A hanging plotter, also known as a polar plotter or polargraph, is a machine for drawing images on a vertical surface. It does so by using motors to control the length of two cords that form a V shape, supporting a pen where they meet. We’ve featured one on this blog before: Norbert “HomoFaciens” Heinz’s video is a wonderfully clear introduction to how a polargraph works and what you have to consider when you’re putting one together.
Today, we look at Inky Lines, by John Proudlock. With it, John is creating a series of captivating and beautiful pieces, and with his most recent work, each rendering of an image is unique.
An evolving project
The project isn’t new – John has been working on it for at least a couple of years – but it is constantly evolving. When we first spotted it, John had just implemented code to allow the plotter to produce mesmeric, spiralling patterns.
But we’re skipping ahead. Let’s go back to the beginning.
From pixels to motor movements
John starts by providing an image, usually no more than 100 pixels wide, to a Raspberry Pi. Custom software that he wrote evaluates the darkness of each pixel and selects a pattern of a suitable density to represent it.
The two cords supporting the plotter’s pen are wound around the shafts of two stepper motors, such that the movement of the motors controls the length of the cords: the program next calculates how much each motor must move in order to produce the pattern. The Raspberry Pi passes corresponding instructions to two motor circuits, which transform the signals to a higher voltage and pass them to the stepper motors. These turn by very precise amounts, winding or unwinding the cords and, very slowly, dragging the pen across the paper.
The earlier drawings that John made used a repeatable method to render image files as lines on paper. That is, if the machine drew the same image a number of times, each copy would be identical. More recently, though, he has been using a method that yields random movements of the pen:
The pen point is guided around the image, but moves to each new point entirely at random. Up close this looks like a chaotic squiggle, but from a distance of a couple of meters, the human eye (and brain) make order from the chaos and view an infinite number of shades and a smoother, less mechanical image.
This method means that no matter how many times the polargraph repeats the same image, each copy will be unique.
A gallery of work
Inky Lines’ website and its Instagram feed offer a collection of wonderful pieces John has drawn with his polargraph, and he discusses the different techniques and types of image that he is exploring.
They range from holiday photographs, processed to extract particular features and rendered in silhouette, to portraits, made with a single continuous line that can be several hundred metres long, to generative images spirograph images like those pictured above, created by an algorithm rather than rendered from a source image.
Michael Portera‘s trading card scanner uses LEGO, servo motors, and a Raspberry Pi and Camera Module to scan Magic: The Gathering cards and look up their prices online. This is a neat and easy-to-recreate project that you can adapt for whatever your, or your younger self’s, favourite trading cards are.
For those of you who aren’t this nerdy [Janina is 100% this nerdy – Ed.], Magic: The Gathering (or MTG for short) is a trading card game first launched in 1993. It’s based on a sprawling fantasy multiverse storyline, and is very heavy on mechanics — the current comprehensive rules fill 228 pages! You can imagine it as being a bit like Dungeons and Dragons, with less role-playing and more of a chess vibe. Unlike in chess, however, you can beat your MTG opponent in one turn with just the right combination of cards. If that’s your style of play, that is.
Scanning trading cards
So far, there are around 20000 official MTG cards, and, as with other types of trading cards, some of them are worth a lot of money.
Michael is one of the many people who were keen MTG players in their youth. Here’s how he came up with his project idea:
I was really into trading cards as a kid. I recently came across a lot of Magic: The Gathering cards in a box and thought to myself — I wonder how many cards I have and how much they’re worth?! Logging and looking these up manually would take a while, so I decided to see if I could automate some of the process. Somehow, the process led to building a platform out of Lego and leveraging AWS S3 and Rekognition.
LEGO, servos and camera
To build the housing of the scanner, Michael used LEGO, stating “I’m not good at wood working, and I thought that it might be rough on the cards.” While he doesn’t provide a build plan for the housing, Michael only used bricks from in the LEGO Medium Creative Brick Box he bought for the project. In addition, his tutorial includes a lot of pictures to guide you.
Servo motors spin plastic wheels to move single cards from a stack set into the scanner. Michael positioned a Raspberry Pi Camera Module so that it can take a picture of the title of each card as it is set before the lens. The length of the camera’s ribbon cable gave Michael a little difficulty, so he recommends getting an extension for it if you’re planning to recreate the build.
Optical character recognition and MTG card price API
On the software side, Michael wrote three scripts. One is a Python script to control the servos and take pictures. This, he says, “[records] about 20–25 cards a minute.”
Another script identifies the cards and looks up their prices automatically. Michael tried out OpenCV and Tesseract for optical character recognition (OCR) first, before settling on AWS S3 and Rekognition for storing and processing images, respectively. You’ll need an AWS account to do this — Michael used the free tier, which he says allows him to process 5000 pictures per month.
A sizeable collection
Finally, the data that Rekognition sends back gets processed by another Python script that looks up the identified cards on the TCGplayer API to find their price.
Michael says he’s very satisfied with the accuracy of the project’s OCR. He found out that the 920 Magic: The Gathering cards he scanned are worth about $275 in total. He provides a full write-up plus code over on hackster.io.
And for my next trick…
You might be thinking what I’m thinking: the logical next step for this project is to turn it into a card sorter. Then you could input a list of the card deck you want to put together, and presto! The device picks out the right cards from your collection. Building a Commander deck just became a little easier!
What trading cards would you use this project with, and how would you extend it? Also, what’s your favourite commander? Let me know in the comments!
With the Greenland shark finally caught on video for the very first time, scientists and engineers are discussing the limitations of current marine monitoring technology. One significant advance comes from the CSAIL team at Massachusetts Institute of Technology (MIT): SoFi, the robotic fish.
More info: http://bit.ly/SoFiRobot Paper: http://robert.katzschmann.eu/wp-content/uploads/2018/03/katzschmann2018exploration.pdf
The untethered SoFi robot
Last week, the Computer Science and Artificial Intelligence Laboratory (CSAIL) team at MIT unveiled SoFi, “a soft robotic fish that can independently swim alongside real fish in the ocean.”
Directed by a Super Nintendo controller and acoustic signals, SoFi can dive untethered to a maximum of 18 feet for a total of 40 minutes. A Raspberry Pi receives input from the controller and amplifies the ultrasound signals for SoFi via a HiFiBerry. The controller, Raspberry Pi, and HiFiBerry are sealed within a waterproof, cast-moulded silicone membrane filled with non-conductive mineral oil, allowing for underwater equalisation.
The ultrasound signals, received by a modem within SoFi’s head, control everything from direction, tail oscillation, pitch, and depth to the onboard camera.
As explained on MIT’s news blog, “to make the robot swim, the motor pumps water into two balloon-like chambers in the fish’s tail that operate like a set of pistons in an engine. As one chamber expands, it bends and flexes to one side; when the actuators push water to the other channel, that one bends and flexes in the other direction.”
While we’ve seen many autonomous underwater vehicles (AUVs) using onboard Raspberry Pis, SoFi’s ability to roam untethered with a wireless waterproof controller is an exciting achievement.
“To our knowledge, this is the first robotic fish that can swim untethered in three dimensions for extended periods of time. We are excited about the possibility of being able to use a system like this to get closer to marine life than humans can get on their own.” – CSAIL PhD candidate Robert Katzschmann
As the MIT news post notes, SoFi’s simple, lightweight setup of a single camera, a motor, and a smartphone lithium polymer battery set it apart it from existing bulky AUVs that require large motors or support from boats.
For more in-depth information on SoFi and the onboard tech that controls it, find the CSAIL team’s paper here.
This is part two of a series on the factors that an organization needs to consider when opening a data center and the challenges that must be met in the process.
In Part 1 of this series, we looked at the different types of data centers, the importance of location in planning a data center, data center certification, and the single most expensive factor in running a data center, power.
In Part 2, we continue to look at factors that need to considered both by those interested in a dedicated data center and those seeking to colocate in an existing center.
In part 1, we began our discussion of the power requirements of data centers.
As we discussed, redundancy and failover is a chief requirement for data center power. A redundantly designed power supply system is also a necessity for maintenance, as it enables repairs to be performed on one network, for example, without having to turn off servers, databases, or electrical equipment.
The common critical components of a data center’s power flow are:
Uninterruptible Power Supplies (UPS)
Utility Supply is the power that comes from one or more utility grids. While most of us consider the grid to be our primary power supply (hats off to those of you who manage to live off the grid), politics, economics, and distribution make utility supply power susceptible to outages, which is why data centers must have autonomous power available to maintain availability.
Generators are used to supply power when the utility supply is unavailable. They convert mechanical energy, usually from motors, to electrical energy.
Transfer Switches are used to transfer electric load from one source or electrical device to another, such as from one utility line to another, from a generator to a utility, or between generators. The transfer could be manually activated or automatic to ensure continuous electrical power.
Distribution Panels get the power where it needs to go, taking a power feed and dividing it into separate circuits to supply multiple loads.
A UPS, as we touched on earlier, ensures that continuous power is available even when the main power source isn’t. It often consists of batteries that can come online almost instantaneously when the current power ceases. The power from a UPS does not have to last a long time as it is considered an emergency measure until the main power source can be restored. Another function of the UPS is to filter and stabilize the power from the main power supply.
Data center UPSs
PDU stands for the Power Distribution Unit and is the device that distributes power to the individual pieces of equipment.
After power, the networking connections to the data center are of prime importance. Can the data center obtain and maintain high-speed networking connections to the building? With networking, as with all aspects of a data center, availability is a primary consideration. Data center designers think of all possible ways service can be interrupted or lost, even briefly. Details such as the vulnerabilities in the route the network connections make from the core network (the backhaul) to the center, and where network connections enter and exit a building, must be taken into consideration in network and data center design.
Routers and switches are used to transport traffic between the servers in the data center and the core network. Just as with power, network redundancy is a prime factor in maintaining availability of data center services. Two or more upstream service providers are required to ensure that availability.
How fast a customer can transfer data to a data center is affected by: 1) the speed of the connections the data center has with the outside world, 2) the quality of the connections between the customer and the data center, and 3) the distance of the route from customer to the data center. The longer the length of the route and the greater the number of packets that must be transferred, the more significant a factor will be played by latency in the data transfer. Latency is the delay before a transfer of data begins following an instruction for its transfer. Generally latency, not speed, will be the most significant factor in transferring data to and from a data center. Packets transferred using the TCP/IP protocol suite, which is the conceptual model and set of communications protocols used on the internet and similar computer networks, must be acknowledged when received (ACK’d) and requires a communications roundtrip for each packet. If the data is in larger packets, the number of ACKs required is reduced, so latency will be a smaller factor in the overall network communications speed.
Those interested in testing the overall speed and latency of their connection to Backblaze’s data centers can use the Check Your Bandwidth tool on our website.
Data center telecommunications equipment
Data center under floor cable runs
Computer, networking, and power generation equipment generates heat, and there are a number of solutions employed to rid a data center of that heat. The location and climate of the data center is of great importance to the data center designer because the climatic conditions dictate to a large degree what cooling technologies should be deployed that in turn affect the power used and the cost of using that power. The power required and cost needed to manage a data center in a warm, humid climate will vary greatly from managing one in a cool, dry climate. Innovation is strong in this area and many new approaches to efficient and cost-effective cooling are used in the latest data centers.
Switch’s uninterruptible, multi-system, HVAC Data Center Cooling Units
There are three primary ways data center cooling can be achieved:
Room Cooling cools the entire operating area of the data center. This method can be suitable for small data centers, but becomes more difficult and inefficient as IT equipment density and center size increase.
Row Cooling concentrates on cooling a data center on a row by row basis. In its simplest form, hot aisle/cold aisle data center design involves lining up server racks in alternating rows with cold air intakes facing one way and hot air exhausts facing the other. The rows composed of rack fronts are called cold aisles. Typically, cold aisles face air conditioner output ducts. The rows the heated exhausts pour into are called hot aisles. Typically, hot aisles face air conditioner return ducts.
Rack Cooling tackles cooling on a rack by rack basis. Air-conditioning units are dedicated to specific racks. This approach allows for maximum densities to be deployed per rack. This works best in data centers with fully loaded racks, otherwise there would be too much cooling capacity, and the air-conditioning losses alone could exceed the total IT load.
Data Centers are high-security facilities as they house business, government, and other data that contains personal, financial, and other secure information about businesses and individuals.
This list contains the physical-security considerations when opening or co-locating in a data center:
Layered Security Zones. Systems and processes are deployed to allow only authorized personnel in certain areas of the data center. Examples include keycard access, alarm systems, mantraps, secure doors, and staffed checkpoints.
Physical Barriers. Physical barriers, fencing and reinforced walls are used to protect facilities. In a colocation facility, one customers’ racks and servers are often inaccessible to other customers colocating in the same data center.
Backblaze racks secured in the data center
Monitoring Systems. Advanced surveillance technology monitors and records activity on approaching driveways, building entrances, exits, loading areas, and equipment areas. These systems also can be used to monitor and detect fire and water emergencies, providing early detection and notification before significant damage results.
Top-tier providers evaluate their data center security and facilities on an ongoing basis. Technology becomes outdated quickly, so providers must stay-on-top of new approaches and technologies in order to protect valuable IT assets.
To pass into high security areas of a data center requires passing through a security checkpoint where credentials are verified.
The gauntlet of cameras and steel bars one must pass before entering this data center
Facilities and Services
Data center colocation providers often differentiate themselves by offering value-added services. In addition to the required space, power, cooling, connectivity and security capabilities, the best solutions provide several on-site amenities. These accommodations include offices and workstations, conference rooms, and access to phones, copy machines, and office equipment.
Additional features may consist of kitchen facilities, break rooms and relaxation lounges, storage facilities for client equipment, and secure loading docks and freight elevators.
Would you Like to Know More about The Challenges of Opening and Running a Data Center?
That’s it for part 2 of this series. If readers are interested, we could write a post about some of the new technologies and trends affecting data center design and use. Please let us know in the comments.
Don’t miss future posts on data centers and other topics, including hard drive stats, cloud storage, and tips and tricks for backing up to the cloud. Use the Join button above to receive notification of future posts on our blog.
Learn how to apply the thinking and programming skills you’ve learnt in Scratch to text-based programming languages like Python.
Take the plunge into text-based programming
The idea for this course arose from our conversations with educators who had set up a Code Club in their schools. Most people start a club by teaching Scratch, a block-based programming language, because it allows learners to drag and drop blocks of pre-written code into a window to create a program. The blocks automatically snap together, making it easy to build fun and educational projects that don’t require much troubleshooting. You can do almost anything a beginner could wish for with Scratch, even physical computing to control LEDs, buzzers, buttons, motors, and more!
However, on our face-to-face training programme Picademy, educators told us that they were finding it hard to engage children who had outgrown Scratch and needed a new challenge. It was easy for me to imagine: a young learner, who once felt confident about programming using Scratch, is now confused by the alien, seemingly awkward interface of Python. What used to take them minutes in Scratch now takes them hours to code, and they start to lose interest — not a good result, I’m sure you’ll agree. I wanted to help educators to navigate this period in their learners’ development, and so I’ve written a course that shows you how to take the programming and thinking skills you and your learners have developed in Scratch, and apply them to Python.
Who is the course for?
Educators from all backgrounds who are working with secondary school-aged learners. It will also be interesting to anyone who has spent time working with Scratch and wants to understand how programming concepts translate between different languages.
“It was great fun, and I thought that the ideas and resources would be great to use with Year 7 classes.” Sue Grey, Classroom Teacher
What is covered?
After showing you the similarities and differences of Scratch and Python, and how the skills learned using one can be applied to the other, we will look at turning more complex Scratch scripts into Python programs. Through creating a Mad Libs game and developing a username generator, you will see how programs can be simplified in a text-based language. We will give you our top tips for debugging Python code, and you’ll have the chance to share your ideas for introducing more complex programs to your students.
After that, we will look at different data types in Python and write a script to calculate how old you are in dog years. Finally, you’ll dive deeper into the possibilities of Python by installing and using external Python libraries to perform some amazing tasks.
By the end of the course, you’ll be able to:
Transfer programming and thinking skills from Scratch to Python
Use fundamental Python programming skills
Identify errors in your Python code based on error messages, and debug your scripts
Produce tools to support students’ transition from block-based to text-based programming
Understand the power of text-based programming and what you can create with it
The first introduction to my latest barbot – this time made inside a grandfather clock. There is another video where I explain a bit about how it works, and am happy to give more explanations. https://youtu.be/hdxV_KKH5MA This can make cocktails with up to 4 spirits, and 4 mixers, and is controlled by voice, keyboard input, or a gui, depending which is easiest.
Robert Prest’s Barbot 4 is a beverage dispenser loaded into an old Grandfather clock. There’s space in the back for your favourite spirits and mixers, and a Raspberry Pi controls servo motors that release the required measures of your favourite cocktail ingredients, according to preset recipes.
The clock can hold four mixers and four spirits, and a human supervisor records these using Drinkydoodad, a friendly touchscreen interface. With information about its available ingredients and a library of recipes, Barbot 4 can create your chosen drink. Patrons control the system either with voice commands or with the touchscreen UI.
Robert has experimented with various components as this project has progressed. He has switched out peristaltic pumps in order to increase the flow of liquid, and adjusted the motors so that they can handle carbonated beverages. In the video, he highlights other quirks he hopes to address, like the fact that drinks tend to splash during pouring.
As well as a Raspberry Pi, the build uses Arduinos. These control the light show, which can be adjusted according to your party-time lighting preferences.
An explanation of the build accompanies Robert’s second video. We’re hoping he’ll also release more details of Barbot 3, his suitcase-sized, portable Barbot, and of Doom Shot Bot, a bottle topper that pours a shot every time you die in the game DoomZ.
Barbot 4 isn’t the first cocktail-dispensing Raspberry Pi bartender we’ve seen, though we have to admit that fitting it into a grandfather clock definitely makes it one of the quirkiest.
If you’ve built a similar project using a Raspberry Pi, we’d love to see it. Share your project in the comments, or tell us what drinks you’d ask Barbot to mix if you had your own at home.
Standard clocks with easily recognisable numbers are so last season. Who wants to save valuable seconds simply telling the time, when a series of LEDs and numerical notation can turn every time query into an adventure in mathematics?
In this video I’ll be showing how I built a binary clock using a Raspberry Pi, NeoPixels and a few lines of Python. I also take a stab at explaining how the binary number system works so that we can decipher what said clock is trying to tell us.
How to read binary
I’ll be honest: I have to think pretty hard to read binary. It stretches my brain quite vigorously. But I am a fan of flashy lights and pretty builds, so YouTube and Instagram rising star Mattias Jähnke, aka engineerish, had my full attention from the off.
“If you have a problem with your friends being able to tell the time way too easily while in your house, this is your answer.”
Mattias offers a beginners’ guide in to binary in his video and then explains how his clock displays values in binary, before moving on to the actual clock build process. So make some tea, pull up a chair, and jump right in.
To build the clock, Mattias used a Raspberry Pi and NeoPixel strips, fitted snugly within a simple 3D-printed case. With a few lines of Python, he coded his clock to display the current time using the binary system, with columns for seconds, minutes, and hours.
418 Likes, 14 Comments – Mattias (@engineerish) on Instagram: “The real kicker with a binary clock is that by the time you’ve deciphered what time it is – you’re…”
The Python code isn’t currently available on Mattias’s GitHub account, but if you’re keen to see how he did it, and you ask politely, and he’s not too busy, you never know.
Make your own
In the meantime, while we batter our eyelashes in the general direction of Stockholm and hope for a response, I challenge any one of you to code a binary display project for the Raspberry Pi. It doesn’t have to be a clock. And it doesn’t have to use NeoPixels. Maybe it could use an LED matrix such as the SenseHat, or a series of independently controlled LEDs on a breadboard. Maybe there’s something to be done with servo motors that flip discs with different-coloured sides to display a binary number.
Whatever you decide to build, the standard reward applies: ten imaginary house points (of absolutely no practical use, but immense emotional value) and a great sense of achievement to all who give it a go.
Allow your robots to join in the fun this Christmas with a round of Channel 4’s Countdown. https://www.rosietheredrobot.com/2017/12/tea-minus-30.html
Rosie the Red Robot
First, a little bit of backstory. Challenged by his eldest daughter to build a robot, technology-loving Alan got to work building Rosie.
I became (unusually) determined. I wanted to show her what can be done… and the how can be learnt later. After all, there is nothing more exciting and encouraging than seeing technology come alive. Move. Groove. Quite literally.
Originally, Rosie had a Raspberry Pi 3 brain controlling ultrasonic sensors and motors via Python. From there, she has evolved into something much grander, and Alan has documented her upgrades on the Rosie the Red Robot blog. Using GPS trackers and a Raspberry Pi camera module, she became Rosie Patrol, a rolling, walking, interactive bot; then, with further upgrades, the Tea Minus 30 project came to be. Which brings us back to Countdown.
T(ea) minus 30
In case it hasn’t been a big part of your life up until now, Countdown is one of the longest running televisions shows in history, and occupies a special place in British culture. Contestants take turns to fill a board with nine randomly selected vowels and consonants, before battling the Countdown clock to find the longest word they can in the space of 30 seconds.
I’ve had quite a few requests to show just the Countdown clock for use in school activities/own games etc., so here it is! Enjoy! It’s a brand new version too, using the 2010 Office package.
There’s a numbers round involving arithmetic, too – but for now, we’re going to focus on letters and words, because that’s where Rosie’s skills shine.
Using an online resource, Alan created a dataset of the ten thousand most common English words.
Many words, listed in order of common-ness. Alan wrote a Python script to order them alphabetically and by length
Next, Alan wrote a Python script to select nine letters at random, then search the word list to find all the words that could be spelled using only these letters. He used the randint function to select letters from a pre-loaded alphabet, and introduced a requirement to include at least two vowels among the nine letters.
Words that match the available letters are displayed on the screen.
Putting it all together
With the basic game-play working, it was time to bring the project to life. For this, Alan used Rosie’s camera module, along with optical character recognition (OCR) and text-to-speech capabilities.
Alan writes, “Here’s a very amateurish drawing to brainstorm our idea. Let’s call it a design as it makes it sound like we know what we’re doing.”
Alan’s script has Rosie take a photo of the TV screen during the Countdown letters round, then perform OCR using the Google Cloud Vision API to detect the nine letters contestants have to work with. Next, Rosie runs Alan’s code to check the letters against the ten-thousand-word dataset, converts text to speech with Python gTTS, and finally speaks her highest-scoring word via omxplayer.
You can follow the adventures of Rosie the Red Robot on her blog, or follow her on Twitter. And if you’d like to build your own Rosie, Alan has provided code and tutorials for his projects too. Thanks, Alan!
I need your help. This is a call out for those between 11- and 16-years-old in the UK and Republic of Ireland. Something has gone very, very wrong and only you can save us. I’ve collected together as much information for you as I can. You’ll find it at http://www.raspberrypi.org/pioneers.
In August we intercepted an emergency communication from a lonesome survivor. She seemed to be in quite a bit of trouble, and asked all you young people aged 11 to 16 to come up with something to help tackle the oncoming crisis, using whatever technology you had to hand. You had ten weeks to work in teams of two to five with an adult mentor to fulfil your mission.
We received your world-saving ideas, and our savvy survivor pulled together a ragtag bunch of apocalyptic experts to help us judge which ones would be the winning entries.
Dr Shini Somara is an advocate for STEM education and a mechanical engineer. She was host of The Health Show and has appeared in documentaries for the BBC, PBS Digital, and Sky. You can check out her work hosting Crash Course Physics on YouTube.
Prof Lewis Dartnell is an astrobiologist and author of the book The Knowledge: How to Rebuild Our World From Scratch.
Emma Stephenson has a background in aeronautical engineering and currently works in the Shell Foundation’s Access to Energy and Sustainable Mobility portfolio.
151 Likes, 3 Comments – Shini Somara (@drshinisomara) on Instagram: “Currently sifting through the entries with the other judges of #makeyourideas with…”
Our survivor is currently putting your entries to good use repairing, rebuilding, and defending her base. Our judges chose the following projects as outstanding examples of world-saving digital making.
This is our entry to the pioneers ‘Only you can save us’ competition. Our team name is Computatrum. Hope you enjoy!
Are you facing an unknown enemy whose only weakness is Nerf bullets? Then this is the robot for you! We loved the especially apocalyptic feel of the Computatron’s cleverly hacked and repurposed elements. The team even used an old floppy disc mechanism to help fire their bullets!
Thousands of lines of code… Many sheets of acrylic… A camera, touchscreen and fingerprint scanner… This is our entry into the Raspberry Pi Pioneers2017 ‘Only YOU can Save Us’ theme. When zombies or other survivors break into your base, you want a secure way of storing your crackers.
The Robot Apocalypse Committee is back, and this time they’ve brought cheese! The crew designed a cheese- and cracker-dispensing machine complete with face and fingerprint recognition to ensure those rations last until the next supply drop.
Hi! We are PiChasers and we entered the Raspberry Pi Pionners challenge last time when the theme was “Make it Outdoors!” but now we’ve been faced with another theme “Apocolypse”. We spent a while thinking of an original thing that would help in an apocolypse and decided upon a ‘text-only phone’ which uses local radio communication rather than cellular.
This text-based communication device encased in a tupperware container could be a lifesaver in a crisis! And luckily, the Pi Chasers produced an excellent video and amazing GitHub repo, ensuring that any and all survivors will be able to build their own in the safety of their base.
Pioneers Entry Team Name: The Three Musketeers Team Participants: James, Zach and Tom
We all know that zombies are terrible at geometry, and the Three Musketeers used this fact to their advantage when building their zombie security system. We were impressed to see the team working together to overcome the roadblocks they faced along the way.
We appreciate what you’re trying to do: Zombie Trolls
Playing piggy in the middle with zombies sure is a unique way of saving humankind from total extinction! We loved this project idea, and although the Zombie Trolls had a little trouble with their motors, we’re sure with a little more tinkering this zombie-fooling contraption could save us all.
Our judges also wanted to give a special commendation to the following teams for their equally awesome apocalypse-averting ideas:
PiRates, for their multifaceted zombie-proofing defence system and the high production value of their video
Byte them Pis, for their beautiful zombie-detecting doormat
Unatecxon, for their impressive bunker security system
Team Crompton, for their pressure-activated door system
Looking for the perfect Christmas gift for a beloved maker in your life? Maybe you’d like to give a relative or friend a taste of the world of coding and Raspberry Pi? Whatever you’re looking for, the Raspberry Pi Christmas shopping list will point you in the right direction.
For those getting started
Thinking about introducing someone special to the wonders of Raspberry Pi during the holidays? Although you can set up your Pi with peripherals from around your home, such as a mobile phone charger, your PC’s keyboard, and the old mouse dwelling in an office drawer, a starter kit is a nice all-in-one package for the budding coder.
If you’re looking for something for a confident digital maker, you can’t go wrong with adding to their arsenal of electric and electronic bits and bobs that are no doubt cluttering drawers and boxes throughout their house.
Components such as servomotors, displays, and sensors are staples of the maker world. And when it comes to jumper wires, buttons, and LEDs, one can never have enough.
You could also consider getting your person a soldering iron, some helpings hands, or small tools such as a Dremel or screwdriver set.
And to make their life a little less messy, pop it all inside a Really Useful Box…because they’re really useful.
For kit makers
While some people like to dive into making head-first and to build whatever comes to mind, others enjoy working with kits.
The Naturebytes kit allows you to record the animal visitors of your garden with the help of a camera and a motion sensor. Footage of your local badgers, birds, deer, and more will be saved to an SD card, or tweeted or emailed to you if it’s in range of WiFi.
Coretec’s Tiny 4WD is a kit for assembling a Pi Zero–powered remote-controlled robot at home. Not only is the robot adorable, building it also a great introduction to motors and wireless control.
Looking for something small to keep your loved ones occupied on Christmas morning? Or do you have to buy a Secret Santa gift for the office tech? Here are some wonderful stocking fillers to fill your boots with this season.
The Pi Hut 3D Xmas Tree: available as both a pre-soldered and a DIY version, this gadget will work with any 40-pin Raspberry Pi and allows you to create your own mini light show.
Google AIY Voice kit: build your own home assistant using a Raspberry Pi, the MagPi Essentials guide, and this brand-new kit. “Google, play Mariah Carey again…”
LEGO Idea’s bought out this amazing ‘Women of NASA’ set, and I thought it would be fun to build, play and learn from these inspiring women! First up, let’s discover a little more about Sally Ride and Mae Jemison, two AWESOME ASTRONAUTS!
Treat the kids, and big kids, in your life to the newest LEGO Ideas set, the Women of NASA — starring Nancy Grace Roman, Margaret Hamilton, Sally Ride, and Mae Jemison!
Explore the world of wearables with Pimoroni’s sewable, hackable, wearable, adorable Bearables kits.
With so many amazing kits, HATs, and books available from members of the Raspberry Pi community, it’s hard to only pick a few. Have you found something splendid for the maker in your life? Maybe you’ve created your own kit that uses the Raspberry Pi? Share your favourites with us in the comments below or via our social media accounts.
We created Pip so that anyone can tinker with technology. From beginners to those who know more — Pip makes it easy, simple, and fun!
Pip’s smart design may well remind you of a certain handheld gaming console released earlier this year. With its central screen and detachable side controllers, Pip has a size and shape ideal for gaming.
Those who have used a Raspberry Pi with the Raspbian OS might be familiar with Minecraft Pi, a variant of the popular Minecraft game created specifically for Pi users to play and hack for free. Users of Pip will be able to access Minecraft Pi from the portable device and take their block-shaped creations with them wherever they go.
And if that’s not enough, Pip’s Pi brain allows coders to create their own games using Scratch, in addition to giving access a growing library of games in Curious Chip’s online arcade.
Pip’s GPIO pins are easily accessible, so that you can expand upon your digital making skills with physical computing projects. Grab your Pip and a handful of jumper leads, and you will be able to connect and control components such as lights, buttons, servomotors, and more!
Maker Pack and add-ons
Backers can also pledge their funds for additional hardware, such as the Maker Pack, an integrated camera, or a Pip Breadboard Kit.
The breadboard and the optional PipHAT are also compatible with any Raspberry Pi 2 and 3. Nice!
Curiosity from Curious Chip
Users of Pip can program their device via Curiosity, a tool designed specifically for this handheld device.
Back the project
If you’d like to back Curious Chip and bag your own Pip, you can check out their Kickstarter page here. And if you watch their promo video closely, you may see a familiar face from the Raspberry Pi community.
Are you planning on starting your own Raspberry Pi-inspired crowd-funded campaign? Then be sure to tag us on social media. We love to see what the community is creating for our little green (or sometimes blue) computer.
Day 172 of #3dprint365. #3dprinted Raspberry PI Controlled Maze Thingie Part 3 #3dprint #3dprinter #thingiverse #raspberrypi #pisupply
All non-electronic parts of this build are 3D printed. The marble maze sits atop a motorised structure which moves along two axes thanks to servo motors. Tom controls the movement using gestures which are picked up by the Flick Zero, a Pi Zero–sized 3D-tracking board that can detect movement up to 15cm away.
Find the code for the maze, which takes advantage of the Flick library, on Tom’s GitHub account.
Make your own games
Our free resources are a treasure trove of fun home-brew games that you can build with your friends and family.
If you like physical games such as Tom’s gesture-controlled maze, you should definitely check out our Python quick reaction game! In it, players are pitted against each other to react as quickly as possible to a randomly lighting up LED.
You can also play solo with our Lights out game, where it’s you against four erratic lights eager to remain lit.
For games you can build on your computer with no need for any extra tech, Scratch games such as our button-smashing Olympic weightlifter and Hurdler projects are perfect — you can play them just using a keyboard and browser!
And because I just found this while searching for image content for today’s blog, here is a photo of Eben’s and Liz’s cat Mooncake with a Raspberry Pi on her head. Enjoy!
Halloween: that glorious time of year when you’re officially allowed to make your friends jump out of their skin with your pranks. For those among us who enjoy dressing up, Halloween is also the occasion to go all out with costumes. And so, dear reader, we present to you: a steampunk tentacle hat, created by Derek Woodroffe.
Derek is an engineer who loves all things electronics. He’s part of Extreme Kits, and he runs the website Extreme Electronics. Raspberry Pi Zero-controlled Tesla coils are Derek’s speciality — he’s even been on one of the Royal Institution’s Christmas Lectures with them! Skip ahead to 15:06 in this video to see Derek in action:
The first Lecture from Professor Saiful Islam’s 2016 series of CHRISTMAS LECTURES, ‘Supercharged: Fuelling the future’. Watch all three Lectures here: http://richannel.org/christmas-lectures 2016 marked the 80th anniversary since the BBC first broadcast the Christmas Lectures on TV. To celebrate, chemist Professor Saiful Islam explores a subject that the lectures’ founder – Michael Faraday – addressed in the very first Christmas Lectures – energy.
Wearables are electronically augmented items you can wear. They might take the form of spy eyeglasses, clothes with integrated sensors, or, in this case, headgear adorned with mechanised tentacles.
Why did Derek make this? We’re not entirely sure, but we suspect he’s a fan of the Cthulu mythos. In any case, we were a little astounded by his project. This is how we reacted when Derek tweeted us about it:
@ExtElec @extkits This is beyond incredible and completely unexpected.
In fact, we had to recover from a fit of laughter before we actually managed to type this answer.
Making a steampunk tentacle hat
Derek made the ‘skeleton’ of each tentacle out of a net curtain spring, acrylic rings, and four lengths of fishing line. Two servomotors connect to two ends of fishing line each, and pull them to move the tentacle.
Then he covered the tentacles with nylon stockings and liquid latex, glued suckers cut out of MDF onto them, and mounted them on an acrylic base. The eight motors connect to a Raspberry Pi via an I2C 8-port PWM controller board.
The Pi makes the servos pull the tentacles so that they move in sine waves in both the x and y directions, seemingly of their own accord. Derek cut open the top of a hat to insert the mounted tentacles, and he used more liquid latex to give the whole thing a slimy-looking finish.
Iä! Iä! Cthulhu fhtagn!
You can read more about Derek’s steampunk tentacle hat here. He will be at the Beeston Raspberry Jam in November to show off his build, so if you’re in the Nottingham area, why not drop by?
Wearables for Halloween
This build is already pretty creepy, but just imagine it with a sensor- or camera-powered upgrade that makes the tentacles reach for people nearby. You’d have nightmare fodder for weeks.
With the help of the Raspberry Pi, any Halloween costume can be taken to the next level. How could Pi technology help you to win that coveted ‘Scariest costume’ prize this year? Tell us your ideas in the comments, and be sure to share pictures of you in your get-up with us on Twitter, Facebook, or Instagram.
Robot-builder extraordinaire Clément Didier is ushering in the era of our cybernetic overlords. Future generations will remember him as the creator of robots constructed from cardboard and conductive paint which are so easy to replicate that a robot could do it. Welcome to the singularity.
This cool robot was made with the #PiCap, conductive paint and @Raspberry_Pi by @clementdidier. Full tutorial: https://t.co/AcQVTS4vr2 https://t.co/D04U5UGR0P
To assemble the robot, Clément made use of a Pi Cap board, a motor driver, and most importantly, a tube of Bare Conductive Electric Paint. He painted the control interface onto the cardboard surface of the robot, allowing a human, replicant, or superior robot to direct its movements simply by touching the paint.
The Raspberry Pi 3, the motor control board, and the painted input buttons interface via the GPIO breakout pins on the Pi Cap. Crocodile clips connect the Pi Cap to the cardboard-and-paint control surface, while jumper wires connect it to the motor control board.
Sing with me: ‘The Raspberry Pi’s connected to the Pi Cap, and the Pi Cap’s connected to the inputs, and…’
Two battery packs provide power to the Raspberry Pi, and to the four independently driven motors. Software, written in Python, allows the robot to respond to inputs from the conductive paint. The motors drive wheels attached to a plastic chassis, moving and turning the robot at the touch of a square of black paint.
Clément used masking tape and a paintbrush to create the control buttons. For a human, this is obviously a fiddly process which relies on the blocking properties of the masking tape and a steady hand. For a robot, however, the process would be a simple, freehand one, resulting in neatly painted circuits on every single one of countless robotic minions. Cybernetic domination is at (metallic) hand.
One fiddly job for a human, one easy task for robotkind
The instructions and code for Clément’s build can be found here.
David Pride, known to many of you as an active member of our maker community, has done it again! His FRED-209 build combines a Nerf gun, 3D printing, a Raspberry Pi Zero, and robotics to make one neat remotely controlled Nerf tank.
David says he worked on FRED-209 over the summer in order to have some fun with Nerf guns, which weren’t around when he was a kid. He purchased an Elite Stryfe model at a car boot sale, and took it apart to see what made it tick. Then he set about figuring out how to power it with motors and a servo.
To control the motors, David used a ZeroBorg add-on board for the Pi Zero, and he set up a PlayStation 3 controller to pilot his tank. These components were also part of a robot that David entered into the Pi Wars competition, so he had already written code for them.
3D printing for FRED-209
During prototyping for his Nerf tank, which David named after ED-209 from RoboCop, he used lots of eBay loot and several 3D-printed parts. He used the free OpenSCAD software package to design the parts he wanted to print. If you’re a novice at 3D printing, you might find the printing advice he shares in the write-up on his blog very useful.
David found the 3D printing of the 24–cm-long lid of FRED-209 tricky
On eBay, David found some cool-looking chunky wheels, but these turned out to be too heavy for the motors. In the end, he decided to use a Rover 5 chassis, which changed the look of FRED-209 from ‘monster truck’ to ‘tank’.
Next step: teach it to use stairs
The final result looks awesome, and David’s video demonstrates that it shoots very accurately as well. A make like this might be a great defensive project for our new apocalypse-themed Pioneers challenge!
Taking FRED-209 further
David will be uploading code and STL files for FRED-209 soon, so keep an eye on his blog or Twitter for updates. He’s also bringing the Nerf tank to the Cotswold Raspberry Jam this weekend. If you’re attending the event, make sure you catch him and try FRED-209 out yourself.
Never one to rest on his laurels, David is already working on taking his build to the next level. He wants to include a web interface controller and a camera, and is working on implementing OpenCV to give the Nerf tank the ability to autonomously detect targets.
Pi Wars 2018
I have a feeling we might get to see an advanced version of David’s project at next year’s Pi Wars!
The 2018 Pi Wars have just been announced. They will take place on 21-22 April at the Cambridge Computer Laboratory, and you have until 3 October to apply to enter the competition. What are you waiting for? Get making! And as always, do share your robot builds with us via social media.
Why stick to conventional laser cutters or CNC machines for creating images on wood, when you can build a device to do the job that is a beautiful piece of art in itself? Mechanical and Computer Science student and Imgur user Tucker Shannon has created a wonderful-looking CNC Wood Burner using a Raspberry Pi and stepper motors. His project has a great vinyl-turntable-like design.
Tucker’s somewhat hypnotic build burns images into wood using a Raspberry Pi and stepper motors GIF c/o Tucker Shannon
A CNC Wood Burner?
Sure! Why not? Tucker had already put the knowledge he acquired while studying at Oregon State University to good use by catching a bike thief in action with the help of a Raspberry Pi. Thus it’s obvious he has the skills he needed to incorporate our little computer into a project. Moreover, his Skittles portrait of Bill Nye is evidence of his artistic flare, so it’s not surprising that he wanted to make something a little different, and pretty, using code.
“Bill Nye, the Skittles Guy” Image c/o Tucker Shannon
With an idea in mind and sketches drawn, Tucker first considered using an old record player as the base of his build. Having a rotating deck and arm already in place would have made building his project easier. However, he reports on Imgur:
I thought about that! I couldn’t find any at local thrift shops though. Apparently, they’ve become pretty popular…
Taking into consideration the lumps and bumps of the wood he would be using as a ‘canvas’, Tucker decided to incorporate a pivot to allow the arm to move smoothly over the rough surface.
The code for the make is currently in ‘spaghetti form’, though Tucker is set to release it, as well as full instructions for the build, in the near future.
Tucker laser-cut the pieces for the wood burner’s box and gear out of birch and pine wood. As the motors require 12v power, the standard Raspberry Pi supply wasn’t going to be enough. Therefore, Tucker scavenged for old computer parts , and ended up rescuing a PSU (power supply unit). He then fitted the PSU and the Raspberry Pi within the box.
The cannibalised PSU, stepper motor controller, and Raspberry Pi fit nicely into Tucker’s handmade pine box. Image c/o Tucker Shannon
Next, he got to work building runners for the stepper motor controlling the position of the ‘pen thing’ that would scorch the image into the wood.
Initial tests on paper help to align the pen Image c/o Tucker Shannon
After a few test runs using paper, the CNC Wood Burner was good to go!
Tucker has used his CNC Wood Burner to create some wonderful pieces of art. The few examples he’s shared on Imgur have impressed us with their precision. We’re looking forward to seeing what else he is going to make with it!
The build burns wonderfully clean-lined images into wood Image c/o Tucker Shannon
Image replication using Raspberry Pis and stepper motors isn’t a new thing – though doing it using a wood-burning device may be! We’ve seen some great builds in which makers set up motors and a marker pen to create massive works of art. Are you one of those makers? Or have you been planning a build similar to Tucker’s project, possibly with a new twist?
Share your project with us below, whether it is complete or still merely sketches in a notebook. We’d love to see what you’re getting up to!
At this year’s TechCrunch Disrupt NY hackathon, one team presented BackMap, a haptic feedback system which helps visually impaired people to navigate cities and venues. It is assisted by a Raspberry Pi and integrated into a backpack.
Good vibrations with BackMap
The team, including Shashank Sharma, wrote an iOS phone app in Swift, Apple’s open-source programming language. To convert between addresses and geolocations, they used the Esri APIs offered by PubNub. So far, so standard. However, they then configured their BackMap setup so that the user can input their destination via the app, and then follow the route without having to look at a screen or listen to directions. Instead, vibrating motors have been integrated into the straps of a backpack and hooked up to a Raspberry Pi. Whenever the user needs to turn left or right, the Pi makes the respective motor vibrate.
Disrupt NY 2017 Hackathon presentations filmed live on May 15th, 2017. Preceding the Disrupt Conference is Hackathon weekend on May 13-14, where developers and engineers descend from all over the world to take part in a 24-hour hacking endurance test.
BackMap can also be adapted for indoor navigation by receiving signals from beacons. This could be used to direct users to toilet facilities or exhibition booths at conferences. The team hopes to upgrade the BackMap device to use a wristband format in the future.
Here at Pi Towers, we are always glad to see Pi builds for people with disabilities: we’ve seen Sanskriti and Aman’s Braille teacher Mudra, the audio e-reader Valdema by Finnish non-profit Kolibre, and Myrijam and Paul’s award-winning, eye-movement-controlled wheelchair, to name but a few.
Our mission is to bring the power of coding and digital making to everyone, and we are lucky to be part of a diverse community of makers and educators who have often worked proactively to make events and resources accessible to as many people as possible. There is, for example, the autism- and Tourette’s syndrome-friendly South London Raspberry Jam, organised by Femi Owolade-Coombes and his mum Grace. The Raspberry VI website is a portal to all things Pi for visually impaired and blind people. Deaf digital makers may find Jim Roberts’ video tutorials, which are signed in ASL, useful. And anyone can contribute subtitles in any language to our YouTube channel.
If you create or use accessible tutorials, or run a Jam, Code Club, or CoderDojo that is designed to be friendly to people who are neuroatypical or have a disability, let us know how to find your resource or event in the comments!
As I noted at the time, many AWS customers want to collect and process data out in the field, where connectivity is often slow and sometimes either intermittent or unreliable. Greengrass allows them to extend the AWS programming model to small, simple, field-based devices. It builds on AWS IoT and AWS Lambda, and supports access to the ever-increasing variety of services that are available in the AWS Cloud.
Greengrass gives you access to compute, messaging, data caching, and syncing services that run in the field, and that do not depend on constant, high-bandwidth connectivity to an AWS Region. You can write Lambda functions in Python 2.7 and deploy them to your Greengrass devices from the cloud while using device shadows to maintain state. Your devices and peripherals can talk to each other using local messaging that does not pass through the cloud.
Now Generally Available Today we are making Greengrass generally available in the US East (Northern Virginia) and US West (Oregon) Regions. During the preview, AWS customers were able to get hands-on experience with Greengrass and to start building applications and businesses around it. I’ll share a few of these early successes later in this post.
The Greengrass Core code runs on each device. It allows you to deploy and run Lambda applications on the device, supports local MQTT messaging across a secure network, and also ensures that conversations between devices and the cloud are made across secure connections. The Greengrass Core also supports secure, over-the-air software updates, including Lambda functions. It includes a message broker, a Lambda runtime, a Thing Shadows implementation, and a deployment agent. Greengrass Core and (optionally) other devices make up a Greengrass Group. The group includes configuration data, the list of devices and the identity of the Greengrass Core, a list of Lambda functions, and a set of subscriptions that define where the messages should go. All of this information is copied to the Greengrass core devices during the deployment process.
Your Lambda functions can use APIs in three distinct SDKs:
AWS IoT Device SDK – This SDK (available for Node.js, Python, Java, and C++) helps you to connect your hardware devices to AWS IoT. The C++ SDK has a few extra features including access to the Greengrass Discovery Service and support for root CA downloads.
AWS Greengrass Core SDK – This SDK provides APIs that allow local invocation of other Lambda functions, publish messages, and work with thing shadows.
You can run the Greengrass Core on x86 and ARM devices that have version 4.4.11 (or newer) of the Linux kernel, with the OverlayFS and user namespace features enabled. While most deployments of Greengrass will be targeted at specialized, industrial-grade hardware, you can also run the Greengrass Core on a Raspberry Pi or an EC2 instance for development and test purposes.
For this post, I used a Raspberry Pi attached to a BrickPi, connected to my home network via WiFi:
The Raspberry Pi, the BrickPi, the case, and all of the other parts are available in the BrickPi 3 Starter Kit. You will need some Linux command-line expertise and a decent amount of manual dexterity to put all of this together, but if I did it then you surely can.
Greengrass in Action I can access Greengrass from the Console, API, or CLI. I’ll use the Console. The intro page of the Greengrass Console lets me define groups, add Greengrass Cores, and add devices to my groups:
I click on Get Started and then on Use easy creation:
Then I name my group:
And name my first Greengrass Core:
I’m ready to go, so I click on Create Group and Core:
This runs for a few seconds and then offers up my security resources (two keys and a certificate) for downloading, along with the Greengrass Core:
I download the security resources and put them in a safe place, and select and download the desired version of the Greengrass Core software (ARMv7l for my Raspberry Pi), and click on Finish.
Now I power up my Pi, and copy the security resources and the software to it (I put them in an S3 bucket and pulled them down with wget). Here’s my shell history at that point:
Following the directions in the user guide, I create a new user and group, run the rpi-update script, and install several packages including sqlite3 and openssl. After a couple of reboots, I am ready to proceed!
Next, still following the directions, I untar the Greengrass Core software and move the security resources to their final destination (/greengrass/configuration/certs), giving them generic names along the way. Here’s what the directory looks like:
The next step is to associate the core with an AWS IoT thing. I return to the Console, click through the group and the Greengrass Core, and find the Thing ARN:
I insert the names of the certificates and the Thing ARN into the config.json file, and also fill in the missing sections of the iotHost and ggHost:
I start the Greengrass demon (this was my second attempt; I had a typo in one of my path names the first time around):
After all of this pleasant time at the command line (taking me back to my Unix v7 and BSD 4.2 days), it is time to go visual once again! I visit my AWS IoT dashboard and see that my Greengrass Core is making connections to IoT:
I go to the Lambda Console and create a Lambda function using the Python 2.7 runtime (the IAM role does not matter here):
I publish the function in the usual way and, hop over to the Greengrass Console, click on my group, and choose to add a Lambda function:
Then I choose the version to deploy:
I also configure the function to be long-lived instead of on-demand:
My code will publish messages to AWS IoT, so I create a subscription by specifying the source and destination:
I set up a topic filter (hello/world) on the subscription as well:
I confirm my settings and save my subscription and I am just about ready to deploy my code. I revisit my group, click on Deployments, and choose Deploy from the Actions menu:
I choose Automatic detection to move forward:
Since this is my first deployment, I need to create a service-level role that gives Greengrass permission to access other AWS services. I simply click on Grant permission:
I can see the status of each deployment:
The code is now running on my Pi! It publishes messages to topic hello/world; I can see them by going to the IoT Console, clicking on Test, and subscribing to the topic:
And here are the messages:
With all of the setup work taken care of, I can do iterative development by uploading, publishing, and deploying new versions of my code. I plan to use the BrickPi to control some LEGO Technic motors and to publish data collected from some sensors. Stay tuned for that post!
Greengrass Pricing You can run the Greengrass Core on three devices free for one year as part of the AWS Free Tier. At the next level (3 to 10,000 devices) two options are available:
Pay as You Go – $0.16 per month per device.
Annual Commitment – $1.49 per year per device, a 17.5% savings.
If you want to run the Greengrass Core on more than 10,000 devices or make a longer commitment, please get in touch with us; details on all pricing models are on the Greengrass Pricing page.
Earlier this year I told you about Cloud Directory, our cloud-native directory for hierarchical data and told you how it was designed to store large amounts of strongly typed hierarchical data. Because Cloud Directory can scale to store hundreds of millions of objects, it is a great fit for many kinds of cloud and mobile applications.
In my original post I explained how each directory has one or more schemas, each of which has, in turn, one or more facets. Each facet defines the set of required and allowable attributes for an object.
Introducing Typed Links Today we are extending the expressive power of the Cloud Directory model by adding support for typed links. You can use these links to create object-to-object relationships across hierarchies. You can define multiple types of links for each of your directories (each link type is a separate facet in one of the schemas associated with the directory). In addition to a type, each link can have a set of attributes. Typed links help to maintain referential data integrity by ensuring objects with existing relationships to other objects are not deleted inadvertently.
Suppose you have a directory of locations, factories, floor numbers, rooms, machines and sensors. Each of these can be represented as a dimension in Cloud Directory with rich metadata information within the hierarchy. You can define and use typed links to connect the objects together in various ways, creating typed links that lead to maintenance requirements, service records, warranties, and safety information, with attributes on the links to store additional information about the relationship between the source object and the destination object.
Then you can run queries that are based on the type of a link and the values of the attributes within it. For example, you could locate all sensors that have not been cleaned in the past 45 days, or all of the motors that are no longer within their warranty period. You can find all of the sensors that are on a given floor, or you can find all of the floors where sensors of a given type are located.
Just as you can do for objects, you can use Attribute Rules to constrain attribute values. You can constrain the length of strings and byte arrays, restrict strings to a specified set of values, and limit numbers to a specific range.
My colleagues shared some sample code that illustrates how to use typed links. Here are the ARNs and the name of the facet:
The first snippet creates a typed link facet called FloorSensorAssociation with sensor_type and maintenance_date attributes, in that order (attribute names and values are part of the identity of the link, so order matters):
If you’re wondering what it takes to win an ice cold pint at one of our Race to Biella events, this clip will give you more of an idea. It’s no mean feat!! Do you think you have the pedal power? Join us tonight at The Avonbridge Hotel for sunshine, cycling and, of course, a refreshing pint or two.
Glasgow-based creative content agency Bright Signals were contacted by Wire with a brief for a pretty tasty project: create something for Menabrea that ties in with the Giro d’Italia cycle race passing close to the brewery in Biella, Northern Italy.
Cycle race, was it? Menabrea brewery, you say?
The team at Bright Signals came up with the superb idea of a bicycle-powered Menabrea beer dispenser.
It must be noted that when I said the words ‘bicycle-powered beer dispenser’ aloud in the Raspberry Pi office, many heads turned and Director of Software Engineering Gordon Hollingworth dropped everything he was doing in order to learn more.
The final build took a fortnight to pull together, with Bright Signals working on the Raspberry Pi-controlled machine and Wire in charge of its graphic design.
“This was probably one of the most enjoyable builds I’ve worked on,” says Bright Signal’s Deputy Managing Director, Grant Gibson. “We had a really clear idea of what we were doing from the start, and we managed to reuse loads of parts from the donor bicycle as we simplified the bike and built the pouring system.” The team integrated the bottle cage of the donor bike into the main dispensing mechanism, and the bike’s brake levers now cradle a pint glass at the perfect angle for pouring.
A Raspberry Pi powers the 24″ screen atop the beer dispenser, as well as the buttons, pouring motors, and lights.
Perfect size for the Raspberry Pi lobby! Image c/o Grant Gibson
Giro di Scozia
Fancy trying Menabrea’s bicycle-powered beer dispenser for yourself? The final stop of its 4-week tour will be the Beer Cafe in Glasgow this Friday 2nd June. If you make it to the event, be sure to share your photos and video with us in the comments below, or via our social media channels such as Twitter, Facebook, and Instagram. And if you end up building your own beer-dispensing cycle, definitely write up a tutorial for the project! We know at least one person who is keenly interested…
The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.