BUY IN PRINT WORLDWIDE MAGPI.CC/STORE
Issue 74
October 2018
magpi.cc
The official Raspberry Pi magazine
BUILD A LAPTOP Media Centre Kits
Code Space Invaders Recreate this classic in Python
Plus Grow veggies with the Aquaponic Garden Play Rock, paper scissors with AI Table football scoreboard
Haunted
Hacks CreePi projects for Halloween
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WIN!
Digital making on the go with Raspberry Pi
Make a Washing Line Sensor Keep your clothes dry
New Picade | Top 10 Cases | QuickStart guide
Code
Design
Configure
Analyze
Now free for home projects A professional control system development tool
CDP Studio is a development platform for industrial control systems, now coming with a free version for non-commercial use. The system can run on a Raspberry Pi, supports C++, open source libraries and has a large feature toolbox including GPIO, I2C and MQTT. Its built in GUI design tool and features lets you code less and do more. Free download on www.cdpstudio.com
CDP Technologies AS Nedre Strandgate 29 P.O. Box 144 NO-6001 Ă…lesund, Norway
Tel: +47 990 80 900 info@cdptech.com www.cdpstudio.com
WELCOME
WELCOME to the new look MagPi
Lucy Hattersley Editor
EDITOR
R
egular readers will notice a big change this month. We’ve been working hard on this issue for many months; so, welcome to your amazing new look version of The MagPi. We believe The MagPi is the best computer magazine on the newsstand. Every issue is packed with physical computing advice, code, and the most amazing projects from the greatest computer community on Earth. So how do you make the best computer magazine even better? Throughout this edition, you’ll find bigger photographs of brilliant community projects; the latest Raspberry Pi product information; cleaner and clearer fonts for both text and code; and a fresh new design that’s brighter than ever. We’ve made space for bigger features on the most important Raspberry Pi computing projects, tutorials, and reviews. In short, The MagPi is better than ever. We hope you love this new look as much as we do.
Lucy Hattersley Editor of The MagPi. Lucy codes, crafts, and creates wonky robots. She speaks French (badly) and mangles the piano. One day she’ll get that pet dog. magpi.cc
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PS: We’re 75 issues young next month. Stay tuned!
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CONTENTS
Contents > Issue 74 > October 2018
Cover Feature
20 Build your
own laptop
20
Regulars
06 News 66 Technical FAQ 94 Your letters 98 Final word Project Showcases
08 12 14 16 18
Aquaponic Garden PiCam Marine camera FRILLER robot Table Foosball Rock, Paper, Scissors
PiCam Marine camera
16
Table Foosball
12
32
Pygame Zero Invaders
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.
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CONTENTS
80
Top 10 Pi Cases
14
Tutorials
32 Pygame Zero Invaders 40 Pi Bakery: Matrix – part 2 46 Laundry-saving rain detector 50 Minecraft with Wolfram 56 Make games in C – part 10 60 Pi QuickStart guide The Big Feature
68
FRILLER robot
78
76
Reviews
76 Picade 78 Kitty Ears 80 10 best Raspberry Pi cases 82 Learn C with Raspberry Pi Community
Kitty Ears
WIN One of Five Pi Switch Caps
Picade
86 Interview 88 This month in Raspberry Pi 92 Events
96 In association with
with an OLED display and weather pack!
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THE WORLD OF PI
EMF festival powered by Raspberry Pi network LimeSDR guarantees no rain on the parade of electronic making, reports Rosie Hattersley
T
he Electromagnetic Field festival (emfcamp.org) has become a magnificent summer highlight among makers, scientists, engineers, and crafters. Held over the August bank holiday weekend in the grounds of Eastnor Castle, Herefordshire, Electromagnetic Field (EMF) is a magnificent celebration of all things inspirational and DIY design and makable. Organisers describe it as a “camping festival with a power grid and highspeed internet access; a temporary village of geeks, crafters, and technology enthusiasts.� Come night-time, EMF turns into a brightly lit festival more akin to a traditional music weekender.
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EMF festival powered by Raspberry Pi network
A LimeSDR mounted base station providing GSM for EMF festival-goers ixteen Pi-powered S base stations, boxed up and ready to deploy at the festival
THE WORLD OF PI
Weatherproofing the boards was essential, given the British weather Inside the base station is a Raspberry Pi 3B+ and LimeSDR board
But electrical and electronic kit does not obviously lend itself to being assembled and demonstrated in a rural field, particularly when said field is situated in the British countryside. Chancing the great British summer with millions of pounds’ worth of people’s highly personal tech
T he base stations combined a LimeSDR Mini board with a Raspberry Pi 3 Model B+ at stake is a foolhardy venture. Not only that, but even festival-goers’ badges are tech-heavy. Entry depends on a badge that is also a full-blown microcontroller, with WiFi and an LCD screen, that participants can take home and reprogram.
Mobile connectivity
Sensibly enough, the organisers of EMF not only recruited a mobile communications network provider to ensure internet connectivity for festival-goers, but they also weatherproofed the entire shebang. Lime Microsystems (limemicro.com) put together a self-contained GSM network and wireless infrastructure consisting of 16 weatherproof base stations. The base stations combined a LimeSDR Mini board with a Raspberry Pi 3 Model B+ host running Linux on
a fully open-source GSM base station (BTS) stack and Osmocom cellular network software. The mounted base stations enjoyed a mains power supply, via a 24 V adapter and DC-DC converter, making it critical that their Raspberry Pi enclosures were fully waterproof and allowed no moisture to ingress. The upshot: the festival’s technological mavens could confidently show off their innovations and ideas with no fear of rain stopping play.
EMF festival powered by Raspberry Pi network
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MAKER
PROJECT SHOWCASE
Aquaponic Domestic Garden
Diego Braga An IT DevOps engineer with a passion for automation and IoT projects.
@braghettos
Growing veggies indoors when you’re not always there is easy when you have a Raspberry Pi and a guard fish. Rob Zwetsloot learns more
“L
iving in a big city has pros and cons,” Diego Braga tells us. “One of the cons I suffered most is not having a small organic garden.” Diego lives in Milan, in a small apartment with a smaller balcony that he spends a lot of time away from. That didn’t stop him wanting to grow some fresh veg for himself, though, and he looked at hydroponic gardens to see if that was a solution. “One of the cons of this approach is that you need to feed fertiliser in the water, and that’s
S itting in a corner of the living room, the mini garden takes up very little space
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Aquaponic Domestic Garden
something that, even if it can be automated, is not self-sufficient,” Diego explains. “In 2015, EXPO Italy took place and in a pavilion there was an aquaponics system in which plants and fishes were living close and feeding each other. I started to study the aquaponics system and it blew my mind: two different ecosystems (the aquarium with fishes and plants in the solid earth) can feed each other. The waste of one is the nourishment of the other. That was what I wanted.”
PROJECT SHOWCASE
The plants get light from the various lamps surrounding the system
Fish waste is pumped up to the plant to be used as fertiliser
Quick FACTS > Diego spent two and a half years making his garden > The fish’s name is Qwerty > Every night, the garden sends a report to Diego about the soil
A little fish manages to help keep the system in balance, getting nutrients from the plant as well as helping it grow
> Monitoring the garden from his phone was one of his requirements > It’s also designed to be aesthetically pleasing, part of the furniture
Aquaponic Domestic Garden
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PROJECT SHOWCASE
T here are a lot of sensors required to keep the system working well
A prototype setup
for the system using IKEA parts
Diego figured all he’d then have to automate is the cleanliness of the aquarium, and decided to do it and collect sensor data via IBM Watson’s IoT platform. It took him a while to figure out how. “First of all, I had to study a solution to keep the aquarium clean. The fish waste is the perfect nourishment for the plants and this waste lies on the bottom of the aquarium. One night I had an inspiration: use an X-Y plotter and, instead of
writing on a surface, use a submersible pump to collect all the waste and deliver it to the plants.”
Pump it up Building the shelves
to house everything properly takes some custom work
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Aquaponic Domestic Garden
Using an IKEA shelf with the aquarium at the bottom and pot on the shelf above, the waste water is pumped up to the plant, which then uses it and pH-balances the water, while gravity allows nutrients to drop down to the fish.