Tag Archives: MIDI

Playing The Doors with a door (and a Raspberry Pi)

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/playing-the-doors-with-a-door-and-a-raspberry-pi/

Floyd Steinberg is back with more synthy Raspberry Pi musical magic, this time turning a door into a MIDI controller.

I played The Doors on a door – using a Raspberry PI DIY midi controller and a Yamaha EX5

You see that door? You secretly want that to be a MIDI controller? Here’s how to do it, and how to play a cover version of “Break On Through” by The Doors on a door 😉 Link to source code and the DIY kit below.

If you don’t live in a home with squeaky doors — living room door, I’m looking at you — you probably never think about the musical potential of mundane household objects.

Unless you’re these two, I guess:

When Mama Isn’t Home / When Mom Isn’t Home ORIGINAL (the Oven Kid) Timmy Trumpet – Freaks

We thought this was hilarious. Hope you enjoy! This video has over 60 million views worldwide! Social Media: @jessconte To use this video in a commercial player, advertising or in broadcasts, please email [email protected]

If the sound of a slammed oven door isn’t involved in your ditty of choice, you may instead want to add some electronics to that sweet, sweet harmony maker, just like Floyd.

Trusting in the melodic possibilities of incorporating a Raspberry Pi 3B+ and various sensory components into a humble door, Floyd created The Doors Door, a musical door that plays… well, I’m sure you can guess.

If you want to build your own, you can practice some sophisticated ‘copy and paste’ programming after downloading the code. And for links to all the kit you need, check out the description of the video over on YouTube. While you’re there, be sure to give the video a like, and subscribe to Floyd’s channel.

And now, to get you pumped for the weekend, here’s Jim:

The Doors – Break On Through HQ (1967)

recorded fall 1966 – lyrics: You know the day destroys the night Night divides the day Tried to run Tried to hide Break on through to the other side Break on through to the other side Break on through to the other side, yeah We chased our pleasures here Dug our treasures there But can you still recall The time we cried Break on through to the other side Break on through to the other side Yeah!

The post Playing The Doors with a door (and a Raspberry Pi) appeared first on Raspberry Pi.

Bind MIDI inputs to LED lights using a Raspberry Pi

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/midi-controlled-led-lights-raspberry-pi/

Blinky lights and music created using a Raspberry Pi? Count us in! When Aaron Chambers shared his latest project, Py-Lights, on Reddit, we were quick to ask for more information. And here it is:

Controlling lights with MIDI commands

Tentatively titled Py-Lights, Aaron’s project allows users to assign light patterns to MIDI actions, creating a rather lovely blinky light display.

For his example, Aaron connected a MIDI keyboard to a strip of RGB LEDs via a Raspberry Pi that ran his custom Python code.

Aaron explains on Reddit:

The program I made lets me bind “actions” (strobe white, flash blue, disable all colors, etc.) to any input and any input type (hold, knob, trigger, etc.). And each action type has a set of parameters that I bind to the input. For example, I have a knob that changes a strobe’s intensity, and another knob that changes its speed.

The program updates each action, pulls its resulting color, and adds them together, then sends that to the LEDs. I’m using rtmidi for reading the midi device and pigpio for handling the LED output.

Aaron has updated the Py-Lights GitHub repo for the project to include a handy readme file and a more stable build.

The post Bind MIDI inputs to LED lights using a Raspberry Pi appeared first on Raspberry Pi.

Security updates for Wednesday

Post Syndicated from ris original https://lwn.net/Articles/748276/rss

Security updates have been issued by Arch Linux (mbedtls), CentOS (gcab and java-1.7.0-openjdk), Debian (drupal7, lucene-solr, wavpack, and xmltooling), Fedora (dnsmasq, gcab, gimp, golang, knot-resolver, ldns, libsamplerate, mingw-OpenEXR, mingw-poppler, python-crypto, qt5-qtwebengine, sblim-sfcb, systemd, unbound, and wavpack), Mageia (ioquake3, TiMidity++, tomcat, tomcat-native, and wireshark), openSUSE (systemd and zziplib), Red Hat (erlang and openstack-nova and python-novaclient), and SUSE (kernel).

Security updates for Monday

Post Syndicated from ris original https://lwn.net/Articles/748073/rss

Security updates have been issued by Arch Linux (lib32-wavpack, phpmyadmin, unixodbc, and wavpack), Debian (drupal7, golang, imagemagick, libdatetime-timezone-perl, libvpx, and tzdata), Fedora (exim, irssi, kernel, milkytracker, qt5-qtwebengine, seamonkey, and suricata), Mageia (advancecomp, apache-commons-email, freetype2, ghostscript, glpi, jackson-databind, kernel, mariadb, and postgresql), openSUSE (dhcp, GraphicsMagick, lame, php5, phpMyAdmin, timidity, and wireshark), and Oracle (kernel).

The Fisher Piano: make music in the air

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/air-piano/

Piano keys are so limiting! Why not swap them out for LEDs and the wealth of instruments in Pygame to build air keys, as demonstrated by Instructables maker 2fishy?

Raspberry Pi LED Light Schroeder Piano – Twinkle Little Star

Raspberry Pi LED Light Schroeder Piano – Twinkle Little Star

Keys? Where we’re going you don’t need keys!

This project, created by either Yolanda or Ken Fisher (or both!), uses an array of LEDs and photoresistors to form a MIDI sequencer. Twelve LEDs replace piano keys, and another three change octaves and access the menu.

Each LED is paired with a photoresistor, which detects the emitted light to form a closed circuit. Interrupting the light beam — in this case with a finger — breaks the circuit, telling the Python program to perform an action.

2fishy LED light piano raspberry pi

We’re all hoping this is just the scaled-down prototype of a full-sized LED grand piano

Using Pygame, the 2fishy team can access 75 different instruments and 128 notes per instrument, making their wooden piano more than just a one-hit wonder.

Piano building

The duo made the piano’s body out of plywood, hardboard, and dowels, and equipped it with a Raspberry Pi 2, a speaker, and the aforementioned LEDs and photoresistors.

2fishy LED light piano raspberry pi

A Raspberry Pi 2 and speaker sit within the wooden body, with LEDs and photoresistors in place of the keys.

A complete how-to for the build, including some rather fancy and informative schematics, is available at Instructables, where 2fishy received a bronze medal for their project. Congratulations!

Learn more

If you’d like to learn more about using Pygame, check out The MagPi’s Make Games with Python Essentials Guide, available both in print and as a free PDF download.

And for more music-based projects using a variety of tech, be sure to browse our free resources.

Lastly, if you’d like to see more piano-themed Raspberry Pi projects, take a look at our Big Minecraft Piano, these brilliant piano stairs, this laser-guided piano teacher, and our video below about the splendid Street Fighter duelling pianos we witnessed at Maker Faire.

Pianette: Piano Street Fighter at Maker Faire NYC 2016

Two pianos wired up as Playstation 2 controllers allow users to battle…musically! We caught up with makers Eric Redon and Cyril Chapellier of foobarflies a…

The post The Fisher Piano: make music in the air appeared first on Raspberry Pi.

Astro Pi celebrates anniversary of ISS Columbus module

Post Syndicated from David Honess original https://www.raspberrypi.org/blog/astro-pi-celebrates-anniversary/

Right now, 400km above the Earth aboard the International Space Station, are two very special Raspberry Pi computers. They were launched into space on 6 December 2015 and are, most assuredly, the farthest-travelled Raspberry Pi computers in existence. Each year they run experiments that school students create in the European Astro Pi Challenge.

Raspberry Astro Pi units on the International Space Station

Left: Astro Pi Vis (Ed); right: Astro Pi IR (Izzy). Image credit: ESA.

The European Columbus module

Today marks the tenth anniversary of the launch of the European Columbus module. The Columbus module is the European Space Agency’s largest single contribution to the ISS, and it supports research in many scientific disciplines, from astrobiology and solar science to metallurgy and psychology. More than 225 experiments have been carried out inside it during the past decade. It’s also home to our Astro Pi computers.

Here’s a video from 7 February 2008, when Space Shuttle Atlantis went skywards carrying the Columbus module in its cargo bay.

STS-122 Launch NASA TV Coverage

From February 7th, 2008 NASA-TV Coverage of The 121st Space Shuttle Launch Launched At:2:45:30 P.M E.T – Coverage begins exactly one hour till launch STS-122 Crew:

Today, coincidentally, is also the deadline for the European Astro Pi Challenge: Mission Space Lab. Participating teams have until midnight tonight to submit their experiments.

Anniversary celebrations

At 16:30 GMT today there will be a live event on NASA TV for the Columbus module anniversary with NASA flight engineers Joe Acaba and Mark Vande Hei.

Our Astro Pi computers will be joining in the celebrations by displaying a digital birthday candle that the crew can blow out. It works by detecting an increase in humidity when someone blows on it. The video below demonstrates the concept.

AstroPi candle

Uploaded by Effi Edmonton on 2018-01-17.

Do try this at home

The exact Astro Pi code that will run on the ISS today is available for you to download and run on your own Raspberry Pi and Sense HAT. You’ll notice that the program includes code to make it stop automatically when the date changes to 8 February. This is just to save time for the ground control team.

If you have a Raspberry Pi and a Sense HAT, you can use the terminal commands below to download and run the code yourself:

wget http://rpf.io/colbday -O birthday.py
chmod +x birthday.py

When you see a blank blue screen with the brightness increasing, the Sense HAT is measuring the baseline humidity. It does this every 15 minutes so it can recalibrate to take account of natural changes in background humidity. A humidity increase of 2% is needed to blow out the candle, so if the background humidity changes by more than 2% in 15 minutes, it’s possible to get a false positive. Press Ctrl + C to quit.

Please tweet pictures of your candles to @astro_pi – we might share yours! And if we’re lucky, we might catch a glimpse of the candle on the ISS during the NASA TV event at 16:30 GMT today.

The post Astro Pi celebrates anniversary of ISS Columbus module appeared first on Raspberry Pi.

MusE 3.0.0 released

Post Syndicated from ris original https://lwn.net/Articles/743598/rss

Three years after the last stable release, version 3.0 of the MusE
MIDI/Audio sequencer is now available. As you might expect there many
changes since the last release including a switch to Qt5, a new Plugin Path
editor in Global Settings, a mixer makeover with lots of fixes, a
system-wide move to double precision of all audio paths, and much more.

Security updates for Friday

Post Syndicated from jake original https://lwn.net/Articles/743242/rss

Security updates have been issued by Arch Linux (kernel), CentOS (kernel, libvirt, microcode_ctl, and qemu-kvm), Debian (kernel and xen), Fedora (kernel), Mageia (backintime, erlang, and wildmidi), openSUSE (kernel and ucode-intel), Oracle (kernel, libvirt, microcode_ctl, and qemu-kvm), Red Hat (kernel, kernel-rt, libvirt, microcode_ctl, qemu-kvm, and qemu-kvm-rhev), Scientific Linux (libvirt and qemu-kvm), SUSE (kvm and qemu), and Ubuntu (ruby1.9.1, ruby2.0, ruby2.3).

MagPi 65: Newbies Guide, and something brand new!

Post Syndicated from Rob Zwetsloot original https://www.raspberrypi.org/blog/magpi-65/

Hey folks, Rob from The MagPi here! We know many people might be getting their very first Raspberry Pi this Christmas, and excitedly wondering “what do I do with it?” While we can’t tell you exactly what to do with your Pi, we can show you how to immerse yourself in the world of Raspberry Pi and be inspired by our incredible community, and that’s the topic of The MagPi 65, out today tomorrow (we’re a day early because we’re simply TOO excited about the special announcement below!).

The one, the only…issue 65!

Raspberry Pi for Newbies

Raspberry Pi for Newbies covers some of the very basics you should know about the world of Raspberry Pi. After a quick set-up tutorial, we introduce you to the Raspberry Pi’s free online resources, including Scratch and Python projects from Code Club, before guiding you through the wider Raspberry Pi and maker community.

Raspberry Pi MagPi 65 Newbie Guide

Pages and pages of useful advice and starter projects

The online community is an amazing place to learn about all the incredible things you can do with the Raspberry Pi. We’ve included some information on good places to look for tutorials, advice and ideas.

And that’s not all

Want to do more after learning about the world of Pi? The rest of the issue has our usual selection of expert guides to help you build some amazing projects: you can make a Christmas memory game, build a tower of bells to ring in the New Year, and even take your first steps towards making a game using C++.

Raspberry Pi MagPi 65

Midimutant, the synthesizer “that boinks endless strange sounds”

All this along with inspiring projects, definitive reviews, and tales from around the community.

Raspberry Pi Annual

Issue 65 isn’t the only new release to look out for. We’re excited to bring you the first ever Raspberry Pi Annual, and it’s free for MagPi subscribers – in fact, subscribers should be receiving it the same day as their issue 65 delivery!

If you’re not yet a subscriber of The MagPi, don’t panic: you can still bag yourself a copy of the Raspberry Pi Annual by signing up to a 12-month subscription of The MagPi before 24 January. You’ll also receive the usual subscriber gift of a free Raspberry Pi Zero W (with case and cable).  Click here to subscribe to The MagPi – The Official Raspberry Pi magazine.


The Raspberry Pi Annual is aimed at young folk wanting to learn to code, with a variety of awesome step-by-step Scratch tutorials, games, puzzles, and comics, including a robotic Babbage.

Get your copy

You can get The MagPi 65 and the Raspberry Pi Annual 2018 from our online store, and the magazine can be found in the wild at WHSmith, Tesco, Sainsbury’s, and Asda. You’ll be able to get it in the US at Barnes & Noble and Micro Center in a few days’ time. The MagPi 65 is also available digitally on our Android and iOS apps. Finally, you can also download a free PDF of The MagPi 65 and The Raspberry Pi Annual 2018.

We hope you have a merry Christmas! We’re off until the New Year. Bye!

The post MagPi 65: Newbies Guide, and something brand new! appeared first on Raspberry Pi.

All the lights, all of the twinkly lights

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/all-of-the-lights/

Twinkly lights are to Christmas what pumpkins are to Halloween. And when you add a Raspberry Pi to your light show, the result instantly goes from “Meh, yeah.” to “OMG, wow!”

Here are some cool light-based Christmas projects to inspire you this weekend.

Raspberry Pi Christmas Lights

App-based light control

Christmas Tree Lights Demo

Project Code – https://github.com/eidolonFIRE/Christmas-Lights Raspberry Pi A+ ws2812b – https://smile.amazon.com/gp/product/B01H04YAIQ/ref=od_aui_detailpages00?ie=UTF8&psc=1 200w 5V supply – https://smile.amazon.com/gp/product/B01LZRIWZD/ref=od_aui_detailpages01?ie=UTF8&psc=1

In his Christmas lights project, Caleb Johnson uses an app as a control panel to switch between predefined displays. The full code is available on his GitHub, and it connects a Raspberry Pi A+ to a strip of programmable LEDs that change their pattern at the touch of a phone screen.

What’s great about this project, aside from the simplicity of its design, is the scope for extending it. Why not share the app with friends and family, allowing them to control your lights remotely? Or link the lights to social media so they are triggered by a specific hashtag, like in Alex Ellis’ #cheerlights project below.

Worldwide holiday #cheerlights

Holiday lights hack – 1$ Snowman + Raspberry Pi

Here we have a smart holiday light which will only run when it detects your presence in the room through a passive infrared PIR sensor. I’ve used hot glue for the fixings and an 8-LED NeoPixel strip connected to port 18.

Cheerlights, an online service created by Hans Scharler, allows makers to incorporate hashtag-controlled lighting into the projects. By tweeting the hashtag #cheerlights, followed by a colour, you can control a network of lights so that they are all displaying the same colour.

For his holiday light hack using Cheerlights, Alex incorporated the Pimoroni Blinkt! and a collection of cheap Christmas decorations to create cute light-up ornaments for the festive season.

To make your own, check out Alex’s blog post, and head to your local £1/$1 store for hackable decor. You could even link your Christmas tree and the trees of your family, syncing them all in one glorious, Santa-pleasing spectacular.

Outdoor decorations

DIY musical Xmas lights for beginners with raspberry pi

With just a few bucks of extra material, I walk you through converting your regular Christmas lights into a whole-house light show. The goal here is to go from scratch. Although this guide is intended for people who don’t know how to use linux at all and those who do alike, the focus is for people for whom linux and the raspberry pi are a complete mystery.

Looking to outdo your neighbours with your Christmas light show this year? YouTuber Makin’Things has created a beginners guide to setting up a Raspberry Pi–based musical light show for your facade, complete with information on soldering, wiring, and coding.

Once you’ve wrapped your house in metres and metres of lights and boosted your speakers so they can be heard for miles around, why not incorporate #cheerlights to make your outdoor decor interactive?

Still not enough? How about controlling your lights using a drum kit? Christian Kratky’s MIDI-Based Christmas Lights Animation system (or as I like to call it, House Rock) does exactly that.

Eye Of The Tiger (MIDI based christmas lights animation system prototype)

Project documentation and source code: https://www.hackster.io/cyborg-titanium-14/light-pi-1c88b0 The song is taken from: https://www.youtube.com/watch?v=G6r1dAire0Y

Any more?

We know these projects are just the tip of the iceberg when it comes to the Raspberry Pi–powered Christmas projects out there, and as always, we’d love you to share yours with us. So post a link in the comments below, or tag us on social media when posting your build photos, videos, and/or blog links. ‘Tis the season for sharing after all.

The post All the lights, all of the twinkly lights appeared first on Raspberry Pi.

Security updates for Monday

Post Syndicated from ris original https://lwn.net/Articles/741158/rss

Security updates have been issued by CentOS (postgresql), Debian (firefox-esr, kernel, libxcursor, optipng, thunderbird, wireshark, and xrdp), Fedora (borgbackup, ca-certificates, collectd, couchdb, curl, docker, erlang-jiffy, fedora-arm-installer, firefox, git, linux-firmware, mupdf, openssh, thunderbird, transfig, wildmidi, wireshark, xen, and xrdp), Mageia (firefox and optipng), openSUSE (erlang, libXfont, and OBS toolchain), Oracle (kernel), Slackware (openssl), and SUSE (kernel and OBS toolchain).

In the Works – AWS IoT Device Defender – Secure Your IoT Fleet

Post Syndicated from Jeff Barr original https://aws.amazon.com/blogs/aws/in-the-works-aws-sepio-secure-your-iot-fleet/

Scale takes on a whole new meaning when it comes to IoT. Last year I was lucky enough to tour a gigantic factory that had, on average, one environment sensor per square meter. The sensors measured temperature, humidity, and air purity several times per second, and served as an early warning system for contaminants. I’ve heard customers express interest in deploying IoT-enabled consumer devices in the millions or tens of millions.

With powerful, long-lived devices deployed in a geographically distributed fashion, managing security challenges is crucial. However, the limited amount of local compute power and memory can sometimes limit the ability to use encryption and other forms of data protection.

To address these challenges and to allow our customers to confidently deploy IoT devices at scale, we are working on IoT Device Defender. While the details might change before release, AWS IoT Device Defender is designed to offer these benefits:

Continuous AuditingAWS IoT Device Defender monitors the policies related to your devices to ensure that the desired security settings are in place. It looks for drifts away from best practices and supports custom audit rules so that you can check for conditions that are specific to your deployment. For example, you could check to see if a compromised device has subscribed to sensor data from another device. You can run audits on a schedule or on an as-needed basis.

Real-Time Detection and AlertingAWS IoT Device Defender looks for and quickly alerts you to unusual behavior that could be coming from a compromised device. It does this by monitoring the behavior of similar devices over time, looking for unauthorized access attempts, changes in connection patterns, and changes in traffic patterns (either inbound or outbound).

Fast Investigation and Mitigation – In the event that you get an alert that something unusual is happening, AWS IoT Device Defender gives you the tools, including contextual information, to help you to investigate and mitigate the problem. Device information, device statistics, diagnostic logs, and previous alerts are all at your fingertips. You have the option to reboot the device, revoke its permissions, reset it to factory defaults, or push a security fix.

Stay Tuned
I’ll have more info (and a hands-on post) as soon as possible, so stay tuned!


Visualising Weather Station data with Initial State

Post Syndicated from Richard Hayler original https://www.raspberrypi.org/blog/initial-state/

Since we launched the Oracle Weather Station project, we’ve collected more than six million records from our network of stations at schools and colleges around the world. Each one of these records contains data from ten separate sensors — that’s over 60 million individual weather measurements!

Weather station measurements in Oracle database - Initial State

Weather station measurements in Oracle database

Weather data collection

Having lots of data covering a long period of time is great for spotting trends, but to do so, you need some way of visualising your measurements. We’ve always had great resources like Graphing the weather to help anyone analyse their weather data.

And from now on its going to be even easier for our Oracle Weather Station owners to display and share their measurements. I’m pleased to announce a new partnership with our friends at Initial State: they are generously providing a white-label platform to which all Oracle Weather Station recipients can stream their data.

Using Initial State

Initial State makes it easy to create vibrant dashboards that show off local climate data. The service is perfect for having your Oracle Weather Station data on permanent display, for example in the school reception area or on the school’s website.

But that’s not all: the Initial State toolkit includes a whole range of easy-to-use analysis tools for extracting trends from your data. Distribution plots and statistics are just a few clicks away!

Humidity value distribution (May-Nov 2017) - Raspberry Pi Oracle Weather Station Initial State

Looks like Auntie Beryl is right — it has been a damp old year! (Humidity value distribution May–Nov 2017)

The wind direction data from my Weather Station supports my excuse as to why I’ve not managed a high-altitude balloon launch this year: to use my launch site, I need winds coming from the east, and those have been in short supply.

Chart showing wind direction over time - Raspberry Pi Oracle Weather Station Initial State

Chart showing wind direction over time

Initial State credientials

Every Raspberry Pi Oracle Weather Station school will shortly be receiving the credentials needed to start streaming their data to Initial State. If you’re super keen though, please email [email protected] with a photo of your Oracle Weather Station, and I’ll let you jump the queue!

The Initial State folks are big fans of Raspberry Pi and have a ton of Pi-related projects on their website. They even included shout-outs to us in the music video they made to celebrate the publication of their 50th tutorial. Can you spot their weather station?

Your home-brew weather station

If you’ve built your own Raspberry Pi–powered weather station and would like to dabble with the Initial State dashboards, you’re in luck! The team at Initial State is offering 14-day trials for everyone. For more information on Initial State, and to sign up for the trial, check out their website.

The post Visualising Weather Station data with Initial State appeared first on Raspberry Pi.

Using taxies to monitor air quality in Peru

Post Syndicated from Alex Bate original https://www.raspberrypi.org/blog/air-quality-peru/

When James Puderer moved to Lima, Peru, his roadside runs left a rather nasty taste in his mouth. Hit by the pollution from old diesel cars in the area, he decided to monitor the air quality in his new city using Raspberry Pis and the abundant taxies as his tech carriers.

Taxi Datalogger – Assembly

How to assemble the enclosure for my Taxi Datalogger project: https://www.hackster.io/james-puderer/distributed-air-quality-monitoring-using-taxis-69647e

Sensing air quality in Lima

Luckily for James, almost all taxies in Lima are equipped with the standard hollow vinyl roof sign seen in the video above, which makes them ideal for hacking.

Using a Raspberry Pi alongside various Adafuit tech including the BME280 Temperature/Humidity/Pressure Sensor and GPS Antenna, James created a battery-powered retrofit setup that fits snugly into the vinyl sign.

The schematic of the air quality monitor tech inside the taxi sign

With the onboard tech, the device collects data on longitude, latitude, humidity, temperature, pressure, and airborne particle count, feeding it back to an Android Things datalogger. This data is then pushed to Google IoT Core, where it can be remotely accessed.

Next, the data is processed by Google Dataflow and turned into a BigQuery table. Users can then visualize the collected measurements. And while James uses Google Maps to analyse his data, there are many tools online that will allow you to organise and study your figures depending on what final result you’re hoping to achieve.

A heat map of James' local area showing air quality

James hopped in a taxi and took his monitor on the road, collecting results throughout the journey

James has provided the complete build process, including all tech ingredients and code, on his Hackster.io project page, and urges makers to create their own air quality monitor for their local area. He also plans on building upon the existing design by adding a 12V power hookup for connecting to the taxi, functioning lights within the sign, and companion apps for drivers.

Sensing the world around you

We’ve seen a wide variety of Raspberry Pi projects using sensors to track the world around us, such as Kasia Molga’s Human Sensor costume series, which reacts to air pollution by lighting up, and Clodagh O’Mahony’s Social Interaction Dress, which she created to judge how conversation and physical human interaction can be scored and studied.

Human Sensor

Kasia Molga’s Human Sensor — a collection of hi-tech costumes that react to air pollution within the wearer’s environment.

Many people also build their own Pi-powered weather stations, or use the Raspberry Pi Oracle Weather Station, to measure and record conditions in their towns and cities from the roofs of schools, offices, and homes.

Have you incorporated sensors into your Raspberry Pi projects? Share your builds in the comments below or via social media by tagging us.

The post Using taxies to monitor air quality in Peru appeared first on Raspberry Pi.

MagPi 63: build the arcade cabinet of your dreams

Post Syndicated from Rob Zwetsloot original https://www.raspberrypi.org/blog/magpi-63/

Hi folks, Rob from The MagPi here! Issue 63 is now available, and it’s a huge one: we finally show you how to create the ultimate Raspberry Pi arcade cabinet in our latest detailed tutorial, so get some quarters and your saw ready.

MagPi 63

Totally awesome video game builds!

The 16-page-long arcade machine instructions cover everything from the tools you need and how to do the woodwork, to setting up the electronics. In my spare time, I pretend to be Street Fighter baddie M. Bison, so I’m no stranger to arcade machines. However, I had never actually built one — luckily, the excellent Bob Clagett of I Like To Make Stuff was generous enough to help out with this project. I hope you enjoy reading the article, and making your own cabinet, as much as I enjoyed writing and building them.

Projects for kids

Retro gaming isn’t the only thing you’ll find in this issue of The MagPi though. We have a big feature called Junior Pi Projects, which we hope will inspire young people to make something really cool using Scratch or Python.

As usual, the new issue also includes a collection of other tutorials for you to follow, for example for building a hydroponic garden, or making a special MIDI box. There are also fantastic maker projects to read up on, and reviews to tempt your wallet.

MagPi 63

The kids are alright

Get The MagPi 63

You can grab The MagPi 63 right now from WH Smith, Tesco, Sainsbury’s, and Asda. If you live in the US, check out your local Barnes & Noble or Micro Center in the next few days. You can also get the new issue online from our store, or digitally via our Android or iOS apps. And don’t forget, there’s always the free PDF as well.

Subscribe for free goodies

Want to support the Raspberry Pi Foundation, the magazine, and get some cool free stuff? If you take out a twelve-month print subscription to The MagPi, you’ll get a Pi Zero W, Pi Zero case, and adapter cables absolutely free! This offer does not currently have an end date.

That’s it for this month! We’re off to play some games.

The post MagPi 63: build the arcade cabinet of your dreams appeared first on Raspberry Pi.

The possibilities of the Sense HAT

Post Syndicated from Janina Ander original https://www.raspberrypi.org/blog/sense-hat-projects/

Did you realise the Sense HAT has been available for over two years now? Used by astronauts on the International Space Station, the exact same hardware is available to you on Earth. With a new Astro Pi challenge just launched, it’s time for a retrospective/roundup/inspiration post about this marvellous bit of kit.

Sense HAT attached to Pi and power cord

The Sense HAT on a Pi in full glory

The Sense HAT explained

We developed our scientific add-on board to be part of the Astro Pi computers we sent to the International Space Station with ESA astronaut Tim Peake. For a play-by-play of Astro Pi’s history, head to the blog archive.

Astro Pi logo with starry background

Just to remind you, this is all the cool stuff our engineers have managed to fit onto the HAT:

  • A gyroscope (sensing pitch, roll, and yaw)
  • An accelerometer
  • A magnetometer
  • Sensors for temperature, humidity, and barometric pressure
  • A joystick
  • An 8×8 LED matrix

You can find a roundup of the technical specs here on the blog.

How to Sense HAT

It’s easy to begin exploring this device: take a look at our free Getting started with the Sense HAT resource, or use one of our Code Club Sense HAT projects. You can also try out the emulator, available offline on Raspbian and online on Trinket.

Sense HAT emulator on Trinket

The Sense HAT emulator on trinket.io

Fun and games with the Sense HAT

Use the LED matrix and joystick to recreate games such as Pong or Flappy Bird. Of course, you could also add sensor input to your game: code an egg drop game or a Magic 8 Ball that reacts to how the device moves.

Sense HAT Random Sparkles

Create random sparkles on the Sense HAT

Once December rolls around, you could brighten up your home with a voice-controlled Christmas tree or an advent calendar on your Sense HAT.

If you like the great outdoors, you could also use your Sense HAT to recreate this Hiking Companion by Marcus Johnson. Take it with you on your next hike!

Art with the Sense HAT

The LED matrix is perfect for getting creative. To draw something basic without having to squint at a Python list, use this app by our very own Richard Hayler. Feeling more ambitious? The MagPi will teach you how to create magnificent pixel art. Ben Nuttall has created this neat little Python script for displaying a photo taken by the Raspberry Pi Camera Module on the Sense HAT.

Brett Haines Mathematica on the Sense HAT

It’s also possible to incorporate Sense HAT data into your digital art! The Python Turtle module and the Processing language are both useful tools for creating beautiful animations based on real-world information.

A Sense HAT project that also uses this principle is Giorgio Sancristoforo’s Tableau, a ‘generative music album’. This device creates music according to the sensor data:

Tableau Generative Album

“There is no doubt that, as music is removed by the phonographrecord from the realm of live production and from the imperative of artistic activity and becomes petrified, it absorbs into itself, in this process of petrification, the very life that would otherwise vanish.”

Science with the Sense HAT

This free Essentials book from The MagPi team covers all the Sense HAT science basics. You can, for example, learn how to measure gravity.

Cropped cover of Experiment with the Sense HAT book

Our online resource shows you how to record the information your HAT picks up. Next you can analyse and graph your data using Mathematica, which is included for free on Raspbian. This resource walks you through how this software works.

If you’re seeking inspiration for experiments you can do on our Astro Pis Izzy and Ed on the ISS, check out the winning entries of previous rounds of the Astro Pi challenge.

Thomas Pesquet with Ed and Izzy

Thomas Pesquet with Ed and Izzy

But you can also stick to terrestrial scientific investigations. For example, why not build a weather station and share its data on your own web server or via Weather Underground?

Your code in space!

If you’re a student or an educator in one of the 22 ESA member states, you can get a team together to enter our 2017-18 Astro Pi challenge. There are two missions to choose from, including Mission Zero: follow a few guidelines, and your code is guaranteed to run in space!

The post The possibilities of the Sense HAT appeared first on Raspberry Pi.

Ultrasonic pi-ano

Post Syndicated from Janina Ander original https://www.raspberrypi.org/blog/ultrasonic-piano/

At the Raspberry Pi Foundation, we love a good music project. So of course we’re excited to welcome Andy Grove‘s ultrasonic piano to the collection! It is a thing of beauty… and noise. Don’t let the name fool you – this build can do so much more than sound like a piano.

Ultrasonic Pi Piano – Full Demo

The Ultrasonic Pi Piano uses HC-SR04 ultrasonic sensors for input and generates MIDI instructions that are played by fluidsynth. For more information: http://theotherandygrove.com/projects/ultrasonic-pi-piano/

What’s an ultrasonic piano?

What we have here, people of all genders, is really a theremin on steroids. The build’s eight ultrasonic distance sensors detect hand movements and, with the help of an octasonic breakout board, a Raspberry Pi 3 translates their signals into notes. But that’s not all: this digital instrument is almost endlessly customisable – you can set each sensor to a different octave, or to a different instrument.

octasonic breakout board

The breakout board designed by Andy

Andy has implemented gesture controls to allow you to switch between modes you have preset. In his video, you can see that holding your hands over the two sensors most distant from each other changes the instrument. Say you’re bored of the piano – try a xylophone! Not your jam? How about a harpsichord? Or a clarinet? In fact, there are 128 MIDI instruments and sound effects to choose from. Go nuts and compose a piece using tuba, ocarina, and the noise of a guitar fret!

How to build the ultrasonic piano

If you head over to Instructables, you’ll find the thorough write-up Andy has provided. He has also made all his scripts, written in Rust, available on GitHub. Finally, he’s even added a video on how to make a housing, so your ultrasonic piano can look more like a proper instrument, and less like a pile of electronics.

Ultrasonic Pi Piano Enclosure

Uploaded by Andy Grove on 2017-04-13.

Make your own!

If you follow us on Twitter, you may have seen photos and footage of the Raspberry Pi staff attending a Pi Towers Picademy. Like Andy*, quite a few of us are massive Whovians. Consequently, one of our final builds on the course was an ultrasonic theremin that gave off a sound rather like a dying Dalek. Take a look at our masterwork here! We loved our make so much that we’ve since turned the instructions for building it into a free resource. Go ahead and build your own! And be sure to share your compositions with us in the comments.

Sonic the hedgehog is feeling the beat

Sonic is feeling the groove as well

* He has a full-sized Dalek at home. I know, right?

The post Ultrasonic pi-ano appeared first on Raspberry Pi.

A Guide Through The Linux Sound API Jungle

Post Syndicated from Lennart Poettering original http://0pointer.net/blog/projects/guide-to-sound-apis.html

At the Audio MC at the Linux Plumbers Conference one
thing became very clear: it is very difficult for programmers to
figure out which audio API to use for which purpose and which API not
to use when doing audio programming on Linux. So here’s my try to
guide you through this jungle:

What do you want to do?

I want to write a media-player-like application!
Use GStreamer! (Unless your focus is only KDE in which cases Phonon might be an alternative.)
I want to add event sounds to my application!
Use libcanberra, install your sound files according to the XDG Sound Theming/Naming Specifications! (Unless your focus is only KDE in which case KNotify might be an alternative although it has a different focus.)
I want to do professional audio programming, hard-disk recording, music synthesizing, MIDI interfacing!
Use JACK and/or the full ALSA interface.
I want to do basic PCM audio playback/capturing!
Use the safe ALSA subset.
I want to add sound to my game!
Use the audio API of SDL for full-screen games, libcanberra for simple games with standard UIs such as Gtk+.
I want to write a mixer application!
Use the layer you want to support directly: if you want to support enhanced desktop software mixers, use the PulseAudio volume control APIs. If you want to support hardware mixers, use the ALSA mixer APIs.
I want to write audio software for the plumbing layer!
Use the full ALSA stack.
I want to write audio software for embedded applications!
For technical appliances usually the safe ALSA subset is a good choice, this however depends highly on your use-case.

You want to know more about the different sound APIs?

GStreamer is the de-facto
standard media streaming system for Linux desktops. It supports decoding and
encoding of audio and video streams. You can use it for a wide range of
purposes from simple audio file playback to elaborate network
streaming setups. GStreamer supports a wide range of CODECs and audio
backends. GStreamer is not particularly suited for basic PCM playback
or low-latency/realtime applications. GStreamer is portable and not
limited in its use to Linux. Among the supported backends are ALSA, OSS, PulseAudio. [Programming Manuals and References]
is an abstract event sound API. It implements the XDG
Sound Theme and Naming Specifications
. libcanberra is a blessed
GNOME dependency, but itself has no dependency on GNOME/Gtk/GLib and can be
used with other desktop environments as well. In addition to an easy
interface for playing sound files, libcanberra provides caching
(which is very useful for networked thin clients) and allows passing
of various meta data to the underlying audio system which then can be
used to enhance user experience (such as positional event sounds) and
for improving accessibility. libcanberra supports multiple backends
and is portable beyond Linux. Among the supported backends are ALSA, OSS, PulseAudio, GStreamer. [API Reference]
JACK is a sound system for
connecting professional audio production applications and hardware
output. It’s focus is low-latency and application interconnection. It
is not useful for normal desktop or embedded use. It is not an API
that is particularly useful if all you want to do is simple PCM
playback. JACK supports multiple backends, although ALSA is best
supported. JACK is portable beyond Linux. Among the supported backends are ALSA, OSS. [API Reference]
ALSA is the Linux API
for doing PCM playback and recording. ALSA is very focused on
hardware devices, although other backends are supported as well (to a
limit degree, see below). ALSA as a name is used both for the Linux
audio kernel drivers and a user-space library that wraps these. ALSA — the library — is
comprehensive, and portable (to a limited degree). The full ALSA API
can appear very complex and is large. However it supports almost
everything modern sound hardware can provide. Some of the
functionality of the ALSA API is limited in its use to actual hardware
devices supported by the Linux kernel (in contrast to software sound
servers and sound drivers implemented in user-space such as those for
Bluetooth and FireWire audio — among others) and Linux specific
drivers. [API
Only a subset of the full ALSA API works on all backends ALSA
supports. It is highly recommended to stick to this safe subset
if you do ALSA programming to keep programs portable, future-proof and
compatible with sound servers, Bluetooth audio and FireWire audio. See
below for more details about which functions of ALSA are considered
safe. The safe ALSA API is a suitable abstraction for basic,
portable PCM playback and recording — not just for ALSA kernel driver
supported devices. Among the supported backends are ALSA kernel driver
devices, OSS, PulseAudio, JACK.
Phonon and KNotify
Phonon is high-level
abstraction for media streaming systems such as GStreamer, but goes a
bit further than that. It supports multiple backends. KNotify is a
system for “notifications”, which goes beyond mere event
sounds. However it does not support the XDG Sound Theming/Naming
Specifications at this point, and also doesn’t support caching or
passing of event meta-data to an underlying sound system. KNotify
supports multiple backends for audio playback via Phonon. Both APIs
are KDE/Qt specific and should not be used outside of KDE/Qt
applications. [Phonon API Reference] [KNotify API Reference]
SDL is a portable API
primarily used for full-screen game development. Among other stuff it
includes a portable audio interface. Among others SDL support OSS,
PulseAudio, ALSA as backends. [API Reference]
PulseAudio is a sound system
for Linux desktops and embedded environments that runs in user-space
and (usually) on top of ALSA. PulseAudio supports network
transparency, per-application volumes, spatial events sounds, allows
switching of sound streams between devices on-the-fly, policy
decisions, and many other high-level operations. PulseAudio adds a glitch-free
audio playback model to the Linux audio stack. PulseAudio is not
useful in professional audio production environments. PulseAudio is
portable beyond Linux. PulseAudio has a native API and also supports
the safe subset of ALSA, in addition to limited,
LD_PRELOAD-based OSS compatibility. Among others PulseAudio supports
OSS and ALSA as backends and provides connectivity to JACK. [API
The Open Sound System is a
low-level PCM API supported by a variety of Unixes including Linux. It
started out as the standard Linux audio system and is supported on
current Linux kernels in the API version 3 as OSS3. OSS3 is considered
obsolete and has been fully replaced by ALSA. A successor to OSS3
called OSS4 is available but plays virtually no role on Linux and is
not supported in standard kernels or by any of the relevant
distributions. The OSS API is very low-level, based around direct
kernel interfacing using ioctl()s. It it is hence awkward to use and
can practically not be virtualized for usage on non-kernel audio
systems like sound servers (such as PulseAudio) or user-space sound
drivers (such as Bluetooth or FireWire audio). OSS3’s timing model
cannot properly be mapped to software sound servers at all, and is
also problematic on non-PCI hardware such as USB audio. Also, OSS does
not do sample type conversion, remapping or resampling if
necessary. This means that clients that properly want to support OSS
need to include a complete set of converters/remappers/resamplers for
the case when the hardware does not natively support the requested
sampling parameters. With modern sound cards it is very common to
support only S32LE samples at 48KHz and nothing else. If an OSS client
assumes it can always play back S16LE samples at 44.1KHz it will thus
fail. OSS3 is portable to other Unix-like systems, various differences
however apply. OSS also doesn’t support surround sound and other
functionality of modern sounds systems properly. OSS should be
considered obsolete and not be used in new applications.
ALSA and
PulseAudio have limited LD_PRELOAD-based compatibility with OSS. [Programming Guide]

All sound systems and APIs listed above are supported in all
relevant current distributions. For libcanberra support the newest
development release of your distribution might be necessary.

All sound systems and APIs listed above are suitable for
development for commercial (read: closed source) applications, since
they are licensed under LGPL or more liberal licenses or no client
library is involved.

You want to know why and when you should use a specific sound API?

GStreamer is best used for very high-level needs: i.e. you want to
play an audio file or video stream and do not care about all the tiny
details down to the PCM or codec level.
libcanberra is best used when adding sound feedback to user input
in UIs. It can also be used to play simple sound files for
notification purposes.
JACK is best used in professional audio production and where interconnecting applications is required.
The full ALSA interface is best used for software on “plumbing layer” or when you want to make use of very specific hardware features, which might be need for audio production purposes.
The safe ALSA interface is best used for software that wants to output/record basic PCM data from hardware devices or software sound systems.
Phonon and KNotify
Phonon and KNotify should only be used in KDE/Qt applications and only for high-level media playback, resp. simple audio notifications.
SDL is best used in full-screen games.
For now, the PulseAudio API should be used only for applications
that want to expose sound-server-specific functionality (such as
mixers) or when a PCM output abstraction layer is already available in
your application and it thus makes sense to add an additional backend
to it for PulseAudio to keep the stack of audio layers minimal.
OSS should not be used for new programs.

You want to know more about the safe ALSA subset?

Here’s a list of DOS and DONTS in the ALSA API if you care about
that you application stays future-proof and works fine with
non-hardware backends or backends for user-space sound drivers such as
Bluetooth and FireWire audio. Some of these recommendations apply for
people using the full ALSA API as well, since some functionality
should be considered obsolete for all cases.

If your application’s code does not follow these rules, you must have
a very good reason for that. Otherwise your code should simply be considered


  • Do not use “async handlers”, e.g. via
    snd_async_add_pcm_handler() and friends. Asynchronous
    handlers are implemented using POSIX signals, which is a very
    questionable use of them, especially from libraries and plugins. Even
    when you don’t want to limit yourself to the safe ALSA subset
    it is highly recommended not to use this functionality. Read
    this for a longer explanation why signals for audio IO are
  • Do not parse the ALSA configuration file yourself or with
    any of the ALSA functions such as snd_config_xxx(). If you
    need to enumerate audio devices use snd_device_name_hint()
    (and related functions). That
    is the only API that also supports enumerating non-hardware audio
    devices and audio devices with drivers implemented in userspace.
  • Do not parse any of the files from
    /proc/asound/. Those files only include information about
    kernel sound drivers — user-space plugins are not listed there. Also,
    the set of kernel devices might differ from the way they are presented
    in user-space. (i.e. sub-devices are mapped in different ways to
    actual user-space devices such as surround51 an suchlike.
  • Do not rely on stable device indexes from ALSA. Nowadays
    they depend on the initialization order of the drivers during boot-up
    time and are thus not stable.
  • Do not use the snd_card_xxx() APIs. For
    enumerating use snd_device_name_hint() (and related
    functions). snd_card_xxx() is obsolete. It will only list
    kernel hardware devices. User-space devices such as sound servers,
    Bluetooth audio are not included. snd_card_load() is
    completely obsolete in these days.
  • Do not hard-code device strings, especially not
    hw:0 or plughw:0 or even dmix — these devices define no channel
    mapping and are mapped to raw kernel devices. It is highly recommended
    to use exclusively default as device string. If specific
    channel mappings are required the correct device strings should be
    front for stereo, surround40 for Surround 4.0,
    surround41, surround51, and so on. Unfortunately at
    this point ALSA does not define standard device names with channel
    mappings for non-kernel devices. This means default may only
    be used safely for mono and stereo streams. You should probably prefix
    your device string with plug: to make sure ALSA transparently
    reformats/remaps/resamples your PCM stream for you if the
    hardware/backend does not support your sampling parameters
  • Do not assume that any particular sample type is supported
    except the following ones: U8, S16_LE, S16_BE, S32_LE, S32_BE,
  • Do not use snd_pcm_avail_update() for
    synchronization purposes. It should be used exclusively to query the
    amount of bytes that may be written/read right now. Do not use
    snd_pcm_delay() to query the fill level of your playback
    buffer. It should be used exclusively for synchronisation
    purposes. Make sure you fully understand the difference, and note that
    the two functions return values that are not necessarily directly
  • Do not assume that the mixer controls always know dB information.
  • Do not assume that all devices support MMAP style buffer access.
  • Do not assume that the hardware pointer inside the (possibly mmaped) playback buffer is the actual position of the sample in the DAC. There might be an extra latency involved.
  • Do not try to recover with your own code from ALSA error conditions such as buffer under-runs. Use snd_pcm_recover() instead.
  • Do not touch buffering/period metrics unless you have
    specific latency needs. Develop defensively, handling correctly the
    case when the backend cannot fulfill your buffering metrics
    requests. Be aware that the buffering metrics of the playback buffer
    only indirectly influence the overall latency in many
    cases. i.e. setting the buffer size to a fixed value might actually result in
    practical latencies that are much higher.
  • Do not assume that snd_pcm_rewind() is available and works and to which degree.
  • Do not assume that the time when a PCM stream can receive
    new data is strictly dependant on the sampling and buffering
    parameters and the resulting average throughput. Always make sure to
    supply new audio data to the device when it asks for it by signalling
    “writability” on the fd. (And similarly for capturing)
  • Do not use the “simple” interface snd_spcm_xxx().
  • Do not use any of the functions marked as “obsolete”.
  • Do not use the timer, midi, rawmidi, hwdep subsystems.


  • Use snd_device_name_hint() for enumerating audio devices.
  • Use snd_smixer_xx() instead of raw snd_ctl_xxx()
  • For synchronization purposes use snd_pcm_delay().
  • For checking buffer playback/capture fill level use snd_pcm_update_avail().
  • Use snd_pcm_recover() to recover from errors returned by any of the ALSA functions.
  • If possible use the largest buffer sizes the device supports to maximize power saving and drop-out safety. Use snd_pcm_rewind() if you need to react to user input quickly.


What about ESD and NAS?
ESD and NAS are obsolete, both as API and as sound daemon. Do not develop for it any further.
ALSA isn’t portable!
That’s not true! Actually the user-space library is relatively portable, it even includes a backend for OSS sound devices. There is no real reason that would disallow using the ALSA libraries on other Unixes as well.
Portability is key to me! What can I do?
Unfortunately no truly portable (i.e. to Win32) PCM API is
available right now that I could truly recommend. The systems shown
above are more or less portable at least to Unix-like operating
systems. That does not mean however that there are suitable backends
for all of them available. If you care about portability to Win32 and
MacOS you probably have to find a solution outside of the
recommendations above, or contribute the necessary
backends/portability fixes. None of the systems (with the exception of
OSS) is truly bound to Linux or Unix-like kernels.
What about PortAudio?
I don’t think that PortAudio is very good API for Unix-like operating systems. I cannot recommend it, but it’s your choice.
Oh, why do you hate OSS4 so much?
I don’t hate anything or anyone. I just don’t think OSS4 is a
serious option, especially not on Linux. On Linux, it is also
completely redundant due to ALSA.
You idiot, you have no clue!
You are right, I totally don’t. But that doesn’t hinder me from recommending things. Ha!
Hey I wrote/know this tiny new project which is an awesome abstraction layer for audio/media!
Sorry, that’s not sufficient. I only list software here that is known to be sufficiently relevant and sufficiently well maintained.

Final Words

Of course these recommendations are very basic and are only intended to
lead into the right direction. For each use-case different necessities
apply and hence options that I did not consider here might become
viable. It’s up to you to decide how much of what I wrote here
actually applies to your application.

This summary only includes software systems that are considered
stable and universally available at the time of writing. In the
future I hope to introduce a more suitable and portable replacement
for the safe ALSA subset of functions. I plan to update this text
from time to time to keep things up-to-date.

If you feel that I forgot a use case or an important API, then
please contact me or leave a comment. However, I think the summary
above is sufficiently comprehensive and if an entry is missing I most
likely deliberately left it out.

(Also note that I am upstream for both PulseAudio and libcanberra and did some minor contributions to ALSA, GStreamer and some other of the systems listed above. Yes, I am biased.)

Oh, and please syndicate this, digg it. I’d like to see this guide to be well-known all around the Linux community. Thank you!