Tag Archives: HackSpace

Build a xylophone-playing robot | HackSpace magazine #22

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/build-a-xylophone-playing-robot-hackspace-magazine-22/

HackSpace magazine issue 22 is out now, and our favourite tutorial this month will show you how to make this, a xylophone-playing robot!

Build a glockenspiel-playing robot with HackSpace magazine

Why spend years learning to play a musical instrument when you could program a robot to do it for you? This month HackSpace magazine, we show you how to build a glockenspiel-playing robot. Download the latest issue of HackSpace for free: http://rpf.io/hs22yt Follow HackSpace on Instagram: http://rpf.io/hsinstayt

If programming your own instrument-playing robot isn’t for you, never fear, for HackSpace magazine is packed full of other wonderful makes and ideas, such as:

  • A speaker built into an old wine barrel
  • Free-form LEDs
  • Binary knitwear
  • A Raspberry Pi–powered time machine
  • Mushroom lights
  • A…wait, hold on, did I just say a Raspberry Pi–powered time machine? Hold on…let me just download the FREE PDF and have a closer look. Page 14, a WW2 radio broadcast time machine built by Adam Clark. “I bought a very old, non-working valve radio, and replaced the internals with a Raspberry Pi Zero on a custom 3D-printed chassis.” NICE!


Honestly, this month’s HackSpace is so full of content that it would take me all day to go through everything. But, don’t take my word for it — try it yourself.

HackSpace magazine is out now, available in print from your local newsagent or from the Raspberry Pi Store in Cambridge, online from Raspberry Pi Press, or as a free PDF download. Click here to find out more and, while you’re at it, why not have a look at the subscription offers available, including the 12-month deal that comes with a free Adafruit Circuit Playground!

Author’s note

Yes, I know it’s a glockenspiel in the video.

The post Build a xylophone-playing robot | HackSpace magazine #22 appeared first on Raspberry Pi.

Monitor air quality with a Raspberry Pi

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/monitor-air-quality-with-a-raspberry-pi/

Add a sensor and some Python 3 to your Raspberry Pi to keep tabs on your local air pollution, in the project taken from Hackspace magazine issue 21.

Air is the very stuff we breathe. It’s about 78% nitrogen, 21% oxygen, and 1% argon, and then there’s the assorted ‘other’ bits and pieces – many of which have been spewed out by humans and our related machinery. Carbon dioxide is obviously an important polluter for climate change, but there are other bits we should be concerned about for our health, including particulate matter. This is just really small bits of stuff, like soot and smog. They’re grouped together based on their size – the most important, from a health perspective, are those that are smaller than 2.5 microns in width (known as PM2.5), and PM10, which are between 10 and 2.5 microns in width. This pollution is linked with respiratory illness, heart disease, and lung cancer.

Obviously, this is something that’s important to know about, but it’s something that – here in the UK – we have relatively little data on. While there are official sensors in most major towns and cities, the effects can be very localised around busy roads and trapped in valleys. How does the particular make-up of your area affect your air quality? We set out to monitor our environment to see how concerned we should be about our local air.

Getting started

We picked the SDS011 sensor for our project (see ‘Picking a sensor’ below for details on why). This sends output via a binary data format on a serial port. You can read this serial connection directly if you’re using a controller with a UART, but the sensors also usually come with a USB-to-serial connector, allowing you to plug it into any modern computer and read the data.

The USB-to-serial connector makes it easy to connect the sensor to a computer

The very simplest way of using this is to connect it to a computer. You can read the sensor values with software such as DustViewerSharp. If you’re just interested in reading data occasionally, this is a perfectly fine way of using the sensor, but we want a continuous monitoring station – and we didn’t want to leave our laptop in one place, running all the time. When it comes to small, low-power boards with USB ports, there’s one that always springs to mind – the Raspberry Pi.

First, you’ll need a Raspberry Pi (any version) that’s set up with the latest version of Raspbian, connected to your local network, and ideally with SSH enabled. If you’re unsure how to do this, there’s guidance on the Raspberry Pi website.

The wiring for this project is just about the simplest we’ll ever do: connect the SDS011 to the Raspberry Pi with the serial adapter, then plug the Raspberry Pi into a power source.

Before getting started on the code, we also need to set up a data repository. You can store your data wherever you like – on the SD card, or upload it to some cloud service. We’ve opted to upload it to Adafruit IO, an online service for storing data and making dashboards. You’ll need a free account, which you can sign up for on the Adafruit IO website – you’ll need to know your Adafruit username and Adafruit IO key in order to run the code below. If you’d rather use a different service, you’ll need to adjust the code to push your data there.

We’ll use Python 3 for our code, and we need two modules – one to read the data from the SDS011 and one to push it to Adafruit IO. You can install this by entering the following commands in a terminal:

pip3 install pyserial adafruit-io

You’ll now need to open a text editor and enter the following code:

This does a few things. First, it reads ten bytes of data over the serial port – exactly ten because that’s the format that the SDS011 sends data in – and sticks these data points together to form a list of bytes that we call data.

We’re interested in bytes 2 and 3 for PM2.5 and 4 and 5 for PM10. We convert these from bytes to integer numbers with the slightly confusing line:

pmtwofive = int.from_bytes(b’’.join(data[2:4]), byteorder=’little’) / 10

from_byte command takes a string of bytes and converts them into an integer. However, we don’t have a string of bytes, we have a list of two bytes, so we first need to convert this into a string. The b’’ creates an empty string of bytes. We then use the join method of this which takes a list and joins it together using this empty string as a separator. As the empty string contains nothing, this returns a byte string that just contains our two numbers. The byte_order flag is used to denote which way around the command should read the string. We divide the result by ten, because the SDS011 returns data in units of tens of grams per metre cubed and we want the result in that format aio.send is used to push data to Adafruit IO. The first command is the feed value you want the data to go to. We used kingswoodtwofive and kingswoodten, as the sensor is based in Kingswood. You might want to choose a more geographically relevant name. You can now run your sensor with:

python3 airquality.py

…assuming you called the Python file airquality.py
and it’s saved in the same directory the terminal’s in.

At this point, everything should work and you can set about running your sensor, but as one final point, let’s set it up to start automatically when you turn the Raspberry Pi on. Enter the command:

crontab -e

…and add this line to the file:

@reboot python3 /home/pi/airquality.py

With the code and electronic setup working, your sensor will need somewhere to live. If you want it outside, it’ll need a waterproof case (but include some way for air to get in). We used a Tupperware box with a hole cut in the bottom mounted on the wall, with a USB cable carrying power out via a window. How you do it, though, is up to you.

Now let’s democratise air quality data so we can make better decisions about the places we live.

Picking a sensor

There are a variety of particulate sensors on the market. We picked the SDS011 for a couple of reasons. Firstly, it’s cheap enough for many makers to be able to buy and build with. Secondly, it’s been reasonably well studied for accuracy. Both the hackAIR and InfluencAir projects have compared the readings from these sensors with more expensive, better-tested sensors, and the results have come back favourably. You can see more details at hsmag.cc/DiYPfg and hsmag.cc/Luhisr.

The one caveat is that the results are unreliable when the humidity is at the extremes (either very high or very low). The SDS011 is only rated to work up to 70% humidity. If you’re collecting data for a study, then you should discard any readings when the humidity is above this. HackAIR has a formula for attempting to correct for this, but it’s not reliable enough to neutralise the effect completely. See their website for more details: hsmag.cc/DhKaWZ.

Safe levels

Once you’re monitoring your PM2.5 data, what should you look out for? The World Health Organisation air quality guideline stipulates that PM2.5 not exceed 10 µg/m3 annual mean, or 25 µg/m3 24-hour mean; and that PM10 not exceed 20 µg/m3 annual mean, or 50 µg/m3 24-hour mean. However, even these might not be safe. In 2013, a large survey published in The Lancet “found a 7% increase in mortality with each 5 micrograms per cubic metre increase in particulate matter with a diameter of 2.5 micrometres (PM2.5).”

Where to locate your sensor

Standard advice for locating your sensor is that it should be outside and four metres above ground level. That’s good advice for general environmental monitoring; however, we’re not necessarily interested in general environmental monitoring – we’re interested in knowing what we’re breathing in.

Locating your monitor near your workbench will give you an idea of what you’re actually inhaling – useless for any environmental study, but useful if you spend a lot of time in there. We found, for example, that the glue gun produced huge amounts of PM2.5, and we’ll be far more careful with ventilation when using this tool in the future.

Adafruit IO

You can use any data platform you like. We chose Adafruit IO because it’s easy to use, lets you share visualisations (in the form of dashboards) with others, and connects with IFTTT to perform actions based on values (ours tweets when the air pollution is above legal limits).

One thing to be aware of is that Adafruit IO only holds data for 30 days (on the free tier at least). If you want historical data, you’ll need to sign up for the Plus option (which stores data for 60 days), or use an alternative storage method. You can use multiple data stores if you like.

Checking accuracy

Now you’ve got your monitoring station up and running, how do you know that it’s running properly? Perhaps there’s an issue with the sensor, or perhaps there’s a problem with the code. The easiest method of calibration is to test it against an accurate sensor, and most cities here in the UK have monitoring stations as part of Defra’s Automatic Urban and Rural Monitoring Network. You can find your local station here. Many other countries have equivalent public networks. Unless there is no other option, we would caution against using crowdsourced data for calibration, as these sensors aren’t themselves calibrated.

With a USB battery pack, you can head to your local monitoring point and see if your monitor is getting similar results to the monitoring network.

HackSpace magazine #21 is out now

You can read the rest of this feature in HackSpace magazine issue 21, out today in Tesco, WHSmith, and all good independent UK newsagents.

Or you can buy HackSpace mag directly from us — worldwide delivery is available. And if you’d like to own a handy digital version of the magazine, you can also download a free PDF.

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Steampunk-inspired Raspberry Pi enclosure | HackSpace magazine #20

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/steampunk-inspired-raspberry-pi-enclosure-hackspace-magazine-20/

Who doesn’t like a good-looking case for their Raspberry Pi?

Exactly.

We’ve seen many homemade cases over the years, from 3D-printed enclosures to LEGO, Altoid tins and gravity-defying Zelda-themed wonderments. We love them all as much as we love own — our own case being this one if you fancy one — and always look forward to seeing more.

Cue this rather fancy steampunk-inspired enclosure made by Erich Styger, as featured in the latest issue of HackSpace magazine.

The magazine states:

This steampunk enclosure for the Raspberry Pi by Erich Styger was laser-cut out of 4 mm birch plywood, and stained to make it look a bit more 1890s. It’s built to fit a Raspberry Pi with an NXP tinyK22 board and a battery backup, and there are ports artfully crafted into it so that the system is fully functional even when the box is closed.

Those gears aren’t just for show: turn the central wheel on the front of the box to open the enclosure and get access to the electronics inside.



Cool, right?

What cases have you made for your Raspberry Pi? Let us know in the comments, or by tagging @Raspberry_Pi and @HackSpaceMag on Twitter.

HackSpace magazine is out now

You can read the rest of this feature in HackSpace magazine issue 20, out today in Tesco, WHSmith, and all good independent UK newsagents.

Or you can buy HackSpace mag directly from us — worldwide delivery is available. And if you’d like to own a handy digital version of the magazine, you can also download a free PDF.

The post Steampunk-inspired Raspberry Pi enclosure | HackSpace magazine #20 appeared first on Raspberry Pi.

Liverpool MakeFest | HackSpace magazine #19

Post Syndicated from Ben Everard original https://www.raspberrypi.org/blog/liverpool-makefest-hackspace-magazine-19/

The news that UK Maker Faire was to shut its doors came as a bit of a surprise to many. This vibrant weekend of makers meeting, sharing, and learning was absolutely brilliant, and left us fizzing with ideas after our visits there. We’re sad that it’s gone.

Makers being makers though, if there’s demand, it will be filled. And that’s exactly what’s happening in Liverpool with Liverpool MakeFest. On 29 June 2019, the MakeFest will hold its fifth iteration. This is the UK’s biggest free maker event, attracting thousands of visitors, and its vision of a free, maker-focused festival is spreading far and wide.

We visited the mid-Victorian splendour of Liverpool Central Library, the home of MakeFest, to talk to the founders — Denise Jones, Mark Feltham, and Caroline Keep — to find out what makes this event special.

Liverpool MakeFest 2019 is taking place at the Central Library, Saturday 29 June 2019, and it’s completely free to attend

HackSpace magazine: Hello! Thanks for having us over here. How did the three of you come together to start Liverpool MakeFest?

Caroline Keep: I was a geotechnical engineer, Mark’s an academic, and Denise is a librarian. We bumped into each other watching a workshop in lantern making. Mark had all the academic experience. When I came to work with Mark on his makerspace, I was the geeky maker — he didn’t even have a smartphone at that time. I got the education bug and then moved into secondary school teaching.

Mark Feltham: It all started over there, as a chance meeting. We bumped into each other and got chatting. Within six weeks, we’d filled the library. We thought it would be a one-off, but since then it’s taken off.

Caroline is the reigning TES New Teacher Of The Year

HS: So no business plan, no franchising fees, no world domination?

CK: We’ve just winged it. We made all the banners, bunting. The first year my PGCE fund paid for MakeFest! This building reopened again in 2013, and in 2014 we were lucky that they were running a programme of events and initiatives to make it a really vibrant building, so it was the right time as well. We thought we’d have a little room off to the side and get maybe six tables. We’d already done a Mini Maker Faire, and we’ve always been good friends with [local makerspace] DoES Liverpool, so we were confident we’d get at least a few people turning up. And in six weeks we were full.

MF: We pulled the first one off, we’re talking the first three floors of the library and 60 makers, for £850. And that included feeding them and making badges as well.

One of the spin-offs that have come out of MakeFest is Little Sandboxes, which takes making out to deprived areas of the city

HS: For context, this building is huge. It’s bigger than most libraries; it’s probably about the same size as the Life Centre in Newcastle, where UK Maker Faire was held until recently. It must have helped to have a librarian on board to negotiate with the powers that be?

Denise Jones: I had to sell it to the people in charge back then, which were the head of service and the manager of this building. The Department for Culture, Media and Sport has a Taskforce for Libraries, which is funded until next year. We’re close to finishing the national guidance now for the Taskforce — the idea is to get one of these [MakeFests] in every library. We wanted the guidance doc to be inclusive of museums and libraries, because we knew that Manchester had opted to put their MakeFest in a museum. We’ve got Chester and Stoke MakeFest, and there’s one in the pipeline in Wrexham. We were having the same conversations over and over again, so we decided to write a document: how to run a MakeFest.

Liverpool Central Library was renovated a few years ago — the precious books went into temporary storage in a salt mine in Cheshire to keep them dry

HS: What have we got to look forward to this year and beyond?

CK: That’s a good question. We’ve got some corking stuff coming this year. We’ve given it the theme ’Space and time – creativity in the making’. We’ve got events planned for the Apollo anniversary, and [just] before MakeFest we’re going to kick off with a music day, showing people how to make music, and making the instruments to make music. That’s another spin-off that’s come out of MakeFest: the MakerNoise Unconference at Edge Hill University.

MF: We’ve always felt that we hold MakeFest in trust for makers. In terms of where it goes long-term, I don’t see it ever becoming more than a one-day event here, because one day is good. It gives people Sunday to get over things, and get home because they have day jobs on a Monday. We’re always very sensitive to that, we don’t want to take up too much of people’s time. The other thing is that I don’t see it spilling out into a bigger building; it’s always going to be in the library. But the way to grow it is to put it in other libraries. Not to make this one, Liverpool, bigger and take over. Then each maker community gets its own feel, and its own vibe — Stoke MakeFest has a very different feel to ours, because their maker scene is different to ours, and their city is different to ours.

The other way to expand it is that, rather than by just expanding to other cities, you can have more events on throughout the year. Rather than being solely a one-day event, you can have all these spin-offs, so once a month there’s something going on. Rather than it just being about tech and digital, we’ve always liked to have some sort of fantasy element. Things like Doctor Who, Star Wars, Darth Vader, K-9 — the kids love that. We have a lot of friends who are into steampunk; they get roped in to do front-of-house duties. You know what the funny thing was at the first one? Not only did the public enjoy it, but also the makers. It’s kind of like a musician playing an acoustic set. We’ve got a get-together on the Thursday before, we’ve got a Friday night party going, we always do an after-party. The public come on the Saturday, but there’s always stuff going on that week for makers.

In addition to always wanting it to be free for the public, and for the makers to not have to pay for their stand, we feel very strongly that we should give something back. We always give them lunch, we always give them a badge, and there’s always a party. We can’t pay them, but it’s our way of showing our appreciation to the makers who come and make it what it is. The celebration and sharing are big parts of the maker ethos.

People like to show [their projects] not to show off, not to say ‘Look at how clever I am’ — it’s more to say ‘Look at this awesome thing, isn’t this cool?’ Trying to explain that to people can be tricky. You can make this: here’s how you do it. That’s the ethos.

CK: I always feel with MakeFest — you said it’s like an acoustic gig. I always envisioned it as Liverpool’s party for makers. It’s our little get-together, and that’s how I like it.

Read the full interview in HackSpace magazine issue 19, out now! This month we’re looking at building a walking robot, laser cutting LED jewellery, the 55 timer chip, and much more. Download the issue for free, or buy it in print on our website.

Get HackSpace magazine issue 19 from all good newsagents

Special subscription offer

To have 132 pages of making delivered to your doorstep every month, subscribe to HackSpace magazine from just £5 for your first three issues.

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Raspberry Pi Press: what’s on our newsstand?

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/raspberry-pi-press-newsstand/

Raspberry Pi Press, the publishing branch of Raspberry Pi Trading, produces a great many magazines and books every month. And in keeping with our mission to make computing and digital making as accessible as possible to everyone across the globe, we make the vast majority of our publications available as free PDFs from the day we release new print versions.

We recently welcomed Custom PC to the Press family and we’ve just published the new-look Custom PC 190. So this is a perfect time to showcase the full catalogue of Raspberry Pi Press publications, to help you get the most out of what we have on offer.

The MagPi magazine

The MagPi was originally created by a group of Raspberry Pi enthusiasts from the Raspberry Pi forum who wanted to make a magazine that the whole community could enjoy. Packed full of Pi-based projects and tutorials, and Pi-themed news and reviews, The MagPi now sits proudly upon the shelves of Raspberry Pi Press as the official Raspberry Pi magazine.

The MagPi magazine issue 81

Visit The MagPi magazine online, and be sure to follow them on Twitter and subscribe to their YouTube channel.

HackSpace magazine

The maker movement is growing and growing as ever more people take to sheds and makerspaces to hone their skills in woodworking, blacksmithing, crafting, and other creative techniques. HackSpace magazine brings together the incredible builds of makers across the world with how-to guides, tips and advice — and some utterly gorgeous photography.

Visit the HackSpace magazine website, and follow their Twitter account and Instagram account.

Wireframe magazine

“Lifting the lid on video games”, Wireframe is a gaming magazine with a difference. Released bi-weekly, Wireframe reveals to readers the inner workings of the video game industry. Have you ever wanted to create your own video game? Wireframe also walks you through how you can do it, in their ‘The Toolbox’ section, which features tutorials from some of the best devs in the business.

Follow Wireframe magazine on Twitter, and learn more on their website.

Hello World magazine

Hello World is our free magazine for educators who teach computing and digital making, and we produce it in association with Computing at Schools and the BCS Academy of Computing. Full of lesson plans and features from teachers in the field, Hello World is a unique resource for everyone looking to bring computing into the classroom, and for anyone interested in computing and digital making education.

Hello World issue 8

Educators in the UK can subscribe to have Hello World delivered for free to their door; if you’re based somewhere else, you can download the magazine for free from the day of publication, or purchase it via the Raspberry Pi Press online store. Follow Hello World on Twitter and visit the website for more.

Custom PC magazine

New to Raspberry Pi Press, Custom PC is the UK’s best-selling magazine for PC hardware, overclocking, gaming, and modding. With monthly in-depth reviews, special features, and step-by-step guides, Custom PC is the go-to resource for turning your computer up to 11.

Visit the shiny new Custom PC website, and be sure to follow them on Twitter.

Books

Magazines aren’t our only jam: Raspberry Pi Press also publishes a wide variety of books, from introductions to topics like the C programming language and Minecraft on your Pi, to our brand-new Raspberry Pi Beginner’s Guide and the Code Club Book of Scratch.

An Introduction to C and GUI programming by Simon Long


We also bridge the gap between our publications with one-off book/magazine hybrids, such as HackSpace magazine’s Book of Making and Wearable Tech Projects, and The MagPi’s Raspberry Pi Projects Book series.



Getting your copies

If you’d like to support our educational mission at the Raspberry Pi Foundation, you can subscribe to our magazines, and you can purchase copies of all our publications via the Raspberry Pi Press website, from many high street newsagents, or from the Raspberry Pi Store in Cambridge. And most of our publications are available as free PDFs so you can get your hands on our magazines and books instantly.

Whichever of our publications you choose to read, and however you choose to read them, we’d love to hear what you think of our Raspberry Pi Press offerings, and we hope you enjoy them all.

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Create wearable tech with Sophy Wong and our new book | HackSpace magazine issue 18

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/create-wearable-tech-projects-with-sophy-wong/

Forget Apple Watch and Fitbit — if we’re going to wear something electronic, we want to make it ourselves!

Wearable Tech Projects, from the makers of HackSpace magazine, is a 164-page book packed with projects for the fashionable electronics enthusiast, with more than 30 projects which will blink, flash, and spark joy in your life.

Sophy Wong HackSpace Wearable Tech Projects book

Make a wearable game controller

Fans of Sophy Wong will already know about the amazing wearable tech that she develops. We wanted to make sure that more people discovered her work and the incredible world of wearable technology. You’ll start simple with sewable circuits and LEDs, and work all the way up to building your own wearable controller (complete with feathers) for an interactive, fully immersive game of Flappy Bird.

Sophy Wong HackSpace Wearable Tech Projects book

Pick up the tricks of the trade

Along the way, you’ll embed NFC data in a pair of cufflinks, laser cut jewellery, 3D print LED diffusers onto fabric for a cyberpunk leather jacket, and lots more.

 

Sophy Wong HackSpace Wearable Tech Projects book

Learn new techniques from Sophy Wong

You’ll discover new techniques for working with fabric, find out about the best microcontrollers for your projects, and learn the basics of CircuitPython, the language developed at Adafruit for physical computing. There’s no ‘Hello, World!’ or computer theory here; this is all about practical results and making unique, fascinating things to wear.

Get your copy today

Wearable Tech Projects is available to buy online for £10 with free delivery. You can also get it from WHSmith and all the usual high street retail suspects.


And that’s not all. There is also a new issue of HackSpace magazine out now, with an awesome special feature on space! You can find your copy at the same retailers as above. You can also download both Issue 18 and the Wearables book for free from the HackSpace website.

 

The post Create wearable tech with Sophy Wong and our new book | HackSpace magazine issue 18 appeared first on Raspberry Pi.

Build a SatNOGS ground station with a Raspberry Pi 3B+ | HackSpace magazine #18

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/build-a-satnogs-ground-station-raspberry-pi-3b-hackspace-magazine-18/

The big feature on outer space in issue 18 of HackSpace magazine, available from today, shows you how to build your own satellite and launch it into orbit.

No, we’re not kidding, this is an actual thing you can do.

And to track the satellite you’ve launched, or another satellite you’re interested in, here’s how to build your own SatNOGS ground station with a Raspberry Pi 3B+.

Building a Raspberry Pi ground station

Once you’ve built and launched your small satellite, you’ll want to listen to all the glorious telemetry and data it‘s sending back as it hurtles around the Earth. Or perhaps you aspire to have a satellite up there, but in the meantime you want to listen to some other objects? What you need is a ground station, but a single ground station has one slight flaw. Most of the time a satellite will not be overhead of a single ground station; in fact, it may only pass over a ground station once every few days, massively reducing the amount of information or data we can receive. So we need a network of ground stations. The SatNOGS network solves this by creating a global network of stations that can work together to increase coverage.

SatNOGS is an open-source project that has numerous designs for satellite ground stations, but whichever design you pick, you can join the network that links them all via the web.

A station owner can use the website to browse for future passes of a satellite, and then click a button to schedule for their station to turn on, tune to frequency, and record the pass, sometimes even rotating the antenna on the station to track the satellite. Not only can a station owner schedule an observation on their own station, but they can schedule observations on any station on the global network.

As we can see from this map of data being collected of a recent SSTV broadcast from the ISS (sends single-frame images transmitted via audio from the ISS), the SatNOGS network has near-global coverage, rivalling most professional institutions in the world.

Simple setup

The simplest form of a SatNOGS station is one that doesn’t move or track and is made from a static antenna, a Raspberry Pi, and a cheap software-defined radio (SDR) dongle. The SDR dongle has become ubiquitous in maker circles as it is an affordable entry item into the world of receiving signals via SDR. Looking at our ingredients in the image below, let’s explore them a little more before we get started.

While a permanent station may do better connected by Ethernet cable, using the Raspberry Pi’s built-in wireless LAN functionality means we can run this simply with only a power cable. While many have used the cheapest Realtek SDR dongles with success, some people have found the slightly more refined versions can be more stable – a current recommendation is the RTL-SDR V3, which has a better casing for thermal dissipation, and slightly upgraded components. The RTL-SDR V3 is available here.

The classic antenna recommended for a static SatNOGS setup shown above is a ‘turnstile’ antenna; commercial models are available, such as the Wimo TA-1, but people have designed and built lots of different static antennas for different frequencies and with small budgets – check out the tutorial Make a Slim Jim antenna on page 112 (in HackSpace issue 18, links below).

In order to set up a ground station, one of the first tasks we need to do is set up an account on network.satnogs.org. Registering on the site then gives us a dashboard where we can begin to set up a station. Click to add a station — we then need to supply it with some basic details as per the image below: a name for the station, a location in latitude and longitude (Google is your friend here!), and the elevation of the station above sea-level.

You need to decide what frequency your station is going to cover; the most common ranges are UHF and VHF, which would require different antennas, but either range has a huge number of objects you can schedule to observe. Many people opt for VHF, as this includes the frequency range for a lot of the different transmissions from the ISS, so we are going to choose VHF as well. You also need to add a minimum elevation value — this is the minimum angle that a satellite must be in terms of height for your station to see it — if you aren’t sure, either ask for help on the forums, or leave it for now at the default 10 degrees.

Having filled in the boxes to create the station (leave the ‘this is in testing’ box ticked for now), you should now see a ground station entry has been made on your account, as above. You will see (even though it isn’t set up yet) a list populating underneath the entry with ‘Pass Predictions’, which are things you could schedule to observe once you are up and running. Before we leave the website, we need to make a note of the number assigned to the ground station, and also our own personal API key — which we can find in our dashboard by clicking the API key button. These two pieces of information are what will ultimately connect our ground station hardware to the website account.

The next task is to sort out the Raspberry Pi. You can find the current custom SatNOGS image here.

Flash this to your microSD card as you would for a regular Raspberry Pi setup — the free app Etcher, for example, is a simple tool that allows you to flash an image to a card.

Once done, boot the Raspberry Pi, and you can either SSH into the Pi, or connect a keyboard and monitor and interact with the setup that way. The first things we need to do are not SatNOGS-specific, but are the usual things we do when setting up a Raspberry Pi. We need to set up a different password by running the sudo raspi‐config command. Once you’ve set a password and expanded the file system, it’s also useful to set the time zone to UTC, as this is used throughout the SatNOGS network. If you want to run this test station wirelessly, then you need to configure your network connection at this point. If you are connecting via an Ethernet cable, then you don’t need to do anything else. Apply the changes and reboot (then see ‘Final setup’ box above in HackSpace issue 18, links below).

Now, if we go back to our dashboard on the SatNOGS website (perhaps wait a few minutes and click Refresh), we should see that the station is now online, as above. We should see an orange spot on the network map showing our proud station in testing. Being in testing means that only you can schedule observations on the station, but when you are ready, you can change settings to take it out of testing and then it is fully on the network.

On the hunt

Power down one last time and connect the RTL-SDR dongle and the antenna, then reboot — you are now ready to hunt satellites! Scheduling observations is as simple as selecting passes from the list and clicking Schedule. There may be drop-down choices for different transmitters to listen for on the same satellite, and other choices, but essentially you click Calculate to create the observation and then Schedule for the job to be created and sent to the queue for your station. There are hundreds of satellites to try to observe, so don’t worry if you don’t understand what any of them are — in the pass predictions list, if you click the name of a satellite you will get a pop-up with information about it. For a more detailed walkthrough of scheduling an observation on the SatNOGS network, check out this blog post.

After the time of the pass, return to the observation page and, hopefully, you should see some signals. Don’t worry if your first few observations aren’t successful: try at least a dozen observations before making any changes, as there are many possible reasons for a signal not getting picked up; indeed, the satellite may not even have been transmitting. If you have received a signal, you should ‘vet’ the observation as good; this is particularly important if you have scheduled on someone else’s station – etiquette says we should check and vet our own observations. Check out the Slim Jim antenna (see page 112 of HackSpace magazine issue 18, links below) for a link to a successful observation you can listen to.

Happy satellite hunting!

Finally, it’s a great idea to join the Libre Space Foundation community forum (or IRC), as it hosts the SatNOGS community channels, and there is a wealth of expertise and help available there from a very welcoming community. If you build a station, go and share your achievement on the forum — everyone will be pleased to see it.

Get HackSpace magazine issue 18 — out today

HackSpace magazine issue 18 is out today, and available online, or from many high-street retailers such as WHSmith and Sainsbury’s in the UK, and Barnes & Nobel in the US.

You can also download issue 18 for free, today as a PDF, so there really is no reason not to give HackSpace a spin.

The post Build a SatNOGS ground station with a Raspberry Pi 3B+ | HackSpace magazine #18 appeared first on Raspberry Pi.

The future of 3D printing with Dr Adrian Bowyer | HackSpace magazine #17

Post Syndicated from Ben Everard original https://www.raspberrypi.org/blog/future-3d-printing-adrian-bowyer-hackspace-17/

You might have heard of RepRap. It’s the project that began at the University of Bath in 2005 with the aim of creating a self-replicating, open-source 3D printer. As is the nature of open source, many other projects have spun off from RepRap, including the Prusa i3. Without RepRap, the field of 3D printing would be much smaller, less advanced, and a lot less open.

Adrian was made an MBE in the New Year Honours list, for services to 3D printing.

We drove many miles through wind and rain to meet Dr Adrian Bowyer, co-founder of the RepRap project who now, along with his daughter Sally, runs RepRap Ltd. The two of them are still pushing boundaries, raising standards, and lowering prices, so we sat down to talk about RepRap and where the 3D printing industry is heading.

It may be an obvious question, but why did you start the RepRap project?

Adrian Bowyer: Curiosity. I have always been interested in the idea of self-replicating machines ever since I was a child. When my university acquired some commercial 3D printers, as soon as they arrived I thought, ah, we’ve got a technology here that is sufficiently versatile that it stands a chance of being able to copy itself. Having had that idea, the very next question that occurs to your brain is: will this work? And that was the genesis of the project. I wanted to find out if we could make a machine that could print a significant fraction of its own parts and self-replicate.

It was literally the case that, at the height of development of RepRap in Bath 2008/2009, I was effectively running, in terms of numbers of staff, the biggest research project in any UK university. I wasn’t paying any of them of course, and they were distributed all over the world, but if you counted them up, there were more of them working with me than were working in any other single research project in any other university in the UK.

What are you doing with RepRap at the moment?

AB: We’re looking at distributed processor RepRaps, so instead of having a single CPU, we put a single CPU on each device in the machine, such as the heaters, the motors, and so on. This isn’t a new idea; other people have tried this in the past. From the perspective of Raspberry Pi, that’s interesting because such a machine wouldn’t need real-time response from the processor that’s at the heart of the machine.

If you’ve got a Linux system running on something, it’s not great for real-time control, because of interrupts. Whereas the sort of system we’re working on would have a Raspberry Pi in the middle, with a load of Arduinos around it. You can hand over the hardware timing to the Arduino, which, being dedicated, can be guaranteed to generate a poll every 20 microseconds or whatever it is. Whereas the thing sitting in the middle, doing the control, just has to be able to respond every few milliseconds. That’s something we’re putting together with Raspberry Pis and Arduinos.

Each Arduino is monitoring and controlling one aspect of the printer

One of the reasons that we want to do it is that we’re looking at making larger machines, and also a machine that not only is a 3D printer, but also incorporates a plasma cutter. Now, the thing about a plasma cutter is that it generates an enormous amount of electronic noise. You get lots of interference from it. So the ideal way to send electrical signals around the machine is not using electricity, but optics. So what we would be doing would be setting up a machine with optical communication between each of its component parts and the controller, so that electrical interference isn’t a problem, and, in order to do that [the system] has to be distributed in the way that I’ve just described.

Where, in general, do you think 3D printing is heading?

AB: The analogy I often draw is with washing clothes, which went through three stages: it started off with us washing our own clothes. In the scullery or the kitchen, you’d wash your clothes once a week. And then in Victorian times, as economies of scale kicked in, there would be a town laundry, where you would send your clothes and they’d come back clean. But now we have a robot in the kitchen that can wash our clothes. It’s come back to us, this time automated.

Making stuff in general, it seems to me, is going through that progression, just 100 years later. It started off that, if you needed a gate hinge, you went to the blacksmith in your village. He would make you a gate hinge. Now if you want a gate hinge, you go to the shop and buy one, and it was made halfway around the world. But if we bring some of that back into our cities, it’s like bringing our washing back from the town laundry into our homes. As long as it’s automated: the rule seems to be that if something is automatable so that people don’t have to pay a lot of attention, and it’s low-cost enough, people can take it back to themselves, and economies of scale get reversed.

This ukulele was printed in two parts. It’s playable, and sounds great.

Finally, congratulations on your MBE!

AB: That’s very kind! The certificate is an impressive thing. Signed by Her Majesty the Queen, and by Prince Philip as the person who is in charge of knighthoods and such.

I’m going up in May to Buckingham Palace to have it pinned on my chest, so that’ll be interesting. The commendation says: “Inventor: for services to 3D printing.” Short and to the point.

Read more

The full interview is in HackSpace magazine issue 17, where we also help you develop your Arduino skill, look at an open-source lathe, design a PCB in KiCad, build a polyphonic synthesizer, and much more.

Buy your copy now from the Raspberry Pi Press store, major newsagents in the UK, or Barnes & Noble, Fry’s, or Micro Center in the US. Or, download your free PDF copy from the HackSpace magazine website.

Never miss an issue

Subscribe today and get three issues for just £5 (in the UK — additional postage charges apply elsewhere)!

The post The future of 3D printing with Dr Adrian Bowyer | HackSpace magazine #17 appeared first on Raspberry Pi.

Make art with LEDs | HackSpace magazine #16

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/make-art-with-leds-hackspace-16/

Create something beautiful with silicon, electricity, your endless imagination, and HackSpace magazine issue 16 — out today!

HackSpace magazine 16

LEDs are awesome

Basically, LEDs are components that convert electrical power into light. Connect them to a power source (with some form of current limiter) in the right orientation, and they’ll glow.

Each LED has a single colour. Fortunately, manufacturers can pack three LEDs (red, green, and blue) into a single component, and varying the power to each LED-within-an-LED produces a wide range of hues. However, by itself, this type of colourful LED is a little tricky to control: each requires three inputs, so a simple 10×10 matrix would require 300 inputs. But there’s a particular trick electronics manufacturers have that make RGB LEDs easy to use: making the LEDs addressable!

An RGB LED

Look: you can clearly see the red, green, and blue elements of this RGB LED

Addressable LEDs

Addressable LEDs have microcontrollers built into them. These aren’t powerful, programmable microcontrollers, they’re just able to handle a simple communications protocol. There are quite a few different types of addressable LEDs, but two are most popular with makers: WS2812 (often called NeoPixels) and APA102 (often called DotStars). Both are widely available from maker stores and direct-from-China websites. NeoPixels use a single data line, while DotStars use a signal and a clock line. Both, however, are chainable. This means that you connect one (for NeoPixels) or two (for DotStars) pins of your microcontroller to the Data In connectors on the first LED, then the output of this LED to the input of the next, and so on.

Exactly how many LEDs you can chain together depends on a few different things, including the power of the microcontroller and the intended refresh rate. Often, though, the limiting factor for most hobbyists is the amount of electricity you need.

Which type to use

The big difference between NeoPixels and DotStars comes down to the speed of them. LEDs are made dimmer by turning them off and on very quickly. The proportion of the time they’re off, the dimmer they are. This is known as pulse-width modulation (PWM). The speed at which this blinking on and off can have implications for some makes, such as when the LEDs are moving quickly.

NeoPixels

  • Cheap
  • Slowish refresh rate
  • Slowish PWM rate

DotStars

  • More expensive
  • Faster refresh rate
  • Fast PWM rate
NeoPixels moving in the dark

As a NeoPixel is moved through a long-exposure photograph, you can see it blink on and off. DotStars – which have a faster PWM rate – avoid this.

Safety first!

HackSpace magazine’s LED feature is just a whistle-stop guide to the basics of powering LEDs — it’s not a comprehensive guide to all things power-related. Once you go above a few amperes, you need to think about what you’re doing with power. Once you start to approach double figures, you need to make sure you know what you’re doing and, if you find yourself shopping for an industrial power supply, then you really need to make sure you know how to use it safely.

Read more

Read the rest of the exclusive 14-page LED special in HackSpace magazine issue 16, out today. Buy your copy now from the Raspberry Pi Press store, major newsagents in the UK, or Barnes & Noble, Fry’s, or Micro Center in the US. Or, download your free PDF copy from the HackSpace magazine website.

HackSpace magazine 16 Front Cover

We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine.

Subscribe now

Subscribe to HackSpace on a monthly, quarterly, or twelve-month basis to save money against newsstand prices.

Twelve-month print subscribers get a free Adafruit Circuit Playground Express, loaded with inputs and sensors and ready for your next project. Tempted?

The post Make art with LEDs | HackSpace magazine #16 appeared first on Raspberry Pi.

The explosive inventions of Colin Furze

Post Syndicated from Ben Everard original https://www.raspberrypi.org/blog/colin-furze-hackspace-mag-15/

In January 2007, one plumber and a few friends in a pub set out to build a wall of death out of 850 pallets in a field in Lincolnshire. It’s something we’ve all done as children on a small scale, jumping over a cardboard box perhaps. But to scale it up to something 30ft in diameter and 17ft high, and ride around it on a moped at 25mph… that took a special kind of person. That took maker, inventor, YouTuber, and record-breaker extraordinaire Colin Furze.

Colin Furze

You’ve probably seen one or two of Colin Furze’s videos on YouTube. There’s the one where he shoots flames out of a scooter (gaining the attention of Her Majesty’s Lincolnshire Constabulary). There’s the one where he builds the world’s fastest mobility scooter, and the one where he sets off 5000 fireworks at once to celebrate getting three million YouTube subscribers. Maybe you know the one where he sets himself on fire, or the one with a spinning belt of knives to make chopping vegetables easier.

We had a chat with Colin, and sent a very brave photographer to his house to get some photos of him from a safe distance. If you don’t know him, strap in: over the coming pages you’re going to get an exclusive insight into the world of Britain’s most explosive maker.

How to be a better maker, the Furze way

“The thing that I find most exciting about what I do is that sometimes you have the initial test. You have an idea, you nip out to the shed – this could be after tea at night – and you bodge something together quite crudely. And you get that moment of realisation that it might actually work. I think that’s what I find the most enjoyable.”

“I’ve got to the point now where I’ve set my bar pretty high in terms of what people expect. Some projects, like the belt of knives, I knocked that up pretty quick because it was quite simple, but there were other things like the turbo jet scooter, I made sure things look good and they’re pretty well made, so they can take quite a while.”

“Some are a lot easier than others to make, and if you look through my videos in order, they tend to go from ones that are a bit more complicated to ones that are simple. You can never really predict what you’re going to get next; with some YouTube channels it’s much of the same thing if you know what I mean. When I upload a video, you’ve no idea what it’s going to be. I try to hop around a bit so it doesn’t become the same thing over and over again.”

Quality, not quantity

“I used to get a video up every week, or at least try for that, whereas now I’m going to kill myself if I try to match that. I’ve come to the conclusion that they’re ready when they’re ready. If there’s no video on a Thursday, the world’s not going to end. And it makes them a little bit more special when they do come out.”

“I’ve never worked in an office. I think I’d enjoy it for a week, then I’d drive everyone up the wall. I’d be too noisy I think. The only thing I miss from plumbing is the social aspect, because obviously I don’t see many people being in the shed, because I’m only just outside the back door of my house. I haven’t even got a commute. You can just be in there beavering away. I only ever have Rick in there with me when it’s a two-person job. And also it’s not like I’ve got two sheds so something can be being built in the background… a lot of people, when they get to six or seven million subscribers, employ loads of staff, the workshop gets bigger, everything expands, and you start to look at it and think ‘What is this now?’ This is not a guy in the shed at the side of his house trying to make impossible stuff; it’s a factory. Well, you’d expect big stuff to come out of a factory, wouldn’t you? Whereas when I make stuff in that little shed, there’s a little bit of extra interest in it because it’s something that most people could own, if they’ve got the space. So I’ve purposely kept it small and not got too big.”

“I like to go into something thinking ‘Let’s make the best job I can of this.’ Like the shredder that I’ve just made, all the housing and the aluminium surround, I wanted to get it as precise at possible. I used my optical punch and tried to get everything bang on. It all bolts together, and it looks like something that if I’d been shown it before, I’d have gone ‘No, I’m not sure I could make that.’”

Read more!

Read the rest of the exclusive 12-page Colin Furze special in HackSpace magazine issue 15, out today. Buy your copy now from the Raspberry Pi Press store, major newsagents in the UK, or Barnes & Noble, Fry’s, or Micro Center in the US. Or, download your free PDF copy from the HackSpace magazine website.

Front cover of HackSpace magazine issue 15

We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine.

Subscribe now

Subscribe to HackSpace on a monthly, quarterly, or twelve-month basis to save money against newsstand prices.

Twelve-month print subscribers get a free Adafruit Circuit Playground Express, loaded with inputs and sensors and ready for your next project. Tempted?

The post The explosive inventions of Colin Furze appeared first on Raspberry Pi.

From HackSpace mag issue 14: DIY Geiger counters

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/from-hackspace-mag-issue-14-diy-geiger-counters/

In HackSpace magazine issue 14, out today, Cameron Norris writes about how citizen scientists at Tokyo Hackerspace took on the Fukushima nuclear disaster.

Safecast is an independent citizen science project that emerged in the wake of the Fukushima nuclear disaster to provide accurate, unbiased, and credible data on radiation exposure in Japan.

On 11 March 2011, an undersea earthquake off the Pacific coast of Thoku, Japan, caused the second-worst nuclear accident in the history of nuclear power generation, releasing almost 30% more radiation than the Chernobyl disaster in 1986.

The magnitude 9.0–9.1 earthquake resulted in a series of devastating tsunami waves that damaged the backup generator of Fukushima Daiichi Nuclear Power Plant. Without functioning cooling systems, the temperature of the plant’s many nuclear reactors steadily began to rise, eventually leading to a partial meltdown and several hydrogen gas explosions, launching nuclear fallout into the air and sea. Due to concerns over possible radiation exposure, the Japanese government established an 18-mile no-fly zone around the Fukushima plant, and approximately 232 square miles of land was evacuated.

However, citizens of Fukushima Prefecture living outside of the exclusion zone were faced with a serious problem: radiation exposure data wasn’t available to the public until almost two months after the meltdown occurred. Many residents felt they had been left to guess if dangerous levels of ionising radiation had contaminated their communities or not.

Alarmed by the situation, Dutch electrical engineer and computer scientist Pieter Franken, who was living in Tokyo with his family at the time, felt compelled to act. “After the massive wall of water, we had this invisible wall of radiation that was between myself and my family-in-law in the north of Japan, so that kind of triggered the start of Safecast,” says Pieter.

Pieter Franken, a Dutchman living in Japan, who helped start Safecast
Image credit: Joi Ito – CC BY 2.0

Pieter picked up an idea from Ray Ozzie, the former CTO of Microsoft, who suggested quickly gathering data by attaching Geiger counters – used for measuring radioactivity – to the outside of cars before driving around Fukushima. The only problem was that Geiger counters sold out almost globally in a matter of hours after the tsunami hit, making it even more difficult for Pieter and others on the ground to figure out exactly what was going on. The discussion between Pieter and his friends quickly changed from buying devices to instead building and distributing them to the people of Fukushima.

At Tokyo Hackerspace, Pieter – along with several others, including Joi Ito, the director of the MIT Media Lab, and Sean Bonner, an activist and journalist from Los Angeles – built a series of open-source tools for radiation mapping, to enable anyone to build their own pocket Geiger counter and easily share the data they collect. “Six days after having the idea, we had a working system. The next day we were off to Fukushima,” recalls Sean.

A bGeigie Nano removed from its Pelican hardshell
Safecast CC-BY-NC 4.0

A successful Kickstarter campaign raised $36,900 to provide the funding necessary to distribute hundreds of Geiger counters to the people of Japan, while training volunteers on how to use them. Today, Safecast has collected over 100 million data points and is home to the largest open dataset about environmental radiation in the world. All of the data is collected via the Safecast API and published free of charge in the public domain to an interactive map developed by Safecast and MIT Media Lab.

You can read the rest of this feature in HackSpace magazine issue 14, out today in Tesco, WHSmith, and all good independent UK newsagents.

Or you can buy HackSpace mag directly from us — worldwide delivery is available. And if you’d like to own a handy digital version of the magazine, you can also download a free PDF.

The post From HackSpace mag issue 14: DIY Geiger counters appeared first on Raspberry Pi.

Brand-new books from The MagPi and HackSpace magazine

Post Syndicated from Rob Zwetsloot original https://www.raspberrypi.org/blog/book-of-making-1-magpi-projects-book-4/

Hey folks, Rob from The MagPi here! Halloween is over and November has just begun, which means CHRISTMAS IS ALMOST HERE! It’s never too early to think about Christmas — I start in September, the moment mince pies hit shelves.

Elf GIF

What most people seem to dread about Christmas is finding the right gifts, so I’m here to help you out. We’ve just released two new books: our Official Raspberry Pi Projects Book volume 4, and the brand-new Book of Making volume 1 from the team at HackSpace magazine!

Book of Making volume 1

HackSpace magazine book 1 - Raspberry Pi

Spoiler alert: it’s a book full of making

The Book of Making volume 1 contains 50 of the very best projects from HackSpace magazine, including awesome project showcases and amazing guides for building your own incredible creations. Expect to encounter trebuchets, custom drones, a homemade tandoori oven, and much more! And yes, there are some choice Raspberry Pi projects as well.

The Official Raspberry Pi Projects Book volume 4

The MagPi Raspberry pi Projects book 4

More projects, more guides, and more reviews!

Volume 4 of the Official Raspberry Pi Projects Book is once again jam-packed with Raspberry Pi goodness in its 200 pages, with projects, build guides, reviews, and a little refresher for beginners to the world of Raspberry Pi. Whether you’re new to Pi or have every single model, there’s something in there for you, no matter your skill level.

Free shipping? Worldwide??

You can buy the Book of Making and the Official Raspberry Pi Projects Book volume 4 right now from the Raspberry Pi Press Store, and here’s the best part: they both have free worldwide shipping! They also roll up pretty neatly, in case you want to slot them into someone’s Christmas stocking. And you can also find them at our usual newsagents.

Both books are available as free PDF downloads, so you can try before you buy. When you purchase any of our publications, you contribute toward the hard work of the Raspberry Pi Foundation, so why not double your giving this holiday season by helping us put the power of digital making into the hands of people all over the world?

Anyway, that’s it for now — I’m off for more mince pies!

The post Brand-new books from The MagPi and HackSpace magazine appeared first on Raspberry Pi.

HackSpace magazine 12: build your first rocket!

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-12-build-your-first-rocket/

Move over, Elon Musk — there’s a new rocket maverick in town: YOU!

Rockets!

Step inside the UK rocketry scene, build and launch a rocket, design your own one, and discover the open-source rocket programmes around the world! In issue 12, we go behind the scenes at a top-secret launch site in the English Midlands to have a go at our own rocket launch, find the most welcoming bunch of people we’ve ever met, and learn about centre of gravity, centre of pressure, acceleration, thrust, and a load of other terms that make us feel like NASA scientists.

Meet the Maker: Josef Prusa

In makerception news, we meet the maker who makes makers, Josef Prusa, aka Mr 3D Printing, and we find out what’s next for his open-source hardware empire.

Open Science Hardware

There are more than seven billion people on the planet, and 90-odd percent of them are locked out of the pursuit of science. Fishing, climate change, agriculture: it all needs data, and we’re just not collecting as much as we should. Global Open Science Hardware is working to change that by using open, shared tech — read all about it in issue 12!



And there’s more…

As always, the new issue is packed with projects: make a way-home machine to let your family know exactly when you’ll walk through the front door; build an Alexa-powered wheel of fortune to remove the burden of making your own decisions; and pay homage to Indiana Jones and the chilled monkey brains in Temple of Doom with a capacitive touch haunted monkey skull (no monkeys were harmed in the making of this issue). All that, plus steampunk lighting, LEDs, drills, the world’s biggest selfie machine, and more, just for you. So go forth and make something!

Get your copy of HackSpace magazine

If you like the sound of this month’s content, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK from tomorrow. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine. And if you’d rather try before you buy, you can always download the free PDF now.

Subscribe now

Subscribe now” may not be subtle as a marketing message, but we really think you should. You’ll get the magazine early, plus a lovely physical paper copy, which has a really good battery life.

Oh, and twelve-month print subscribers get an Adafruit Circuit Playground Express loaded with inputs and sensors and ready for your next project. Tempted?

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Electronics 101.1: Electricity basics

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/electronics-101-1-electricity-basics/

In HackSpace issue 9, Dave Astels helps us get familiar with what electricity is, with some key terms and rules, and with a few basic components. Get your copy of HackSpace magazine in stores now, or download it as a free PDF here.

An animated GIF of Pickachu the Pokemon

tl;dr There’s more to electricity than Pikachu.

Electricity basics

Electricity is fascinating. Most of our technology relies on it: computers, lights, appliances, and even cars, as more and more are hybrid or electric. It follows some well-defined rules, which is what makes it so very useful.

According to Wikipedia, electricity is ‘the set of physical phenomena associated with the presence and motion of electric charge’. And what’s electric charge? That’s the shortage or excess of electrons.

Let’s go back (or forward, depending on where you are in life) to high school science and the atom. An atom is, at a very simplified level, a nucleus surrounded by a number of electrons. The nucleus is (again, viewing it simply) made up of neutrons and protons. Neutrons have no charge, but protons have a positive charge. Electrons have a negative charge. The negative charge on a single electron is the exact opposite of the positive charge on a single proton. The simplest atom, hydrogen, is made from a single proton and a single electron. The net charge of the atom is zero: the positive charge of the proton and the negative charge of the electron cancel – or balance – each other. An atom’s electrons aren’t just in an amorphous cloud around the nucleus: you can think of them as being arranged in layers around the nucleus…rather like an onion. Or perhaps an ogre. This is a very simplified visualisation of it, but it suffices for our purposes.

A diagram of a copper atom and the text '29 Electrons'

Figure 1: A very stylised representation of a copper atom with its electron shell

In a more complex atom, say copper, there are more protons, neutrons, and electrons, and the electrons are in more layers. By default, a copper atom has 29 protons and 35 neutrons in its nucleus, which is surrounded by 29 electrons. The way the electrons are distributed in their layers leaves the copper atom with a single electron in the outermost layer. This is represented in Figure 1 (above). Without getting further into subatomic physics, let’s just say that having that single electron in the outermost layer makes it easier to manipulate. When we put a bunch of copper atoms together to make copper metal (e.g. a wire), it’s easy to move those outermost electrons around inside the metal. Those electrons moving around is electricity. The amount of electrons moving over a period of time is called ‘current’.

A multimeter showing the figure 9.99 with a resistor connected via crocodile clips

A single 10 kΩ resistor reads almost 10 000 ohms (no electrical component is perfect).

We started by talking about electrons and charge. Look back at the Wikipedia definition: ‘presence and motion of electric charge’. Charge is measured in coulombs: 1 coulomb is approximately 6.242 × 1018 electrons. That’s 6 242 000 000 000 000 000 electrons. They’re very small. Actually, this would be -1 coulomb. +1 coulomb would be that many protons (or really, the net lack of that many electrons).

That’s charge. Now let’s consider moving charge, which is far more useful in general (unless your goal is to stick balloons to the wall). Consider some amount of charge moving through a wire. The amount of charge that moves past a specific point (and thus through the wire) over a period of time is called ‘current’ (just like the current in a river) and is measured in amperes, generally just called amps. Specifically, 1 amp is equal to 1 coulomb flowing past a point in 1 second.

Another common term is voltage. You can think of voltage like water pressure; it’s the pressure pushing the electrons (i.e. charge) through a material. The higher the voltage (measured in volts), the faster charge is pushed through, i.e. the higher the current.

The final term is resistance, measured in ohms. Resistance is just what it sounds like. It’s a measure of how much a material resists the movement of electrons. We said that copper allows electrons to move freely. That’s what makes it so common for wires, PCB traces, etc. We say that it is a good conductor. Glass, on the other hand, locks its electrons in place, not letting them move. It’s an example of a good insulator. There are materials that are in between: they let electrons move, but not too freely. These are crucial to making electronics work.

There’s an interesting (and useful) relationship between voltage, current, and resistance called Ohm’s Law (Georg Ohm was the fellow who explored and documented this relationship): the current (denoted I, in amps) flowing through a material is equal to the voltage across the material (denoted V, in volts) divided by the material’s resistance (denoted R, in ohms): I = V/R. This equation is foundational and, as such, very handy.

Lighting up

There aren’t many electronic devices that don’t have at least one LED on them somewhere, especially not gadgety ones. If you look at a simple Arduino Uno, it has LEDs for power, Tx, Rx, and pin 13. The first program using electronic components that most people try is one to blink an LED.

A colour spectrum from red to purple

Figure 2: The colour spectrum

LED stands for light-emitting diode. We’ll come back to diodes in a later instalment; all we need to know right now is that a diode has to go the right way around. So that leaves ‘light-emitting’. That simply means that it gives off light: it lights up. Specifically, it lights up when enough current flows through it. Be careful, though. Put too much current through it and it’ll likely crack in two. Seriously, we’ve done it. Best case scenario, you’ll get a bright pulse of light as it burns out. How much current do they like? 20 milliamps (20mA) is typical. Because an LED is a diode, i.e. a semiconductor (we’ll look at these in more detail in a future instalment too), it defies Ohm’s Law. How? It always has the same voltage across it, regardless of the current flowing through it.

An LED will have a specific Vf (f is for forward, as in ‘forward voltage’), which will be defined in its data sheet.

The voltage varies with the colour of light that the LED emits, but usually between 1.8V and 3.3V. Vf for red LEDs will typically be 1.8V, and for blue LEDs 3V–3.3V. As a rule, LEDs with a higher frequency colour will have a larger Vf. Figure 2 (above) shows the colour spectrum. Colours on the right end are lower in frequency and LEDs emitting those colours will have a lower Vf, while those on the left end have a higher frequency and a higher Vf.

A screenshot of resistor-calculator website

Resistor colour bands show the resistance. Online calculators can help you learn the values.

So an LED will have a fixed Vf, and a typical LED that we’ll use likes about 20mA of current. An LED won’t do anything to limit how much current is flowing through it. That’s what we meant when we said it defies Ohm’s Law.

If we take a blue LED and hooked it to a 3.3V power supply, it will shine happily. Do the same thing with a red LED, and it will blink and burn out. So how do we deal with that? How do we use 3.3V or 5V to make an LED light up without burning out? We simply limit the current flowing through it. And for that, we need a resistor and Ohm’s Law.

Getting protection

Figure 3: An LED with a current-limiting resistor

If we want to power a red LED from a 5V source, we know the following information: current has to be 20mA, Vcc will be 5V, and the voltage across the LED will be 1.8V. Consider the circuit in Figure 3. The voltage across the resistor will be Vcc – Vf, i.e. 5 – 1.8 = 3.2V. We said the current through the LED should be 20mA. Since there is only one path through the circuit that goes through the resistor as well as the LED, all current has to flow through both: whatever amount of current flows through the resistor has to flow through the LED, no more, no less. This is the crucial thing to realise. We can calculate the value of the resistance needed using Ohm’s Law: R = V/I = 3.2V/20mA = 3.2V/0.020A = 160 ohms.

The resistor should have a value of 160 ohms to allow 20mA of current to flow through the LED. Knowing that the 20mA and 1.8V values are approximate and that resistors are not exact (+/- 5 or 10 percent are the most common), we chose a slightly higher-value resistor. Considering common resistor values, go with 180 ohm or 220ohm. A higher-value resistor will allow slightly less current through, which might result in a slightly dimmer light. Try it and see. For practical purposes, simply using a 220 ohm resistor usually works fine.

Parallel lines

In the previous section we connected a resistor and an LED end to end. That’s called a series circuit. If we connected them side by side, it would be a parallel circuit. Consider the circuits in Figure 4.

Figure 4: A – series circuit; B – parallel circuit

We’ll use 5V for Vcc. What is the total resistance between Vcc and GND in each circuit? How much current is flowing through each circuit? What is the voltage across each resistor?

When resistors are connected in series, as in circuit A, the resistances are added. So the two 100 ohm resistors in series have a total resistance of 200 ohms.

When resistors are connected in parallel, as in circuit B, it’s more complex. Each resistor provides a path for current to flow through. So we could use an indirect method to calculate the total resistance. Each resistor is 100 ohms, and has one end connected to 5V and the other to 0V (GND), so the voltage across each one is 5V. The current flowing through each one is 5V/100 ohms = 0.05A, or 50mA. That flows through each resistor, so the total current is 100mA, or 0.1A. The total resistance is then R = V/I = 5V/0.1A = 50 ohms. A more direct way is to use the equation 1/Rt = 1/R1 + 1/R2 + … + 1/Rn, where Rt is the total resistance, and R1, R2, etc. are the values of the individual resistors that are in parallel. Using this, 1/Rt = 1/100 + 1/100 = 2/100 = 1/50. So Rt = 50. This is a quicker way to do it, and only involves the resistor values.

An image of a multimeter

A multimeter can read voltage, ampage, and resistance

Now for current. We know that the series circuit has a total resistance of 200 ohms, so the current will be I = V/R = 5V/200 ohm = 0.025A = 25mA. For one 100 ohm resistor the current is 5V/100 ohm = 0.05A = 50mA. This is expected: if the resistance is lower, there is less ‘resistance’ to current flowing, so with the same voltage, more current will flow. We already computed the current for the parallel circuit: 100mA. This is higher because we know that each resistor has 50mA flowing through it. In a parallel circuit, the currents are added.

A multimeter showing the figure 19.88 with a resistor connected via crocodile clips

Two 10kΩ (kiloohm) resistors in series read (almost) 20kΩ

The final question is what voltage is across each resistor. Let’s look at the parallel circuit first. One end of each resistor is connected to 5V, and the other end of each is connected to 0V (GND). So clearly, the voltage across each one is 5V. In a series circuit it’s different. We can use Ohm’s Law because we’ve calculated the current flowing through each one (0.025A), and that current flows through both resistors. Each resistor is 100 ohm, so the voltage across each one will be V = I×R = 0.025A × 100 ohm = 2.5 V. This makes sense intuitively, since the resistors have the same value and the same current is flowing through both. It makes sense that the voltage across each would be equal, and half of the total. Remember that it’s unlikely to be exactly half, due to the slop in the resistor values.

Let’s do this one more time with unequal resistors. See Figure 5.

Figure 5: A – series circuit; B – parallel circuit

For the series circuit, we simply add the resistances: 100ohm + 82ohm = 182ohm. The current is 5V / 182ohm = 0.0274725A = 27.4725 mA. Because resistors are inexact, it’s safe to call this 27.5mA. The voltages are 100ohm × 0.0275A = 2.75V across the 100 ohm resistor, and 82ohm × 0.275 = 2.25V across the 82 ohm one. The voltages always have to add up, accepting rounding errors. Relative to ground, the voltage at the point between the resistors is 2.75V. What will happen if we make the top resistor smaller (i.e. have a lower resistance)? The total resistance goes down, the current goes up, so the voltage across the 100ohm resistor goes up. This is what’s generally called a voltage divider.

For the parallel circuit we can use 1/Rt = 1/100 + 1/82 = 82/8200 + 100/8200 = 182/8200 = 1/45, so Rt = 45ohm. The total current is 5V / 45ohm = 0.111A = 111mA. For the individual resistors, the currents are 5V / 100ohm = 50mA and 5V / 82ohm = 61mA. Add these up and we have the total current of 111mA. Parallel resistors act as a current divider.

A multimeter showing the figure 4.96 with a resistor connected via crocodile clips

Two 10kΩ resistors in parallel read (almost) 5kΩ.

I encourage you to create these little circuits on a breadboard and measure the resistances, voltages, and currents for yourself.

Resistors in series for a voltage divider, resisters in parallel for a current divider

Consider what happens if we replace the resistor connected to Vcc in a series circuit with a variable resistor. The voltage between the resistors will vary as the value of the resistor does. As the resistance goes down, the voltage goes up. The reverse is true as well: as the resistance goes up, the voltage goes down. One use of this is to replace the variable resistor with a photoresistor. A photoresistor’s value depends on how much light is shining on it (i.e. how many photons are hitting it, to be precise). More light = lower resistance. Now the voltage divider can be used to measure the strength of light. All you need to do is connect the point between the resistors to an analogue input and read it.

Figure 6 Combined parallel and series circuits

We’ve had a brief look at the basic concepts of electricity: charge, current, voltage, and resistance. We’ve also had a closer look at resistors and ways of combining them. We finished with a practical example of a series resistor circuit being used to measure light.

The post Electronics 101.1: Electricity basics appeared first on Raspberry Pi.

HackSpace magazine issue 11: best maker hardware

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-11-best-maker-hardware/

Today is that glorious day of the month when a new issue of HackSpace magazine comes out!

HackSpace magazine #11: All you can hardware

The cream of this year’s hardware crop

You’re on safe and solid ground with an Arduino, or one of Adafruit’s boards — so much so that many makers get comfortable and never again look at the other options that are out there. With the help of Hackster’s chief hardware nerd Alex Glow, we’re here to open your eyes to the new devices and boards that could really kick your making into gear. We know it’s easy to stick with what you know, but trust us — hacker tech is getting better all the time. So try something new!

Hackspace magazine hardware feature spread

One man and his shed shack

If you want to learn stuff like how to build a workbench that includes a voice-activated beer dispenser, then check out Al’s Hack Shack on Youtube.

Al's Hack Shack

We went to see the man inside the shack to learn about the maker community’s love of sharing, why being grown-up means you get more time to play, and why making is good for your mental health.

Hacky Racers

Maker culture shows itself in all sorts of quirky forms. The one we’re portraying in issue 11 is the Hacky Racers: motorsport meets Robot Wars meets mud. Lots of mud. If you feel the need, the need for speed (or mud), then get involved!

Hacky Racers

Laser harp

Yes, you read that right! At HackSpace magazine, we get a lot of gear coming in for us to test, but few items have given us more joy than this laser harp.

It’s easy to build, it’s affordable, and it poses only a very small risk of burning out your retinas. It’s the most fun you can have for £8.59 including postage. Promise. Read our full review in this month’s issue!

And there’s more!

We demystify PAT testing, help you make sense of circuit design with a beginners’ guide to Tinkercad, tell you why you need an angle grinder, and show you the easiest way we’ve ever seen of keeping knives sharp. All this and more, in your latest issue of HackSpace magazine!

Get your copy of HackSpace magazine

If you like the sound of this month’s content, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine. And if you’d rather try before you buy, you can always download the free PDF.

Subscribe now

Subscribe now” may not be subtle as a marketing message, but we really think you should. You’ll get the magazine early, plus a lovely physical paper copy, which has really good battery life.

Oh, and twelve-month print subscribers get an Adafruit Circuit Playground Express loaded with inputs and sensors and ready for your next project. Tempted?

The post HackSpace magazine issue 11: best maker hardware appeared first on Raspberry Pi.

HackSpace magazine 10: build a drone

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-10-build-a-drone/

If you’re a subscriber to HackSpace magazine you’ll already know all about issue 10. For the rest of you who’ve yet to subscribe, issue 10 is out today!

HackSpace magazine 10 Raspberry Pi Press

Build a drone

Ever since Icarus flew too close to the sun, man has dreamed of flight. Thanks to brushless motors, cheaper batteries than ever before, and smaller, more powerful microcontrollers, pretty much anyone with the right know-how can build their own drone. Discover the crucial steps you need to get right; find the right motors, propellers, and chassis; then get out there while the weather is still good and soar like a PCB eagle.

HackSpace magazine 10 Raspberry Pi Press

Rocket-launching robot

If you prefer to keep your remote-controlled vehicles on the ground, we have an inspiring tale of how one maker combined a miniature strandbeest with our other great obsession (fire, obviously) to create a unique firework launcher. Guy Fawkes would surely be pleased.

HackSpace magazine 10 Raspberry Pi Press

Hardware hacking for the environment

In less frivolous project news, we’re reporting from the Okavango Delta in Botswana, where open hardware, open data, and the hard work of volunteers are giving ecologists more information about this essential wetland region. Makers are bringing science out of labs and classrooms, and putting it into the hands of citizen scientists who want to understand and protect their local environment – that’s something we should be proud of.

HackSpace magazine 10 Raspberry Pi Press

PCBs win prizes

The Hackaday Prize: the Academy Awards of open hardware. Enter your project today and you stand a chance of winning $50,000. The competition is fierce, so before you do, read our interview with Stephen Tranovich. Stephen is the Technical Community Lead at the Hackaday Prize and decides who gets the chance to win the glittering prizes. Learn from their words!

HackSpace magazine 10 Raspberry Pi Press

Food

Our editor Ben loves to eat, so this month he’s been eating lamb kebabs cooked in his home-made tandoor. This ancient cooking method is used all over the Indian subcontinent, and imparts a unique flavour with its combination of heat and steam. Best of all, you can make your own tandoor oven with a Dremel and a few plant pots.

HackSpace magazine 10 Raspberry Pi Press

Tutorials



Add push notifications to your letterbox (so your dog doesn’t eat your new passport), write a game for an Arduino, add a recharging pocket to a bag so you can Instagram on the go, and learn everything there is to know about capacitors. All this and more, in HackSpace magazine issue 10!

Get your copy of HackSpace magazine

If you like the sound of this month’s content, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine. And if you’d rather try before you buy, you can always download the free PDF.

Subscribe now

Subscribe now” may not be subtle as a marketing message, but we really think you should. You’ll get the magazine early, plus a lovely physical paper copy, which has really good battery life.

HackSpace magazine 10 Raspberry Pi Press

Oh, and twelve-month print subscribers get an Adafruit Circuit Playground Express loaded with inputs and sensors and ready for your next project. Tempted?

The post HackSpace magazine 10: build a drone appeared first on Raspberry Pi.

Build a social media follower counter

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/build-social-media-follower-counter/

In this tutorial from HackSpace magazine issue 9, Paul Freeman-Powell shows you how to keep track of your social media followers, and encourage subscribers, by building a live follower counter. Get your copy of HackSpace magazine in stores now, or download it as a free PDF here.

Issues 10 of HackSpace magazine is available online and in stores from tomorrow!

The finished build with all components connected, working, and installed in the frame ready for hanging on the wall

If you run a local business like an electronics shop or a café, or if you just want to grow your online following and influence, this project is a fun way to help you keep track of your progress. A counter could also help contribute to growing your following if you hang it on the wall and actively ask your customers to like/follow you to see the numbers go up!

You’ve probably seen those social media follower counters that feature mechanical splitflap displays. In this project we’ll build a counter powered by RGB LEDs that scrolls through four social profiles, using APIs to pull the number of followers for each account. I’m using YouTube, Twitter, Facebook, and Instagram; you can, of course, tailor the project to your needs.

This project involves a bit of electronics, a bit of software coding, and a bit of woodwork, as well as some fairly advanced display work as we transfer a small portion of the Raspberry Pi’s HDMI output onto the LED matrices.

Let’s get social

First, you need to get your Raspberry Pi all set up and talking to the social networks that you’re going to display. Usually, it’s advisable to install Raspbian without any graphical user interface (GUI) for most electronics projects, but in this case you’ll be actively using that GUI, so make sure you start with a fresh and up-to-date installation of full-fat Raspbian.

phpMyAdmin gives you an easy web interface to allow you to access and edit the device’s settings – for example, speed and direction of scrolling, API credentials, and the social network accounts to monitor

You start by turning your humble little Raspberry Pi into your very own mini web server, which will gather your credentials, talk to the social networks, and display the follower counts. To do this, you need to install a LAMP (Linux, Apache, MySQL, PHP) stack. Start by installing the Apache web server by opening a Terminal and typing:

sudo apt-get install apache2 -y

Then, open the web browser on your Pi and type http://localhost — you will see a default page telling you that Apache is working. The page on our little ‘website’ will use code written in the PHP language, so install that by returning to your Terminal and typing:

sudo apt-get install php -y

Once that’s complete, restart Apache:

sudo service apache2 restart

Next, you’ll install the database to store your credentials, settings, and the handles of the social accounts to track. This is done with the following command in your Terminal:

sudo apt-get install mysql-server php-mysql -y

To set a root password for your database, type the following command and follow the on-screen instructions:

sudo mysql_secure_installation

Restart Apache again. Then, for easier management of the database, I recommend installing phpMyAdmin:

sudo apt-get install phpMyAdmin -y

At this point, it’s a good idea to connect your Pi to a WiFi network, unless you’re going to be running a network cable to it. Either way, it’s useful to have SSH enabled and to know its IP address so we can access it remotely. Type the following to access Pi settings and enable SSH:

sudo raspi-config

To determine your Pi’s IP address (which will likely be something like 192.168.0.xxx), type either of the following two commands:

ifconfig # this gives you lots of extra info
hostname -I # this gives you less info, but all we need in this case

Now that SSH is enabled and you know the LAN IP address of the Pi, you can use PuTTY to connect to it from another computer for the rest of your work. The keyboard, mouse, and monitor can now be unplugged from the Raspberry Pi.

Social media monitor

To set up the database, type http://XXX/ phpmyadmin (where XXX is your Pi’s IP address) and log in as root with the password you set previously. Head to the User Accounts section and create a new user called socialCounter.

You can now download the first bit of code for this project by running this in your Terminal window:

cd /var/www/html

sudo apt-get update

sudo apt-get install git -y

sudo git clone https://github.com/paulfp/social- media-counter.git

Next, open up the db.php script and edit it to include the password you set when creating the socialCounter user:

cd ./social-media-counter

sudo nano db.php

The database, including tables and settings, is contained in the socialCounter.sql file; this can be imported either via the Terminal or via phpMyAdmin, then open up the credentials table. To retrieve the subscriber count, YouTube requires a Google API key, so go to console.cloud.google.com and create a new Project (call it anything you like). From the left-hand menu, select ‘APIs & Services’, followed by ‘Library’ and search for the YouTube Data API and enable it. Then go to the ‘Credentials’ tab and create an API key that you can then paste into the ‘googleApiKey’ database field.

Facebook requires you to create an app at developers.facebook.com, after which you can paste the details into the facebookAppId and facebookSecret fields. Unfortunately, due to recent scandals surrounding clandestine misuse of personal data on Facebook, you’ll need to submit your app for review and approval before it will work.

The ‘social_accounts’ table is where you enter the user names for the social networks you want to monitor, so replace those with your own and then open a new tab and navigate to http://XXX/socialmedia-counter. You should now see a black page with a tiny carousel showing the social media icons plus follower counts next to each one. The reason it’s so small is because it’s a 64×16 pixel portion of the screen that we’ll be displaying on our 64×16 LED boards.

GPIO pins to LED display

Now that you have your social network follower counts being grabbed and displayed, it’s time to get that to display on our screens. The first step is to wire them up with the DuPont jumper cables from the Raspberry Pi’s GPIO pins to the connection on the first board. This is quite fiddly, but there’s an excellent guide and diagram on GitHub within Henner Zeller’s library that we’ll be using later, so head to hsmag.cc/PLyRcK and refer to wiring.md.

The Raspberry Pi connects to the RGB LED screens with 14 jumper cables, and the screens are daisy-chained together with a ribbon cable

The second screen is daisy-chained to the first one with the ribbon cable, and the power connector that comes with the screens will plug into both panels. Once you’re done, your setup should look just like the picture on this page.

To display the Pi’s HDMI output on the LED screens, install Adafruit’s rpi-fb-matrix library (which in turn uses Henner Zeller’s library to address the panels) by typing the following commands:

sudo apt-get install -y build-essential libconfig++-dev

cd ~

git clone --recursive https://github.com/ adafruit/rpi-fb-matrix.git

cd rpi-fb-matrix

Next, you must define your wiring as regular. Type the following to edit the Makefile:

nano Makefile

Look for the HARDWARE_DESC= property and ensure the line looks like this: export HARDWARE_DESC=regular before saving and exiting nano. You’re now ready to compile the code, so type this and then sit back and watch the output:

make clean all

Once that’s done, there are a few more settings to change in the matrix configuration file, so open that up:

nano matrix.cfg

You need to make several changes in here, depending on your setup:

  • Change display_width to 64 and display_height to 16
  • Set panel_width to 32 and panel_height to 16
  • Set chain_length to 2
  • Set parallel_count to 1

The panel array should look like this:

panels = ( 
  ( { order = 1; rotate = 0; }, { order = 0; rotate = 0; } )
)

Uncomment the crop_origin = (0, 0) line to tell the tool that we don’t want to squish the entire display onto our screens, just an equivalent portion starting right in the top left of the display. Press CTRL+X, then Y, then ENTER to save and exit.

It ain’t pretty…but it’s out of sight. The Raspberry Pi plus the power supply for the screens fit nice and neatly behind the screens. I left each end open to allow airflow

Finally, before you can test the output, there are some other important settings you need to change first, so open up the Raspberry Pi’s boot configuration as follows:

sudo nano /boot/config.txt

First, disable the on-board sound (as it uses hardware that the screens rely on) by looking for the line that says dtparam=audio=on and changing it to off. Also, uncomment the line that says hdmi_force_hotplug=1, to ensure that an HDMI signal is still generated even with no HDMI monitor plugged in. Save and then reboot your Raspberry Pi.

Now run the program using the config you just set:

cd ~/rpi-fb-matrix

sudo ./rpi-fb-matrix matrix.cfg

You should now see the top 64×16 pixels of your Pi’s display represented on your RGB LED panels! This probably consists of the Raspberry Pi icon and the rest of the top portion of the display bar.

No screensaver!

At this point it’s important to ensure that there’s no screensaver or screen blanking enabled on the Pi, as you want this to display all the time. To disable screen blanking, first install the xscreensaver tool:

sudo apt-get install xscreensaver

That will add a screensaver option to the Pi’s GUI menus, allowing you to disable it completely. Finally, you need to tell the Raspberry Pi to do two things each time it loads:

  • Run the rpi-fb-matrix program (like we did manually just now)
  • Open the web browser in fullscreen (‘kiosk’ mode), pointed to the Social Counter web page

To do so, edit the Pi’s autostart configuration file:

sudo nano ~/.config/lxsession/LXDE-pi/autostart

Insert the following two lines at the end:

@sudo /home/pi/rpi-fb-matrix/rpi-fb-matrix /home/ pi/rpi-fb-matrix/matrix.cfg\

@chromium-browser --kiosk http://localhost/ social-media-counter

Et voilà!

Disconnect any keyboard, monitor, or mouse from the Pi and reboot it one more time. Once it’s started up again, you should have a fully working display cycling through each enabled social network, showing up-to-date follower counts for each.

It’s now time to make a surround to hold all the components together and allow you to wall-mount your display. The styling you go for is up to you — you could even go all out and design and 3D print a custom package.

The finished product, in pride of place on the wall of our office. Now I just need some more subscribers…!

For my surround, I went for the more rustic and homemade look, and used some spare bits of wood from an internal door frame lining. This worked really well due to the pre-cut recess. With a plywood back, you can screw everything together so that the wood holds the screens tightly enough to not require any extra fitting or gluing, making for easier future maintenance. To improve the look and readability of the display (as well as soften the light and reduce the brightness), you can use a reflective diffuser from an old broken LED TV if you can lay your hands on one from eBay or a TV repair shop, or just any other bit of translucent material. I found that two layers stapled on worked and looked great. Add some hooks to the back and — Bob’s your uncle — a finished, wall-mounted display!

Phew — that was quite an advanced build, but you now have a sophisticated display that can be used for any number of things and should delight your customers whilst helping to build your social following as well. Don’t forget to tweet us a picture of yours!

The post Build a social media follower counter appeared first on Raspberry Pi.

Hackspace magazine 9: tools, tools, tools

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-9/

Rejoice! It’s time for a new issue of Hackspace magazine, packed with things for you to make, build, hack, and create!

raspberry pi press hackspace magazine

 

HackSpace magazine issue 9

Tools: they’re what separates humans from the apes! Whereas apes use whatever they find around them to get honey, pick pawpaws, and avoid prickly pears, we humans take the step of making things with which to make other things. That’s why in this issue of HackSpace magazine, we look at 50 essential tools to make you better at making (and by extension better at being a human). Take a look, decide which ones you need, and imagine the projects that will be possible with your shiny new stuff.

Konichiwakitty

In issue 9, we feature Konichiwakitty, known as Rachel Wong to her friends, who is taking the maker world by storm with her range of electronic wearables.



Alongside making wearables and researching stem cells, she also advocates for getting young people into crafting, including making their own wearables!

Helping

Remap is a fantastic organisation. It’s comprised of volunteer makers and builders who use their skills to adapt the world and build tech to help people with disabilities. Everyone in the maker community can do amazing stuff, and it’s wonderful that so many of you offer your time and skills for free to benefit people in need.

Music

The band Echo and the Bunnymen famously credited a drum machine as a band member, and with our tutorial, you too can build your own rhythm section using a Teensy microcontroller, a breadboard, and a few buttons.



And if that’s not enough electro beats for you, we’ve also got a guide to generating MIDI inputs with a joystick — because keyboards and frets are so passé.

Pi Wars

Having shiny new stuff on its own isn’t enough to spur most people to action. No, they need a reason to make, for example total mechanical dominance over their competitors. Offering an arena for such contests is the continuing mission of Tim Richardson, who along with Mike Horne created Pi Wars.



In its five-ish years, Pi Wars has become one of the biggest events on the UK maker calendar, with an inspired mix of robots, making, programming, and healthy competition. We caught up with Tim to find out how to make a maker event, what’s next for Pi Wars, and how to build a robot to beat the best.

Fame

Do you ever lie awake at night wondering how many strangers on the internet like you? If so (or if you have a business with a social media presence, which seems more likely), you might be interested in our tutorial for a social media follower counter.

raspberry pi press hackspace magazine

This build takes raw numbers from the internet’s shouting forums and turns them into physical validation, so you can watch your follower count increase in real time as you shout into the void about whether Football’s Coming Home. 

And there’s more…

In this issue, you can also:

  • See how to use the Google AIY Projects Vision kit to turn a humble water pistol into a single-minded dousing machine that doesn’t feel pity, fear, or remorse
  • Find out how to make chocolate in whatever shape you want
  • Learn from a maker who put 20 hours work into a project only to melt her PCBs and have to start all over again (spoiler alert: it all worked out in the end)

All this, plus a bunch of reviews and many, many more projects to dig into, in Hackspace magazine issue 9.

Get your copy of HackSpace magazine

If you like the sound of this month’s content, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine. And if you’d rather try before you buy, you can always download the free PDF.

Subscribe now

Subscribe now” may not be subtle as a marketing message, but we really think you should. You’ll get the magazine early, plus a lovely physical paper copy, which has really good battery life.

raspberry pi press hackspace magazine

Oh, and 12-month print subscribers get an Adafruit Circuit Playground Express loaded with inputs and sensors and ready for your next project.

The post Hackspace magazine 9: tools, tools, tools appeared first on Raspberry Pi.

HackSpace magazine 8: Raspberry Pi <3 Arduino

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-8/

Arduino is officially brilliant. It’s the perfect companion for your Raspberry Pi, opening up new possibilities for robotics, drones and all sorts of physical computing projects. In HackSpace magazine issue 8  we’re taking a look at what’s going on on planet Arduino, and how it can make our world better.

HackSpace magazine

This little board and its ecosystem are hugely important to the world of digital making. It’s affordable, it’s powerful, and it’s open hardware so you know that if you embed one of these in a project and the company goes bust tomorrow, the hardware will always be viable.

Arduino has helped power a new generation of digital makers, and now with a new team in charge, new boards and new software, it’s ready for the next generation.

Noisy toys

We get to speak to loads of fascinating people, but this month marks the first time we’ve ever met a science busker. Meet Stephen Summers, a former teacher who makes a mess with cornflour, water, and sound waves, all in the name of sharing the joy of physics.

HackSpace magazine

Glass-blowing

While we love messing about with digital technologies, we’re also a big fan of good old-fashioned craft skills. And you can’t get much more old-fashioned than traditional glass-blowing. Join us as we attempt to turn red hot molten glass into a multicoloured object without burning ourselves or setting anything on fire.

Guitar synth

People are endlessly clever, inventive, and all-round brilliant. A fantastic example is Björk, the Icelandic musician whose work defies categorisation. Another is Matt Bradshaw, who has made a synthesiser that you play by strumming six metal strings with a plectrum to complete a circuit. Oh, and named it after Björk. Read all about it and get inspired to do something equally bonkers.

HackSpace magazine

Machine learning

Do you have children? Do they leave the lights on all the time, causing you to shout, “THIS ISN’T BLACKPOOL FLAMING ILLUMINATIONS, YOU KNOW!” Well, now you can replace those children with an Arduino. With a bit of machine learning, the Arduino can train itself to turn the lights on and off at the right time, all the time. Plus they don’t cost as much as human children, so it’s a double win!

Dry ice cream

When the sun comes out in Blighty, it doesn’t hang around for long. So why wait for your domestic fridge to freeze your tasty dairy-based desserts, when you can add some solid carbon dioxide and freeze it in a flash? Follow our tutorial and you too can have tasty treats with the ironically warm glow that comes from using chemicals at -78°C.

HackSpace magazine

And there’s more

We’ve filled the rest of the magazine with a robot orchestra, watch restoration, audio boards for Raspberry Pi, magical colour-changing wearables, and more. Get stuck in!



Get your copy of HackSpace magazine

If you like the sound of this month’s content, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine.

And if you can’t get to the shops, fear not: you can subscribe from £4 an issue from our online shop. And if you’d rather try before you buy, you can always download the free PDF. Happy reading, and happy making!

The post HackSpace magazine 8: Raspberry Pi <3 Arduino appeared first on Raspberry Pi.

HackSpace magazine 7: Internet of Everything

Post Syndicated from Andrew Gregory original https://www.raspberrypi.org/blog/hackspace-magazine-7-internet-of-everything/

We’re usually averse to buzzwords at HackSpace magazine, but not this month: in issue 7, we’re taking a deep dive into the Internet of Things.HackSpace magazine issue 7 cover

Internet of Things (IoT)

To many people, IoT is a shady term used by companies to sell you something you already own, but this time with WiFi; to us, it’s a way to make our builds smarter, more useful, and more connected. In HackSpace magazine #7, you can join us on a tour of the boards that power IoT projects, marvel at the ways in which other makers are using IoT, and get started with your first IoT project!

Awesome projects

DIY retro computing: this issue, we’re taking our collective hat off to Spencer Owen. He stuck his home-brew computer on Tindie thinking he might make a bit of beer money — now he’s paying the mortgage with his making skills and inviting others to build modules for his machine. And if that tickles your fancy, why not take a crack at our Z80 tutorial? Get out your breadboard, assemble your jumper wires, and prepare to build a real-life computer!

Inside HackSpace magazine issue 7

Shameless patriotism: combine Lego, Arduino, and the car of choice for 1960 gold bullion thieves, and you’ve got yourself a groovy weekend project. We proudly present to you one man’s epic quest to add LED lights (controllable via a smartphone!) to his daughter’s LEGO Mini Cooper.

Makerspaces

Patriotism intensifies: for the last 200-odd years, the Black Country has been a hotbed of making. Urban Hax, based in Walsall, is the latest makerspace to show off its riches in the coveted Space of the Month pages. Every space has its own way of doing things, but not every space has a portrait of Rob Halford on the wall. All hail!

Inside HackSpace magazine issue 7

Diversity: advice on diversity often boils down to ‘Be nice to people’, which might feel more vague than actionable. This is where we come in to help: it is truly worth making the effort to give people of all backgrounds access to your makerspace, so we take a look at why it’s nice to be nice, and at the ways in which one makerspace has put niceness into practice — with great results.

And there’s more!

We also show you how to easily calculate the size and radius of laser-cut gears, use a bank of LEDs to etch PCBs in your own mini factory, and use chemistry to mess with your lunch menu.

Inside HackSpace magazine issue 7
Helen Steer inside HackSpace magazine issue 7
Inside HackSpace magazine issue 7

All this plus much, much more waits for you in HackSpace magazine issue 7!

Get your copy of HackSpace magazine

If you like the sound of that, you can find HackSpace magazine in WHSmith, Tesco, Sainsbury’s, and independent newsagents in the UK. If you live in the US, check out your local Barnes & Noble, Fry’s, or Micro Center next week. We’re also shipping to stores in Australia, Hong Kong, Canada, Singapore, Belgium, and Brazil, so be sure to ask your local newsagent whether they’ll be getting HackSpace magazine.

And if you can’t get to the shops, fear not: you can subscribe from £4 an issue from our online shop. And if you’d rather try before you buy, you can always download the free PDF. Happy reading, and happy making!

The post HackSpace magazine 7: Internet of Everything appeared first on Raspberry Pi.