BUY IN PRINT WORLDWIDE MAGPI.CC/STORE Issue 89 January 2020 magpi.cc The official Raspberry Pi magazine 5555 0000 KIT & GADGET GUIDE BUILD A SMART ROBOT This wheeled racer responds to colours CONNECT MACHINE A CLASSIC LEARNING COMPUTER FOR KIDS TO THE WEB Build a smart Add internet to a RASPBERRY PI classroom retro computer assistant TIPS & TOOLS £5.99 GRILL SANDWICHES Kickstart your new e r o WITH CHEESEBORG t s / c THE CUTIEPI TABLET project for 2020 pi.c g MAKE AN AIRDRUM BEATBOX a m 41 PAGES OF PROJECTS & TUTORIALS 191014_BRAIN_MAGPI_UK.indd 1 10/2/19 10:38 AM WELCOME WELCOME to The MagPi 89 R aspberry Pi is unlike any other computer. On the one hand, it’s a fully powerful desktop computer, at a fraction of the regular R Lucy O Hattersley cost. At the same time, thanks to its educational roots, Raspberry T I D Pi is ready to become just about anything. Everything from solar- E Lucy is editor of The MagPi and cat powered boats (page 8) to cheese-grilling machines (page 16) can be whisperer. This month she’s dressing found inside this magazine. up as a pantomime horse and running Maybe you’ve got an idea for something to make. In which case around Greenwich. our 50 Tips & Tools for Raspberry Pi feature (page 26) will help you As you do. magpi.cc kit out for 2020. This year could be your chance to finally build your crazy contraption. If, like me, you’ve no idea what to make next, then take a look at our Raspberry Pi 4 accessories guide (page 68). Here you’ll find kits and GGEETT AA gadgets that can inspire you to build a friendly project. I believe 2020 is going to be an incredible year for technology and RRAASSPPBBEERRRRYY making, and The MagPi sits at ZZEERROO WW KKIITT the heart of the most creative PAGE 24 community on earth. This magazine is packed with incredible ideas and builds engineered by some of the most fun people we know. Here’s to another decade of making. Lucy Hattersley Editor mmaaggppii..cccc 0033 Contents > Issue 89 > January 2019 Cover Feature 26 Tips & Tools 55550000 5500 Regulars 06 World of Raspberry Pi 92 Your letters 97 Next Month 98 The Final Word Project Showcases RASPBERRY PI 4 08 AMOS sailboat 12 Organnery pipe organ 14 Airdrum TIPS & TOOLS 16 Cheeseborg 20 CutiePi 26 22 Bit Time Rotary Dial Phone 8 16 Aquatic Mini Observation System Cheeseborg DISCLAIMER: Some of the tools and techniques shown in The MagPi magazine are dangerous unless used with skill, experience, and appropriate personal protection equipment. While we attempt to guide the reader, ultimately you are responsible for your own safety and understanding the limits of yourself and your equipment. Children should be supervised. Raspberry Pi (Trading) Ltd does not accept responsibility for any injuries, damage to equipment, or costs incurred from projects, tutorials or suggestions in The MagPi magazine. Laws and regulations covering many of the topics in The MagPi magazine are different between countries, and are always subject to change. You are responsible for understanding the requirements in your jurisdiction and ensuring that you comply with them. Some manufacturers place limits on the use of their hardware which some projects or suggestions in The MagPi magazine may go beyond. It is your responsibility to understand the manufacturer’s limits. 38 64 Tutorials 38 Add navigation to a robot 44 Smart classroom assistant 48 Vintage computer internet 52 Hack GraviTrax – part 3 Add navigation to a robot Design a 3D printer pendant 60 C and GTK custom widgets 48 64 Design a 3D printer pendant The Big Feature 68 Add internet to a vintage computer Raspberry Pi kit & gadget guide 84 Reviews 76 Enviro 78 SmartiPi Touch 2 80 Top 10 advanced projects 82 Learn R with Raspberry Pi Community 84 Andrew Suttle interview 86 This month in Raspberry Pi Andrew Suttle interview 90 Events calendar WIN RASPBERRY PI 4 95 ONE OF & CASE BUNDLES FIVE THE WORLD OF RASPBERRY PI A kestrel captured at night-time using Raspberry Pi NoIR infrared camera The Nest Box live-streams garden birds This Springwatch-inspired nest box is used to lure Facebook users, such as Rosie Hattersley, away from cute cat videos I t’s a tried and tested social media formula: Liverpool-based Jamie introduces viewers to cute animals doing adorably cute things – or the cute residents of The Nest Box using just being cuddly and wholesome. Click impressively high-quality images and video from ‘like’ and share the heart-melting gorgeousness three Raspberry Pi-enabled British bird-boxes, of the latest viral video. No wonder The MagPi with three more being set up. magazine reader Jamie Wainwright’s live stream These train video cameras on a kestrel box and of chicks in a nesting box caught our attention also a barn owl box after Jamie proposed the when we asked you about Raspberry Pi projects. camera feed to the Wirral Barn Owl Trust. Instant replay A PIR sensor and camera fitted to a Throughout spring, all the cameras stream live to kestrel box The Nest Box’s 5500 Facebook wildlife fans The CAD design for (magpi.cc/nestbox). Out of season, visitors can the plastic tray at the enjoy a short movie recapping events from the top of a bird-box nests earlier in 2019: magpi.cc/nestboxmovie. Jamie says one of the beauties of The Nest Box setup is that it requires so little equipment: a Raspberry Pi and Camera Module, along with a Raspberry Pi PoE HAT (magpi.cc/poe) to provide both power and internet connectivity, so there’s 06 magpi.cc The Nest Box live-streams garden birds THE WORLD OF RASPBERRY PI The Nest Box houses a Raspberry Pi, Camera Module, and PoE (Power- over-Ethernet) HAT Facebook goes into live streaming mode whenever there’s any nest box action T he design for the kestrel box, with the camera in the lower section only one cable connection to weather-proof. A custom HAT controls LED lights and the Raspberry Pi Camera Module, providing high- quality images day and night. Python code records visitors to the nest boxes. This causes the Facebook feed to go into live streaming mode E ach installation has whenever there’s any nest box action. a different design depending on the bird being monitored Creature comforts – this one is for the Thanks to some successful crowdfunding, Jamie barn owl box was able to add sound via USB microphones A 3D-printed section for the barn owl box attached to the Raspberry Pi rig. Furthermore, a schematic on The Nest Box’s GoFundMe page (magpi.cc/nestboxfund) shows the smart bird-box’s electronics hidden away in a small plastic box, with a fan to help keep everything cool during operation. The Nest Box live-streams garden birds magpi.cc 07 PROJECT SHOWCASE Aquatic Mini Observation System What computer do you use when you want to have a solar-powered, autonomous boat that measures water quality? Rob Zwetsloot discovers that the answer is Raspberry Pi T here are many basic rules when it comes to “During this past winter, I built a second electronics. One of them is that water and prototype, this time using a longer surfboard- electronics don’t mix, even if your average type design constructed from glued-together smartphone is able to take a brief dunk in the sink insulation foam that was given a coat of fibreglass these days. So when someone comes to us talking to give it some added strength and stiffness,” about a waterborne project, we listen – and that’s Murray explains. “Instead of the water propellers, exactly what happened when Murray Lowery-Simpson a single 10-inch drone propeller and motor were R Murray emailed us about his solar-powered boat. used and connected to a small waterproof servo KE Lowery- “My project is named AMOS (Aquatic Mini motor at the stern end of the boat. This design was A Simpson Observation System),” Murray tells us. “It is a solar- lighter (about 13 kg) and longer, and although the M powered, autonomous airboat for measuring water air propeller only produced about a tenth of the Although coming quality over large, distributed areas.” thrust provided by the dual water propellers, the from an engineering Murray has worked on a couple of prototypes for improved draft and hydrodynamic shape made it background, Murray has been the boat. The first one was made out of a kayak beer slightly faster in the water.” developing cooler (a small kayak that acts as a beer cooler) and A Raspberry Pi controls the speed and angle of software for a little had propellers that would end up getting gunked up. the air propeller, takes sensor readings from the over 20 years. He also tested distance measuring with a Raspberry Pi water, interacts with the lidar module, and has innaturerobotics.com Compute Module’s stereo vision before settling on a several other functions so that it knows its speed lidar module and a Raspberry Pi 3B+. and heading. A MOS will be useful to researchers, and a good base for hobbyists 08 magpi.cc Aquatic Mini Observation System PROJECT SHOWCASE The boat is fully automated and, on a sunny day, fully self-sufficient Quick FACTS > Murray got into robotics in late 2017 > He was inspired by local news about A lidar and camera pollution on aid in navigation public beaches > AMOS tests pH, salinity, dissolved oxygen, turbidity, and more A suite of sensors check the water’s chemistry – soon it > Pictures from the will test for bacteria Camera Module are mostly used to locate a lost AMOS > AMOS can be controlled by iOS and Android devices T he old version was a bit slower and stubbier, and the fans would get weeds stuck in them Aquatic Mini Observation System magpi.cc 09 PROJECT SHOWCASE T his photo gives you “I’m hoping that AMOS will be used for water an idea of the size of the boat testing by environmental services companies, and industrial customers such as mine operators that may be required by law to confirm that pollution limits in bodies of water surrounding their operations are not exceeded,” Murray reveals. “I’m hoping also to be able to offer it at an attractive price point, with modular components so that researchers or robotic boat enthusiasts could also use it, or some subset of it, in their own projects.” A pproximately 150 km of testing has been completed on the second AMOS prototype Major tests The prototypes aren’t just proofs of concept, either: they’re fully functioning test beds, as Murray explains: “Approximately 150 km of testing has been completed on the second AMOS prototype in 2019. It can work well in shallow water (as little as 2 cm depth) and can travel through regions of water with lots of grass or other vegetation without any worries about getting stuck. Its airboat design works best under conditions of low wind (less than 20 km/h) and it can travel at a top speed of about 2.7 knots (5 km/h). Provided the sun is shining on a clear day and higher than about 40 degrees in the sky, AMOS can run at top speed without depleting the charge of its battery.” Murray plans for AMOS to be on sale in the summer, so you don’t have too long to wait. Our interview with Murray covered many more topics we couldn’t squeeze into the magazine, so please look out for the full transcript at magpi.cc/amos. 10 magpi.cc Aquatic Mini Observation System