere in the world!
  • Check out how we mail PCBs worldwide video.
  • We’ll contact you via Twitter with a coupon code for the PCB drawer.
  • Limit one PCB per address per month please.
  • Like everything else on this site, PCBs are offered without warranty.

We try to stagger free PCB posts so every time zone has a chance to participate, but the best way to see it first is to subscribe to the RSS feed, follow us on Twitter, or like us on Facebook.

3V3/30V DC/DC converter using SN6505A

via Dangerous Prototypes

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Robert Gawron made a 3V3/30V DC/DC converter using SN6505A:

Recently I’v got my samples of SN6505A, it’s a really nice IC, so I decided to make a simple DC/DC converter to get familiar with it. What I like in this chip is that it can operate on input voltage as low as 2,5V – that makes it great for battery devices. It’s also nice, that it’s a very minimalist design – on primary side all what is needed is decoupling capacitor. One disadvantage is that it doesn’t have a feedback loop.
To increase efficiency, SN6505A can operate with more developed versions of transformers, but I used the simplest configuration – one coil on each side.

Project info at Robert Gawron’s blog.

Pocket FM: independent radio in Syria

via Raspberry Pi

When we started thinking about the Raspberry Pi project back in 2009, our ambitions were small, and very focussed on local education.

We realised we were doing something bigger than that pretty rapidly, but all the same, some of the projects we come across leave us shocked at their scale, their gravity and their importance. This is one of them.

"Do you have a radio? 87.7 FM"

Do you have a radio? 87.7 FM

In Syria, a German group called Media in Cooperation and Transition (MiCT) has been equipping towns with transmitters called PocketFM, built around Raspberry Pis, to provide Syrians with independent radio. Each transmitter has 4 to 6km (2.5 to 3.75 miles) of range, which is sufficient to reach a whole town.

In many parts of Syria, it’s impossible and politically unwise to build large transmitters, so a small device like PocketFM that can be easily concealed and transported, and that can be run off solar power or a car battery, is ideal.

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A group of around a dozen independent Syrian radio stations has come together to form a group called Syrnet, who work together on programmes and topics and produce a joint station to be broadcast via the PocketFM transmitters; MiCT deal with the mix, distribution and transmission. “The variety of voices in a broadcast effectively illustrates Syria’s state of mind,” says one of the broadcasters. Using PocketFM, Syrnet is reaching 1.5 million citizens in north and north-western Syria, including Homs and Aleppo; they are currently making efforts to widen the network to more regions.

radio stations

The project is about enabling freedom of expression; it also strengthens feelings of solidarity. “We are not for anyone, or against anyone. No one can escape our criticism, even ourselves.”

Between them, the participating stations have access to hundreds of reporters. As well as news, music and entertainment, they’re broadcasting vital information on security, health and nutrition. “One of our strongest programmes is called Alternatives. It describes how to keep warm without any fuel, or how to pick up the internet signal of neighbouring countries when the Syrian internet is down. The difficulties of life – and how to overcome them.”

Syria Radio Network

Syria Radio Network (Syrnet) is an initiative to support independent radio production in Syria with professional training and outreach. Syrnet is a mixed live programme, sourced from Syrian radio stations. Our program is available 24 hours and seven days a week.

In a warzone, radio can be one of the easiest ways to get information. If the power grid is down, you just need batteries.

“We lost one device in Kobane”, says Philipp Hochleichter from MiCT, who is the project’s technical lead. “But due to the bombing – not due to a malfunction.”

“At the moment our journalists are safe with the opposition, but it’s still a war zone with gunfire and shelling,” said Marwa, a journalist with Hara FM, one of the Syrnet stations, based in Turkey.

“I worry about our staff in Aleppo, but no journalist can be 100% safe anywhere in the world.

“For any journalist, telling the truth puts them in danger.”

These bold people are doing something extraordinary. We send them all our very best wishes, and our hopes for a swift end to the conflict.

The post Pocket FM: independent radio in Syria appeared first on Raspberry Pi.

HOW-TO: Add live websites to GIT without interruptions or security risks

via Dangerous Prototypes

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Over at the DEV site we’ve been using GIT repositories hosted at BitBucket.org to push (deploy) changes to the live server instantly. It’s way slicker than uploading changed files by FTP, which has no roll back if something goes wrong. It also solves one of our China internet problems: routing to Bitbucket is much more reliable than to our servers in Germany.

It is finally time to merge the DEV site with the main Dangerous Prototypes sites – the blog got a new theme yesterday. When we started updating the rest of the site it seemed much easier and safer to put it in GIT too. There are a lot of tutorials about deploying websites with GIT, but none completely covered the process to safely put existing websites into GIT with no interruptions and maximum security.

Updating folder structure

We’re starting off with a legacy folder structure rooted in early cloud services and personal ignorance. The web root is at /var/www/. Other parts of the site (/forum, /docs) sit in subfolders of the root:

/www/ (WordPress blog)
/www/forum (phpBB forum)
/www/docs (MediaWiki wiki)

This isn’t how modern websites are structured. It’s super amateur, but it’s worked for years. We’ll change this to use Apache virtual directories when the dev site is merged with this site.

Use an external repo folder for security

“git init” would create a new repo around the entire website giving instant version control. It would also put the git config folder and files on the live web leaving a big security hole! It also binds together the five different web apps running on this server into a single giant mess.

git clone –mirror git@bitbucket.org:dangercore/wordpress.git repo-wordpress

After creating a free GIT repo at BitBucket.org called “wordpress” and setting up the SSH keys we’re really to roll. We cloned the empty repo into our home folder (~) on the server, keeping all the repo files out of the reach from the web.

cd repo-wordpress
GIT_WORK_TREE=/var/www git status

The GIT_WORK_TREE variable links the live website directory (/var/www) with the new repo in our home folder (~/repo-wordpress). The status command will show untracked files in the /var/www directory.

At this point you might think we should protect the git folders and config files with .htaccess instead of including the annoying GIT_WORK_TREE constant with every GIT command. We could, but then all changes would need to include that security for the life of the website. Blocking access is a patch against a vulnerability, better to never have the vulnerability in the first place.

.gitignore stuff

# Exclude files from the git repo
wp-content/cache/*
wp-content/media/*

# Include these files in previously blocked directories
!wp-content/media/.htaccess

#other software in root
docs/*
forum/*

Not everything belongs in our repo. 8 years of blog images and cache files take up a ton of space in a repo and we don’t need them to push code updates. We do, however, want to keep the .htaccess file in the media folder that prevents users browsing the contents of that directory.

We also want to exclude the other sites mixed into the webroot (docs/,forum/). We’ll push them into their own repos later using the same process. Put these rules in the .gitignore file in the GIT_WORK_TREE folder (/var/www for us). This is a short example .gitignore based on this, see our complete ignore files for all the sites in the forum!

GIT_WORK_TREE=/var/www git status

Check file status again. Ignored directories should not be on the list.

Add, Commit, Push

GIT_WORK_TREE=/var/www git add .

GIT is now tracking these files.

GIT_WORK_TREE=/var/www git status

See a list of the files being tracked.

GIT_WORK_TREE=/var/www git commit -m”Initial commit”

Commit the files to the local repo. Now we have a snapshot of the site code.

GIT_WORK_TREE=/var/www git push

Push from local repo to the remote repo at BitBucket. The site snapshot is now also stored at BitBucket.

Pull hooks for automatic updates

BitBucket and GitHub have a ‘hook’ feature that loads a URL after every push to the repo. We setup BitBucket to load a “secret” webpage on the server that triggers a git pull command whenever we push an update to the master branch. ServerPilot has some more info and a nice script that we modified.

Next steps

/apps/ (Folder of GIT repos)
/apps/wordpress/ (WordPress GIT repo with notes, tools, etc)
/apps/wordpress/public/ (Live public folder accessible on the web)

We want to end up with a structure where each area of the site (/forum,/docs,/blog) is an Apache virtual directory or symlink to a public subfolder inside a git repository. Instead of serving WordPress directly from the repo (/apps/wordpress/), we serve it from a subfolder inside the repo called “public” (/apps/wordpress/public).

First, this keeps the git folder and configuration files off web without the annoying GIT_WORK_TREE variable in each command. Second, we can use the main folder for other stuff that might be handy to have in the repository but shouldn’t be public: notes, database updates, sample files and data, test tools, etc.

We’re redeploying each site area like this as the new themes are finished. When the dust is settled we’ll document the final server setup that should last well into the future.