Kategorie: Linux

A robotic beast

A serious robot, the DiddyBorg (£220 / $299) is diddy in name only and a true Raspberry Pi automated monster. Program it, remote-control it, or just have it sitting pretty in your workshop. Your choice.

PiGrrl 2

DIY handheld gaming

We’ve covered this project in a previous issue of The MagPi, but this project deserves mentioning again: with some 3D-printed parts, and some ingenious Adafruit PCB parts, you too can make a handheld console (£56 / $60).

Retro-cool at home

This big build by Bob Clagett is incredibly thorough, and shows you how to build a wooden arcade cabinet from scratch, complete with lights and cool art.

Pinball table

High score mania

If an arcade machine is a bit too new for you, how about something a bit more classic and physical like a pinball table? This one repurposes an old bed.

Raspberry Pi classic

This kind of project is a classic among the community, especially as the mirror software part is so easily done. Building a frame is quite fun and a great first-time carpentry project.

Take Raspberry Pi anywhere

This tiny laptop project allows you to bring your Raspberry Pi with you wherever you want to go, and do some work while you’re there.

Home assistant

Voice-controlled computer

A number of big voice services are available on Raspberry Pi. Alexa is one of the easiest to get onto Raspberry Pi, thanks to the excellent AlexaPi software.

Scan your friends

This big project is great for showing off at your local Raspberry Jam or maker event. It takes a lot of Raspberry Pi boards and cameras to create the project, but it does capture impressive 3D scans.

3D printer controller

Futuristic plastic printing

Have a new 3D printer? How about interfacing it with Raspberry Pi using the amazing OctoPrint? It’s especially helpful if you think of something cool to print while on the go.

Smart CCTV system

Recognise your visitors

CCTV cameras with Raspberry Pi are not too difficult to put together. We like this project as it uses computer vision and face detection to recognise known people as well.

Learn to program

Got the tools and the skills to raise a barn and then some, but lacking the ability to print ‘Hello World’? Take a look at our books on controlling electronics with Python and GPIO Zero and learning C.

The bulletin boards of the 1980s haven’t died out quite yet, but they have gone online. There’s only a handful of BBSes (bulletin board systems) that you can dial up with your old-time modem.

If you like the idea of accessing an internet-based BBS from your Atari ST, Amiga, or BBC Micro, then we can use a Raspberry Pi computer to act as a translator. You can even use modern services like Twitter! All we need to do is get Raspberry Pi talking in one of the most popular communications protocols of all time: RS232.

A little history

Every Raspberry Pi computer has a form of serial access, which is one of the oldest and simplest ways of communicating with computers. These days you’re more likely to use TCP/IP, the protocol of the internet, to chat to a remote device, but back in the day it was RS232 that ruled the communications world.

Raspberry Pi circuitry features a further simplified version often referred to UART (universal asynchronous receiver/transmitter) running at 3.3 V, but we can adapt it to ‘full’ RS232 at 12 V so that older computers can handle the signal.

You’ll need

Top tip 1: Not just vintage

This project works well with older PCs. Although they refer to them as COM ports, their 9-pin connectors are really RS232.

Top tip 2: Be careful of weird wiring

Do your research on your choice of classic machine. Some, such as the Cambridge Z88, use non-standard wiring to their connectors.

Study and shop

To ‘downgrade’ a Raspberry Pi to RS232, we’ll need to build a small circuit to act as a transceiver so the vintage computer can ‘hear’ our virtual modem and the RS232 signals do not fry our delicate Raspberry Pi board. Luckily, all the heavy lifting for such a job can be done by the MAX3232CPC integrated circuit. All you need to do is wire it up, add a few capacitors, and you’ll be BBSing in no time.

Have a look at the circuit diagram in Figure 1. We’ve deliberately made it larger than it needs to be for simplicity. More experienced makers will be able to reduce it in size if they wish.

Soldering the main circuit

Time to get building. Thankfully, the circuit itself is not very complicated, but it’s also unforgiving, so make sure all the wiring is in the correct place or nothing will work! We recommend starting with the IC socket, then the wiring, followed by the capacitors, finishing with the headers (optional if you’d like to use jumper cables). The result takes the two transmit (TX) and receive (RX) lines from the GPIO and feeds them into the IC. The MAX3232CPC converts the data into RS232 standard and outputs them to the 9-pin D connector and vice versa. Check and double-check everything.

Add connectors

Unless you’re going for a permanent setup or looking to make it as low-profile as possible, we recommend using DuPont-style jumper cables to connect the circuit to your GPIO. Which model of Raspberry Pi you use is up to you, but unless you have a specific use case in mind, a Raspberry Pi Zero W is the perfect choice as it’s small and there’s little horsepower required. You will also need to solder up the 9-pin D connector. The diagram (Figure 1) shows the connector from the solder (rear) side. Make sure you wire up correctly to pins 2 and 3 and ground it too.

Raspberry Pi time

Your Raspberry Pi Zero W will need a bit of configuration before you can get going. Start with a fresh microSD card with Raspbian Lite (we don’t need a desktop, but feel free to install ‘full’ Raspbian if you wish). This is also a great project for reusing any old low-capacity microSD cards you have, as there’s not much software to install. Once booted up, make sure everything is up to date by running sudo apt -y update && sudo apt -y upgrade. Time to grab a refreshing beverage as Raspbian applies all the latest updates.

Prepare your virtual modem

An ‘out of the box’ Raspbian installation isn’t quite ready to go back to the 1980s just yet, so we need to do a little further configuration. From the command line, run sudo raspi-config to start the Raspberry Pi configuration utility. From the top of the menu, start by changing your password (optional, but recommended); then, under Network Options, set your host name (again, optional) and configure WiFi. Finally, under Interfacing Options, enable SSH and Serial. When asked ‘Would you like a login shell’, select ‘Yes’. Now exit the utility and shut down the computer (sudo shutdown).

Testing time

Check your circuit board for any short circuits or dry solder joints. Once happy, connect it to the GPIO. There are four connection points: one for 3.3 V (physical pin 1), ground (pin 9), and TX/RX (pins 8 and 10 respectively). We recommend getting an RS232/USB cable and testing with a modern computer first. Connect the 9-pin connectors together and boot your Raspberry Pi. Now, using your favourite Terminal emulator program (we like Serial for macOS), try to connect over RS232. Raspbian’s default settings are 115,200bps (connection speed), eight data bits, no parity, one stop bit (aka 8N1).

Troubleshooting

Having problems? RS232 can be a tricky beast as, unless everything is perfect, nothing will work at all. The most common issue will be polarity of the TX and RX lines. For things to work, the RX of the GPIO must be connected via the MAX3232CPC to the TX line of the computer and vice versa.

Start by checking that your speed is correct and the protocol is set for 8N1. Also try ‘reset’ or ‘send break’ in your terminal emulator, which is sometimes needed to wake up the connection. Finally, try using a null modem cable (which crosses over the lines) or swapping the connectors to pins 8 and 10.

Get online

If everything is working, you should now be greeted with the Raspbian terminal login (you might need to press ENTER a couple of times to wake it up). You can now log in as normal. If the connection is behaving, feel free to try it out on a real vintage machine. Some may require adapters to connect (1990s home computers favoured 25-pin D connectors).

You will probably need to reduce the speed of the connection, as many older computers cannot handle the default 115,200bps. Unless your computer is very old, 9,600bps will probably work. To set the port to this, enter the following from an SSH session:

sudo stty -F /dev/serial0 9600

Connect to a BBS

Almost every BBS is now online and ‚talks‘ using a protocol called Telnet. It is very insecure, sending plain text over the internet and has since been replaced with SSH (Secure Shell). However, many of these services are being run on original equipment that has no support for SSH, so Telnet it is.

The Telnet client software is not installed by default, so run sudo apt install telnet. Once finished, try connecting to the popular Particles BBS (running on an Apple II/e!), by entering:

telnet particlesbbs.dyndns.org 6400

Within a few seconds you’ll see a welcome message. After you’ve had a look around, use CTRL+] followed by ‘exit’ to leave Telnet.

Emulate a classic modem

If you want a genuine experience, and full compatibility with vintage BBS software, it’s easy to emulate the classic Hayes AT command-set. To install the emulator:

sudo apt install tcpser

Before running tcpser, go back into raspi-config, select ‘Interfacing Options’, then ‘Serial’, and answer ‘No’ when asked if you want a login shell to be accessible and then ‘Yes’ if you want the serial port to be enabled. Now start tcpser using SSH:

tcpser /dev/serial0 -s 9600 -l 7

(You can change 9600 to be your desired speed).

Try connecting over serial again and this time you’ll be able to enter AT commands, replacing phone numbers with domain names.

Do more!

Your original ‘comms’ software should be blissfully unaware that it is talking over the internet. There’s now another web of vintage BBSes to explore on your original machine, but why stop there? The Raspbian repositories are full of command-line software that can be accessed by your classic machine. Tweeting from an old 8-bit is always fun, so why not install ‘t’, a command-line Twitter client (github.com/sferik/t)?

Of course, you can now do anything in the Raspbian shell that you can in an SSH session, so get your BBC Model B to operate LEDs and switches, or have your Commodore Amiga send Telegram messages!

The bulletin boards of the 1980s haven’t died out quite yet, but they have gone online. There’s only a handful of BBSes (bulletin board systems) that you can dial up with your old-time modem.

If you like the idea of accessing an internet-based BBS from your Atari ST, Amiga, or BBC Micro, then we can use a Raspberry Pi computer to act as a translator. You can even use modern services like Twitter! All we need to do is get Raspberry Pi talking in one of the most popular communications protocols of all time: RS232.

A little history

Every Raspberry Pi computer has a form of serial access, which is one of the oldest and simplest ways of communicating with computers. These days you’re more likely to use TCP/IP, the protocol of the internet, to chat to a remote device, but back in the day it was RS232 that ruled the communications world.

Raspberry Pi circuitry features a further simplified version often referred to UART (universal asynchronous receiver/transmitter) running at 3.3 V, but we can adapt it to ‘full’ RS232 at 12 V so that older computers can handle the signal.

You’ll need

Top tip 1: Not just vintage

This project works well with older PCs. Although they refer to them as COM ports, their 9-pin connectors are really RS232.

Top tip 2: Be careful of weird wiring

Do your research on your choice of classic machine. Some, such as the Cambridge Z88, use non-standard wiring to their connectors.

Study and shop

To ‘downgrade’ a Raspberry Pi to RS232, we’ll need to build a small circuit to act as a transceiver so the vintage computer can ‘hear’ our virtual modem and the RS232 signals do not fry our delicate Raspberry Pi board. Luckily, all the heavy lifting for such a job can be done by the MAX3232CPC integrated circuit. All you need to do is wire it up, add a few capacitors, and you’ll be BBSing in no time.

Have a look at the circuit diagram in Figure 1. We’ve deliberately made it larger than it needs to be for simplicity. More experienced makers will be able to reduce it in size if they wish.

Soldering the main circuit

Time to get building. Thankfully, the circuit itself is not very complicated, but it’s also unforgiving, so make sure all the wiring is in the correct place or nothing will work! We recommend starting with the IC socket, then the wiring, followed by the capacitors, finishing with the headers (optional if you’d like to use jumper cables). The result takes the two transmit (TX) and receive (RX) lines from the GPIO and feeds them into the IC. The MAX3232CPC converts the data into RS232 standard and outputs them to the 9-pin D connector and vice versa. Check and double-check everything.

Add connectors

Unless you’re going for a permanent setup or looking to make it as low-profile as possible, we recommend using DuPont-style jumper cables to connect the circuit to your GPIO. Which model of Raspberry Pi you use is up to you, but unless you have a specific use case in mind, a Raspberry Pi Zero W is the perfect choice as it’s small and there’s little horsepower required. You will also need to solder up the 9-pin D connector. The diagram (Figure 1) shows the connector from the solder (rear) side. Make sure you wire up correctly to pins 2 and 3 and ground it too.

Raspberry Pi time

Your Raspberry Pi Zero W will need a bit of configuration before you can get going. Start with a fresh microSD card with Raspbian Lite (we don’t need a desktop, but feel free to install ‘full’ Raspbian if you wish). This is also a great project for reusing any old low-capacity microSD cards you have, as there’s not much software to install. Once booted up, make sure everything is up to date by running sudo apt -y update && sudo apt -y upgrade. Time to grab a refreshing beverage as Raspbian applies all the latest updates.

Prepare your virtual modem

An ‘out of the box’ Raspbian installation isn’t quite ready to go back to the 1980s just yet, so we need to do a little further configuration. From the command line, run sudo raspi-config to start the Raspberry Pi configuration utility. From the top of the menu, start by changing your password (optional, but recommended); then, under Network Options, set your host name (again, optional) and configure WiFi. Finally, under Interfacing Options, enable SSH and Serial. When asked ‘Would you like a login shell’, select ‘Yes’. Now exit the utility and shut down the computer (sudo shutdown).

Testing time

Check your circuit board for any short circuits or dry solder joints. Once happy, connect it to the GPIO. There are four connection points: one for 3.3 V (physical pin 1), ground (pin 9), and TX/RX (pins 8 and 10 respectively). We recommend getting an RS232/USB cable and testing with a modern computer first. Connect the 9-pin connectors together and boot your Raspberry Pi. Now, using your favourite Terminal emulator program (we like Serial for macOS), try to connect over RS232. Raspbian’s default settings are 115,200bps (connection speed), eight data bits, no parity, one stop bit (aka 8N1).

Troubleshooting

Having problems? RS232 can be a tricky beast as, unless everything is perfect, nothing will work at all. The most common issue will be polarity of the TX and RX lines. For things to work, the RX of the GPIO must be connected via the MAX3232CPC to the TX line of the computer and vice versa.

Start by checking that your speed is correct and the protocol is set for 8N1. Also try ‘reset’ or ‘send break’ in your terminal emulator, which is sometimes needed to wake up the connection. Finally, try using a null modem cable (which crosses over the lines) or swapping the connectors to pins 8 and 10.

Get online

If everything is working, you should now be greeted with the Raspbian terminal login (you might need to press ENTER a couple of times to wake it up). You can now log in as normal. If the connection is behaving, feel free to try it out on a real vintage machine. Some may require adapters to connect (1990s home computers favoured 25-pin D connectors).

You will probably need to reduce the speed of the connection, as many older computers cannot handle the default 115,200bps. Unless your computer is very old, 9,600bps will probably work. To set the port to this, enter the following from an SSH session:

sudo stty -F /dev/serial0 9600

Connect to a BBS

Almost every BBS is now online and ‚talks‘ using a protocol called Telnet. It is very insecure, sending plain text over the internet and has since been replaced with SSH (Secure Shell). However, many of these services are being run on original equipment that has no support for SSH, so Telnet it is.

The Telnet client software is not installed by default, so run sudo apt install telnet. Once finished, try connecting to the popular Particles BBS (running on an Apple II/e!), by entering:

telnet particlesbbs.dyndns.org 6400

Within a few seconds you’ll see a welcome message. After you’ve had a look around, use CTRL+] followed by ‘exit’ to leave Telnet.

Emulate a classic modem

If you want a genuine experience, and full compatibility with vintage BBS software, it’s easy to emulate the classic Hayes AT command-set. To install the emulator:

sudo apt install tcpser

Before running tcpser, go back into raspi-config, select ‘Interfacing Options’, then ‘Serial’, and answer ‘No’ when asked if you want a login shell to be accessible and then ‘Yes’ if you want the serial port to be enabled. Now start tcpser using SSH:

tcpser /dev/serial0 -s 9600 -l 7

(You can change 9600 to be your desired speed).

Try connecting over serial again and this time you’ll be able to enter AT commands, replacing phone numbers with domain names.

Do more!

Your original ‘comms’ software should be blissfully unaware that it is talking over the internet. There’s now another web of vintage BBSes to explore on your original machine, but why stop there? The Raspbian repositories are full of command-line software that can be accessed by your classic machine. Tweeting from an old 8-bit is always fun, so why not install ‘t’, a command-line Twitter client (github.com/sferik/t)?

Of course, you can now do anything in the Raspbian shell that you can in an SSH session, so get your BBC Model B to operate LEDs and switches, or have your Commodore Amiga send Telegram messages!

“My first Raspberry Jam was CamJam in autumn 2013, when I showed some programs I had written,” Andrew tells us. “I also enjoy developing robots and doing electronics. I first went to the Colchester club run by John Woods in 2016, when I built a robot car using a Raspberry Pi. The Colchester club is run at the university and I like going there very much. The lab we use has all new oscilloscopes and I used them recently with some op-amp circuits. I also built my own oscilloscope from a kit and John Woods helped me get it working, as I had not soldered one of the connections properly. I took my oscilloscope into school and used it there.”

Andrew isn’t the only young person at the club, either: “Several other children from my school have also gone to the club and I have built projects with them. We made an ‘I ♥ Pi’ team and entered competitions. We also had a ‘Pi Rates’ team. My brother also goes to the club. He is building a security project with Arduino, and I might use some of his ideas in a programming course I am making.”

What kind of people attend?

At the moment, it is all children aged 8 to 14 who come along with their parents, but we don’t have set age limits. The youngest children usually want to learn Python; the older children usually have a project of their own that they want to work on. People often drop in for a few sessions and solve a particular problem and then stop attending. We have had some stay for years and they are all from different local schools.

One boy, Taylor, came regularly until he was 18. He developed several AI projects. He got a scholarship to Cambridge University, and graduates this year.

Other members have entered competitions and we have had members win in the ‘BigBang’, ‘Pioneers’, and ‘EasternDigital’ competitions. EasternDigital is an ‘adult’ competition for companies and one of the winners three years ago was ten years old; he was too young for their children’s competition!

What projects have you or other people made there?

As well as the AI projects I have mentioned, we have had members developing robotic arms. Then there was a flight control system for model aircraft and several robot cars.

Several children have gravitated towards embedded systems. Two children, Zara and Andrew, developed a plant monitoring system.

What are you working on at the moment?

Some of the younger children who are new to the club are doing directed tasks. Samuel, aged eight, and Xingtong, aged eleven, are both working on TicTacToe. But we do very little teaching.

Some children are doing their own Python projects, with Python always a popular language. Robyn, aged twelve, has made a Mastermind-style game linked with Hangman. Andrew, now aged 14, has developed a version of Conway’s game of life.

There are also several Arduino projects on the go. Victor, aged eleven, has just finished his security control system which is based on an Arduino Uno and written in C.

There are always robots. We have a robot arena that is purpose-built for the development of robots, and we have a lot of knowledge and resources to support a robot project. The arena is 100 square metres in area, and has a six-metre-high ceiling to accommodate flying robots.

Making a splash with your final-year university project can be the ideal way to gain the attention of potential employers and land yourself your dream job. Appealing to your lecturers’ and classmates’ stomachs is also a pretty effective way of getting them onside.

Hearing from Taylor Tabb about the robot project he and friends Mitchell Riek and Evan Hill cooked up for their mechanical engineering degree, it’s little surprise to learn that having graduated in the summer of 2019, he’s already embarked on a fantastic-sounding Raspberry Pi-focused career.

Taylor studied mechanical engineering at Carnegie Mellon University, exploring how people interact with hardware, and thinks Raspberry Pi is the ideal platform for this. He now works for creative agency DeepLocal, making ‘wild and whimsical’ robots.

Say cheese!

“Cheeseborg was born out of our need to concept, design, and build a final prototype of a project in our senior engineering design class,” says Taylor. “As hungry college students awake at hours that it’s often hard to find food, we knew this was our calling – not just for us, but for grilled cheese eaters everywhere.”

Cheeseborg is a dedicated, hands-free grilled cheese making robot that will satisfy cheese cravings at all hours. The Google Assistant SDK and AIY Voice Kit provide voice activation. Both “work fantastically with Raspberry Pi 3 Model B+,” says Taylor. Their customised build of Google Assistant, sourced from the AIY Kit and Google Cloud SDK, allowed them to add some personality: you can ask about the weather while awaiting your sandwich.

Raspberry Pi also triggers its assembly, while motor control circuits and motion are operated by Arduino Mega. Taylor reveals, “We wrote our own code, but also used open-source Arduino libraries,” dictating timings and the motions for each step. Carnegie Mellon’s Department of Mechanical Engineering’s makerspace provided hardware commonly used in 3D printer kits, such as stepper motors and linear motion carriages. However, the acrylic parts were designed and laser-cut by Mitchell, Evan, and Taylor. Impressively, the project cost just $200 to build, and took approximately eight weeks to complete.

Taste test

The team undertook three weeks of customer research to identify grilled cheese preferences. “There was a lot of going back and forth between our build, CAD software, and laser cutter, adjusting parts as we learned more about the mechanics of bread and cheese,” recalls Taylor. They spent days just tuning the grilling time to get the gooeyness and crispiness just right, while experiments in applying the butter resulted in a thoroughly dairy-spattered makerspace.

Eventually, they went with a spray ‘butter’. “We aimed at the cooking plates and activated just before the bread was moved to be cooked, thus buttering both sides [not to say the rest of Cheeseborg]. In the end, we found if we just spray the grill plates every five [sandwiches] or so, it still is enough to make a crispy, gooey grilled cheese!
“

As with all good projects, we had no idea if it was going to work until 4am the morning before it was due, when Cheeseborg popped out its first fully hands-free grilled cheese sandwich.”

Making your own grilled cheese robot

1. This is the ideal project with which to use Google Assistant in Google’s Raspberry Pi AIY Voice Kit, and the Google Cloud SDK for voice activation. Experiment with phrases to initiate the snack-assembly process.

2. Raspberry Pi now hands over to Arduino. Use Arduino Mega to control the robot that assembles the grilled cheese sandwich once Raspberry Pi instructs it. Open-source Arduino libraries are invaluable here.

3. Use tongs or suction to pick up slices of bread and add a chute for the snack’s delivery. However, positioning bread to be buttered and adding cheese takes patience.

Interest levels online have been such that Taylor and his colleagues may consider offering a kit version. While he cautions that there’s a huge amount of fine-tuning involved, he says, “If anyone out there is building a grilled cheese robot, we’re more than happy to offer any insights.” Contact him at tabb.me/grilledcheese.

Warning! Hot mess!

Gooey butter is messy stuff. Be prepared for your kitchen, as well as your grilled cheese sandwich, to be buttered all over!

Quick facts

• Taylor’s first Raspberry Pi project was a ‘not great’ radio telescope

• Taylor now works with Raspberry Pi almost daily

• His business card says he’s ’sweeter than Raspberry Pi!’

• Taylor thinks there’s a whole world of culinary robots to come

• He recently made a not-so-edible bubble maker

  

The SmartiPi case is designed to work with the 7-inch official Raspberry Pi touchscreen, effectively turning a Raspberry Pi into a (bulky) tablet or fixed monitor. As there’s no real room for rechargeable batteries as standard, it works better in a more fixed environment.

One of the unique features of the SmartiPi is the interchangeable faceplates on the front of the case. As well as allowing for a Raspberry Pi Camera Module to be mounted inside the case, it enables you to add a Lego-compatible plate. It’s not large, so you can’t do much with it, but it’s a very neat addition nonetheless.

Smart build

Construction is extremely easy, just requiring you poke some ribbon cables in the right place and fasten and tighten some screws to make sure everything is mounted properly. You can choose little feet for the display, or a foldable stand so you can angle the screen – both are easy to install and even replace. There’s also a little case fan and vented rear panel to keep your Raspberry Pi cool.

It’s extremely well thought out, and a very handy case if you need a compact ‘Raspberry Pi with screen’ solution that just looks nice.

Verdict

The SmartiPi is great case if you need a stationary tablet, although making it mobile might be a little more tricky.

8/10

Raspberry Pi NAS and Samba

Raspberry Pi 4 introduced improved throughput on the Ethernet port, taking it up to full-fat Gigabit speeds. So it’s perhaps no surprise that building a super-fast NAS (network attached storage) drive was top of the wish-list for many a Raspberry Pi owner.

Given the popularity of NAS, it’s little surprise to see How to set up Samba also take a top spot on our yearly tutorial list. It’s easy to use a Raspberry Pi as a Samba file server where you can store backups and share files from all the other computers on your network.

SSH and VNC

SSH (also known as ‘Secure Shell’) is an encrypted networking technology that enables you to manage computers from the command line over a network. It’s a technology that many users are unfamiliar with, until they get a Raspberry Pi and want to get into it from another computer on their network. Our How to setup SSH tutorial gets newbies up and running.

While SSH is from the command line, VNC enables you to access your Raspberry Pi desktop remotely. Our VNC: Remote access a Raspberry Pi tutorial was another big-hitter in 2019.

How to build a Carputer (car computer)

And now we’re into the biggest project of 2019. How to build a Carputer (car computer) with your Raspberry Pi and touchscreen. Raspberry Pi makes a fantastic car computer, thanks to its small footprint and fast processing power: it’s better than many computers found in commercial cars.

Build a Raspberry Pi cluster computer

Cluster computing is one of the most modern programming techniques around. There’s strength in numbers and some of the world’s most powerful computers are built of hundreds, in not thousands, of inexpensive systems.

PJ Evan’s Build a Raspberry Pi cluster computer tutorial shows you how to link up four Raspberry Pi boards to build a powerful cluster. This can be used to create a more powerful server (such as the one running this website) or used to learn cluster computing programming techniques.

Cluster computing is a reasonably niche activity, but our readers are a pretty clever bunch so we’re going to hope many of them find a use for this.

The Interactive tabletop RPG table

Plunder dungeons and slay dragons in digital style with this simple TV conversion project for all your role-playing game needs. The MagPi magazine’s very own Rob Zwetsloot built this touchscreen RPG companion device, and it turns out a lot of readers want to build one too.

Steam Link on Raspberry Pi

Gamers rejoiced when Steam released Steam Link. This software enables you to turn a Raspberry Pi into a streaming console, enabling you to play PC games remotely. The games run on PC, and are typically streamed to a Raspberry Pi sitting underneath a television. Our Steam Link tutorial shows you how to set up Steam Link on a Raspberry Pi 4.

Code Pac-Man in Python

It’s one of the most famous games ever made, and Pac-Man in Python is a great learning tool. It’s no surprise that many gamers want to recreate games in Python and our sister magazine, Wireframe recently released a whole book – Code the Classics – dedicated to just that.

<img src="https://www.blogdot.tv/wp-content/uploads/2020/01/the-biggest-raspberry-pi-projects-of-2019-4.jpg" alt="

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ANPR: Car Spy Raspberry Pi

Automatic number plate recognition is used by the police to match cars against a huge database. We don’t have that database, but OpenCV can be used to detect car number plates and detect your own car. It wasn’t long ago that ANPR technology was extremely expensive to purchase, and Raspberry Pi makes it available to everybody. And our ANPR: Car Spy Raspberry Pi project certainly seems to have sparked some interest.

<img src="https://www.blogdot.tv/wp-content/uploads/2020/01/the-biggest-raspberry-pi-projects-of-2019-5.jpg" alt="

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Build a Raspberry Pi telephone exchange

Transform your humble home phone line into a feature-packed PBX (private telephone exchange) with Raspberry Pi and Asterisk. Many readers might just want to experiment with telephone exchange technology at home, but there’s a good business case for learning how to do this: professional PBX systems cost thousands of pounds.

<img src="https://www.blogdot.tv/wp-content/uploads/2020/01/the-biggest-raspberry-pi-projects-of-2019-6.jpg" alt="

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The ZX Spectrum Next

ZX Spectrum Next has been in development for quite some time, but has only been on our website for a few weeks. In that time it’s become one of the biggest stories of the year. David Crookes investigated the development of the ZX Spectrum Next computer with a FPGA (field programmable gate array) using Raspberry Pi Zero as an extender to act as a virtual tape drive, sound interface and 3D graphics enhancer.