Schlagwort: Our Staff

The answers to your questions for Eben Upton

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Before Easter, we asked you to tell us your questions for a live Q & A with Raspberry Pi Trading CEO and Raspberry Pi creator Eben Upton. The variety of questions and comments you sent was wonderful, and while we couldn’t get to them all, we picked a handful of the most common to grill him on.

You can watch the video below — though due to this being the first pancake of our live Q&A videos, the sound is a bit iffy — or read Eben’s answers to the first five questions today. We’ll follow up with the rest in the next few weeks!

Live Q&A with Eben Upton, creator of the Raspberry Pi

Get your questions to us now using #AskRaspberryPi on Twitter

Any plans for 64-bit Raspbian?

Raspbian is effectively 32-bit Debian built for the ARMv6 instruction-set architecture supported by the ARM11 processor in the first-generation Raspberry Pi. So maybe the question should be: “Would we release a version of our operating environment that was built on top of 64-bit ARM Debian?”

And the answer is: “Not yet.”

When we released the Raspberry Pi 3 Model B+, we released an operating system image on the same day; the wonderful thing about that image is that it runs on every Raspberry Pi ever made. It even runs on the alpha boards from way back in 2011.

That deep backwards compatibility is really important for us, in large part because we don’t want to orphan our customers. If someone spent $35 on an older-model Raspberry Pi five or six years ago, they still spent $35, so it would be wrong for us to throw them under the bus.

Raspberry Pi 1 Model A+

So, if we were going to do a 64-bit version, we’d want to keep doing the 32-bit version, and then that would mean our efforts would be split across the two versions; and remember, we’re still a very small engineering team. Never say never, but it would be a big step for us.

For people wanting a 64-bit operating system, there are plenty of good third-party images out there, including SUSE Linux Enterprise Server.

Given that the 3B+ includes 5GHz wireless and Power over Ethernet (PoE) support, why would manufacturers continue to use the Compute Module?

It’s a form-factor thing.

Compute Module IO Board V3

Very large numbers of people are using the bigger product in an industrial context, and it’s well engineered for that: it has module certification, wireless on board, and now PoE support. But there are use cases that can’t accommodate this form factor. For example, NEC displays: we’ve had this great relationship with NEC for a couple of years now where a lot of their displays have a socket in the back that you can put a Compute Module into. That wouldn’t work with the 3B+ form factor.

An NEC display with a Raspberry Pi Compute Module

What are some industrial uses/products Raspberry is used with?

The NEC displays are a good example of the broader trend of using Raspberry Pi in digital signage.

A Raspberry Pi running the wait time signage at The Wizarding World of Harry Potter, Universal Studios.
Image c/o thelonelyredditor1

If you see a monitor at a station, or an airport, or a recording studio, and you look behind it, it’s amazing how often you’ll find a Raspberry Pi sitting there. The original Raspberry Pi was particularly strong for multimedia use cases, so we saw uptake in signage very early on.

Los Alamos Raspberry Pi supercomputer

Another great example is the Los Alamos National Laboratory building supercomputers out of Raspberry Pis. Many high-end supercomputers now are built using white-box hardware — just regular PCs connected together using some networking fabric — and a collection of Raspberry Pi units can serve as a scale model of that. The Raspberry Pi has less processing power, less memory, and less networking bandwidth than the PC, but it has a balanced amount of each. So if you don’t want to let your apprentice supercomputer engineers loose on your expensive supercomputer, a cluster of Raspberry Pis is a good alternative.

Why is there no power button on the Raspberry Pi?

“Once you start, where do you stop?” is a question we ask ourselves a lot.

There are a whole bunch of useful things that we haven’t included in the Raspberry Pi by default. We don’t have a power button, we don’t have a real-time clock, and we don’t have an analogue-to-digital converter — those are probably the three most common requests. And the issue with them is that they each cost a bit of money, they’re each only useful to a minority of users, and even that minority often can’t agree on exactly what they want. Some people would like a power button that is literally a physical analogue switch between the 5V input and the rest of the board, while others would like something a bit more like a PC power button, which is partway between a physical switch and a ‘shutdown’ button. There’s no consensus about what sort of power button we should add.

So the answer is: accessories. By leaving a feature off the board, we’re not taxing the majority of people who don’t want the feature. And of course, we create an opportunity for other companies in the ecosystem to create and sell accessories to those people who do want them.

The Adafruit Push-button Power Switch Breakout is one of many accessories that fill in the gaps for makers.

We have this neat way of figuring out what features to include by default: we divide through the fraction of people who want it. If you have a 20 cent component that’s going to be used by a fifth of people, we treat that as if it’s a $1 component. And it has to fight its way against the $1 components that will be used by almost everybody.

Do you think that Raspberry Pi is the future of the Internet of Things?

Absolutely, Raspberry Pi is the future of the Internet of Things!

In practice, most of the viable early IoT use cases are in the commercial and industrial spaces rather than the consumer space. Maybe in ten years’ time, IoT will be about putting 10-cent chips into light switches, but right now there’s so much money to be saved by putting automation into factories that you don’t need 10-cent components to address the market. Last year, roughly 2 million $35 Raspberry Pi units went into commercial and industrial applications, and many of those are what you’d call IoT applications.

So I think we’re the future of a particular slice of IoT. And we have ten years to get our price point down to 10 cents 🙂

Website: LINK

13/04/2018
Alex’s quick and easy digital making Easter egg hunt

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Looking to incorporate some digital making into your Easter weekend? You’ve come to the right place! With a Raspberry Pi, a few wires, and some simple code, you can take your festivities to the next level — here’s how!

If you logged in to watch our Instagram live-stream yesterday, you’ll have seen me put together a simple egg carton and some wires to create circuits. These circuits, when closed by way of a foil-wrapped chocolate egg, instruct a Raspberry Pi to reveal the whereabouts of a larger chocolate egg!

Make it

You’ll need an egg carton, two male-to-female jumper wire, and two crocodile leads for each egg you use.

Connect your leads together in pairs: one end of a crocodile lead to the male end of one jumper wire. Attach the free crocodile clips of two leads to each corner of the egg carton (as shown up top). Then hook up the female ends to GPIO pins: one numbered pin and one ground pin per egg. I recommend pins 3, 4, 18 and 24, as they all have adjacent GND pins.

Your foil-wrapped Easter egg will complete the circuit — make sure it’s touching both the GPIO- and GND-connected clips when resting in the carton.

Wrap it

For your convenience (and our sweet tooth), we tested several foil-wrapped eggs (Easter and otherwise) to see which are conductive.

Raspberry Pi on Twitter

We’re egg-sperimenting with Easter deliciousness to find which treat is the most conductive. Why? All will be revealed in our Instagram Easter live-stream tomorrow.

The result? None of them are! But if you unwrap an egg and rewrap it with the non-decorative foil side outward, this tends to work. You could also use aluminium foil or copper tape to create a conductive layer.

Code it

Next, you’ll need to create the code for your hunt. The script below contains the bare bones needed to make the project work — you can embellish it however you wish using GUIs, flashing LEDs, music, etc.

Open Thonny or IDLE on Raspbian and create a new file called egghunt.py. Then enter the following code:

We’re using ButtonBoard from the gpiozero library. This allows us to link several buttons together as an object and set an action for when any number of the buttons are pressed. Here, the script waits for all four circuits to be completed before printing the location of the prize in the Python shell.

Your turn

And that’s it! Now you just need to hide your small foil eggs around the house and challenge your kids/friends/neighbours to find them. Then, once every circuit is completed with an egg, the great prize will be revealed.

Give it a go this weekend! And if you do, be sure to let us know on social media.

(Thank you to Lauren Hyams for suggesting we “do something for Easter” and Ben ‘gpiozero’ Nuttall for introducing me to ButtonBoard.)

Website: LINK

28/03/2018
Coding is for girls
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Less than four years ago, Magda Jadach was convinced that programming wasn’t for girls. On International Women’s Day, she tells us how she discovered that it definitely is, and how she embarked on the new career that has brought her to Raspberry Pi as a software developer.

“Coding is for boys”, “in order to be a developer you have to be some kind of super-human”, and “it’s too late to learn how to code” – none of these three things is true, and I am going to prove that to you in this post. By doing this I hope to help some people to get involved in the tech industry and digital making. Programming is for anyone who loves to create and loves to improve themselves.

In the summer of 2014, I started the journey towards learning how to code. I attended my first coding workshop at the recommendation of my boyfriend, who had constantly told me about the skill and how great it was to learn. I was convinced that, at 28 years old, I was already too old to learn. I didn’t have a technical background, I was under the impression that “coding is for boys”, and I lacked the superpowers I was sure I needed. I decided to go to the workshop only to prove him wrong.

Later on, I realised that coding is a skill like any other. You can compare it to learning any language: there’s grammar, vocabulary, and other rules to acquire.

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Alien message in console

To my surprise, the workshop was completely inspiring. Within six hours I was able to create my first web page. It was a really simple page with a few cats, some colours, and ‘Hello world’ text. This was a few years ago, but I still remember when I first clicked “view source” to inspect the page. It looked like some strange alien message, as if I’d somehow broken the computer.

I wanted to learn more, but with so many options, I found myself a little overwhelmed. I’d never taught myself any technical skill before, and there was a lot of confusing jargon and new terms to get used to. What was HTML? CSS and JavaScript? What were databases, and how could I connect together all the dots and choose what I wanted to learn? Luckily I had support and was able to keep going.

At times, I felt very isolated. Was I the only girl learning to code? I wasn’t aware of many female role models until I started going to more workshops. I met a lot of great female developers, and thanks to their support and help, I kept coding.

Another struggle I faced was the language barrier. I am not a native speaker of English, and diving into English technical documentation wasn’t easy. The learning curve is daunting in the beginning, but it’s completely normal to feel uncomfortable and to think that you’re really bad at coding. Don’t let this bring you down. Everyone thinks this from time to time.

Play with Raspberry Pi and quit your job

I kept on improving my skills, and my interest in developing grew. However, I had no idea that I could do this for a living; I simply enjoyed coding. Since I had a day job as a journalist, I was learning in the evenings and during the weekends.

I spent long hours playing with a Raspberry Pi and setting up so many different projects to help me understand how the internet and computers work, and get to grips with the basics of electronics. I built my first ever robot buggy, retro game console, and light switch. For the first time in my life, I had a soldering iron in my hand. Day after day I become more obsessed with digital making.

Magdalena Jadach on Twitter

solderingiron Where have you been all my life? Weekend with #raspberrypi + @pimoroni + @Pololu + #solder = best time! #electricity

One day I realised that I couldn’t wait to finish my job and go home to finish some project that I was working on at the time. It was then that I decided to hand over my resignation letter and dive deep into coding.

For the next few months I completely devoted my time to learning new skills and preparing myself for my new career path.

I went for an interview and got my first ever coding internship. Two years, hundreds of lines of code, and thousands of hours spent in front of my computer later, I have landed my dream job at the Raspberry Pi Foundation as a software developer, which proves that dreams come true.

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Discover & share this Animated GIF with everyone you know. GIPHY is how you search, share, discover, and create GIFs.

Where to start?

I recommend starting with HTML & CSS – the same path that I chose. It is a relatively straightforward introduction to web development. You can follow my advice or choose a different approach. There is no “right” or “best” way to learn.

Below is a collection of free coding resources, both from Raspberry Pi and from elsewhere, that I think are useful for beginners to know about. There are other tools that you are going to want in your developer toolbox aside from HTML.
- HTML and CSS are languages for describing, structuring, and styling web pages
- You can learn JavaScript here and here
- Raspberry Pi (obviously!) and our online learning projects
- Scratch is a graphical programming language that lets you drag and combine code blocks to make a range of programs. It’s a good starting point
- Git is version control software that helps you to work on your own projects and collaborate with other developers
- Once you’ve got started, you will need a code editor. Sublime Text or Atom are great options for starting out
Coding gives you so much new inspiration, you learn new stuff constantly, and you meet so many amazing people who are willing to help you develop your skills. You can volunteer to help at a Code Club or Coder Dojo to increase your exposure to code, or attend a Raspberry Jam to meet other like-minded makers and start your own journey towards becoming a developer.

Website: LINK
08/03/2018
Digital making for new parents
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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?

Website: LINK
14/12/2017
The Pi Towers Secret Santa Babbage

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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.

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?

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.

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.

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.

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.

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!

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.

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.

Website: LINK

05/12/2017
What do you want your button to do?
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Here at Raspberry Pi, we know that getting physical with computing is often a catalyst for creativity. Building a simple circuit can open up a world of making possibilities! This ethos of tinkering and invention is also being used in the classroom to inspire a whole new generation of makers too, and here is why.

The all-important question

Physical computing provides a great opportunity for creative expression: the button press! By explaining how a button works, how to build one with a breadboard attached to computer, and how to program the button to work when it’s pressed, you can give learners young and old all the conceptual skills they need to build a thing that does something. But what do they want their button to do? Have you ever asked your students or children at home? I promise it will be one of the most mindblowing experiences you’ll have if you do.

Looks harmless now, but put it into the hands of a child and see what happens!

Amy will want her button to take a photo, Charlie will want his button to play a sound, Tumi will want her button to explode TNT in Minecraft, Jack will want their button to fire confetti out of a cannon, and James Robinson will want his to trigger silly noises (doesn’t he always?)! Idea generation is the inherent gift that every child has in abundance. As educators and parents, we’re always looking to deeply engage our young people in the subject matter we’re teaching, and they are never more engaged than when they have an idea and want to implement it. Way back in 2012, I wanted my button to print geeky sayings:

Geek Gurl Diaries Raspberry Pi Thermal Printer Project Sneak Peek!

A sneak peek at the finished Geek Gurl Diaries ‘Box of Geek’. I’ve been busy making this for a few weeks with some help from friends. Tutorial to make your own box coming soon, so keep checking the Geek Gurl Diaries Twitter, facebook page and channel.

What are the challenges for this approach in education?

Allowing this kind of free-form creativity and tinkering in the classroom obviously has its challenges for teachers, especially those confined to rigid lesson structures, timings, and small classrooms. The most common worry I hear from teachers is “what if they ask a question I can’t answer?” Encouraging this sort of creative thinking makes that almost an inevitability. How can you facilitate roughly 30 different projects simultaneously? The answer is by using those other computational and transferable thinking skills:
- Problem-solving
- Iteration
- Collaboration
- Evaluation
Clearly specifying a problem, surveying the tools available to solve it (including online references and external advice), and then applying them to solve the problem is a hugely important skill, and this is a great opportunity to teach it.

Press ALL the buttons!

Hands-off guidance

When we train teachers at Picademy, we group attendees around themes that have come out of the idea generation session. Together they collaborate on an achievable shared goal. One will often sketch something on a whiteboard, decomposing the problem into smaller parts; then the group will divide up the tasks. Each will look online or in books for tutorials to help them with their step. I’ve seen this behaviour in student groups too, and it’s very easy to facilitate. You don’t need to be the resident expert on every project that students want to work on.

The key is knowing where to guide students to find the answers they need. Curating online videos, blogs, tutorials, and articles in advance gives you the freedom and confidence to concentrate on what matters: the learning. We have a number of physical computing projects that use buttons, linked to our curriculum for learners to combine inputs and outputs to solve a problem. The WhooPi cushion and GPIO music box are two of my favourites.

Outside of formal education, events such as Raspberry Jams, CoderDojos, CAS Hubs, and hackathons are ideal venues for seeking and receiving support and advice.

Cross-curricular participation

The rise of the global maker movement, I think, is in response to abstract concepts and disciplines. Children are taught lots of concepts in isolation that aren’t always relevant to their lives or immediate environment. Digital making provides a unique and exciting way of bridging different subject areas, allowing for cross-curricular participation. I’m not suggesting that educators should throw away all their schemes of work and leave the full direction of the computing curriculum to students. However, there’s huge value in exposing learners to the possibilities for creativity in computing. Creative freedom and expression guide learning, better preparing young people for the workplace of tomorrow.

So…what do you want your button to do?

Hello World

Learn more about today’s subject, and read further articles regarding computer science in education, in Hello World magazine issue 1.

Read Hello World issue 1 for more…

UK-based educators can subscribe to Hello World to receive a hard copy delivered for free to their doorstep, while the PDF is available for free to everyone via the Hello World website.

Website: LINK
22/11/2017
piwheels: making “pip install” fast
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TL;DR pip install numpy used to take ages, and now it’s super fast thanks to piwheels.

The Python Package Index (PyPI) is a package repository for Python modules. Members of the Python community publish software and libraries in it as an easy method of distribution. If you’ve ever used pip install, PyPI is the service that hosts the software you installed. You may have noticed that some installations can take a long time on the Raspberry Pi. That usually happens when modules have been implemented in C and require compilation.

No more slacking off! pip install numpy takes just a few seconds now \o/

Wheels for Python packages

A general solution to this problem exists: Python wheels are a standard for distributing pre-built versions of packages, saving users from having to build from source. However, when C code is compiled, it’s compiled for a particular architecture, so package maintainers usually publish wheels for 32-bit and 64-bit Windows, macOS, and Linux. Although Raspberry Pi runs Linux, its architecture is ARM, so Linux wheels are not compatible.

What Python wheels are not

Pip works by browsing PyPI for a wheel matching the user’s architecture — and if it doesn’t find one, it falls back to the source distribution (usually a tarball or zip of the source code). Then the user has to build it themselves, which can take a long time, or may require certain dependencies. And if pip can’t find a source distribution, the installation fails.

Developing piwheels

In order to solve this problem, I decided to build wheels of every package on PyPI. I wrote some tooling for automating the process and used a postgres database to monitor the status of builds and log the output. Using a Pi 3 in my living room, I attempted to build wheels of the latest version of all 100 000 packages on PyPI and to host them on a web server on the Pi. This took a total of ten days, and my proof-of-concept seemed to show that it generally worked and was likely to be useful! You could install packages directly from the server, and installations were really fast.

This Pi 3 was the piwheels beta server, sitting atop my SSH gateway Pi 2 at home

I proceeded to plan for version 2, which would attempt to build every version of every package — about 750 000 versions in total. I estimated this would take 75 days for one Pi, but I intended to scale it up to use multiple Pis. Our web hosts Mythic Beasts provide dedicated Pi 3 hosting, so I fired up 20 of them to share the load. With some help from Dave Jones, who created an efficient queuing system for the builders, we were able make this run like clockwork. In under two weeks, it was complete! Read ALL about the first build run drama on my blog.

ALL the cloud Pis

Improving piwheels

We analysed the failures, made some tweaks, installed some key dependencies, and ran the build again to raise our success rate from 76% to 83%. We also rebuilt packages for Python 3.5 (the new default in Raspbian Stretch). The wheels we build are tagged ‘armv7l’, but because our Raspbian image is compatible with all Pi models, they’re really ARMv6, so they’re compatible with Pi 3, Pi 2, Pi 1 and Pi Zero. This means the ‘armv6l’-tagged wheels we provide are really just the ARMv7 wheels renamed.

The wonderful piwheels monitor interface created by Dave

Now, you might be thinking “Why didn’t you just cross-compile?” I really wanted to have full compatibility, and building natively on Pis seemed to be the best way to achieve that. I had easy access to the Pis, and it really didn’t take all that long. Plus, you know, I wanted to eat my own dog food.

You might also be thinking “Why don’t you just apt install python3-numpy?” It’s true that some Python packages are distributed via the Raspbian/Debian archives too. However, if you’re in a virtual environment, or you need a more recent version than the one packaged for Debian, you need pip.

How it works

Now that the piwheels package repository is running as a service, hosted on a Pi 3 in the Mythic Beasts data centre in London. The pip package in Raspbian Stretch is configured to use piwheels as an additional index, so it falls back to PyPI if we’re missing a package. Just run sudo apt upgrade to get the configuration change. You’ll find that pip installs are much faster now! If you want to use piwheels on Raspbian Jessie, that’s possible too — find the instructions in our FAQs. And now, every time you pip install something, your files come from a web server running on a Raspberry Pi (that capable little machine)!

Try it for yourself in a virtual environment:
```
sudo apt install virtualenv python3-virtualenv -y
virtualenv -p /usr/bin/python3 testpip
source testpip/bin/activate
pip install numpy
```
This takes about 20 minutes on a Pi 3, 2.5 hours on a Pi 1, or just a few seconds on either if you use piwheels.

If you’re interested to see the details, try pip install numpy -v for verbose output. You’ll see that pip discovers two indexes to search:
```
2 location(s) to search for versions of numpy: * https://pypi.python.org/simple/numpy/ * https://www.piwheels.hostedpi.com/simple/numpy/
```
Then it searches both indexes for available files. From this list of files, it determines the latest version available. Next it looks for a Python version and architecture match, and then opts for a wheel over a source distribution. If a new package or version is released, piwheels will automatically pick it up and add it to the build queue.

How piwheels works

For the users unfamiliar with virtual environments I should mention that doing this isn’t a requirement — just an easy way of testing installations in a sandbox. Most pip usage will require sudo pip3 install {package}, which installs at a system level.

If you come across any issues with any packages from piwheels, please let us know in a GitHub issue.

Taking piwheels further

We currently provide over 670 000 wheels for more than 96 000 packages, all compiled natively on Raspberry Pi hardware. Moreover, we’ll keep building new packages as they are released.

Note that, at present, we have built wheels for Python 3.4 and 3.5 — we’re planning to add support for Python 3.6 and 2.7. The fact that piwheels is currently missing Python 2 wheels does not affect users: until we rebuild for Python 2, PyPI will be used as normal, it’ll just take longer than installing a Python 3 package for which we have a wheel. But remember, Python 2 end-of-life is less than three years away!

Many thanks to Dave Jones for his contributions to the project, and to Mythic Beasts for providing the excellent hosted Pi service.

Related/unrelated, check out my poster from the PyCon UK poster session:

Click to download the PDF!

Website: LINK
08/11/2017