What’s all this?

Question MarkThis is a portfolio site for Gareth Halfacree, the former systems administrator to the left – or above, on a mobile device – currently earning a living as a full-time technology journalist and technical author. You may know him from his best-selling books the Raspberry Pi User Guide and the Official BBC micro:bit User Guide, or his contributions to national magazines, radio programmes, and publications including Imagine Publishing’s Genius Guide and Tips, Tricks, Apps & Hacks series – or even his eponymous “Gareth Halfacree’s Hobby Tech” feature, a five-page spread in Dennis Publishing’s Custom PC Magazine each month. Read more

Custom PC, Issue 185

Custom PC Issue 185In my regular Hobby Tech column this month you’ll find a detailed review of the Raspberry Pi 3 Model A+ single-board computer, another of the ever-so-slightly less-powerful Digirule2, and of Adam Fisher’s exhaustive Valley of Genius: The Uncensored History of Silicon Valley.

First, the Raspberry Pi. The first model to use the A+ form factor – smaller PCB, only one USB port, full-size display (DSI), camera (CSI), and HDMI ports, analogue audio-video (AV) – in the last four years, the Pi 3A+ is an impressive beast for cramming the full performance of the larger, more expensive Pi 3B+ into a smaller form factor. I was concerned, upon first unpacking, that the smaller PCB would undo the good work on the thermal-transfer front that made the Pi 3B+ such a good improvement on the original Pi 3B; a quick test under a thermal imaging camera, though, showed that I was worrying over nothing.

The Digirule2 is a markedly different beast. While it’s a single-board computer, it’s one which is designed more for fun than functionality: built into the form factor of a ruler, complete with inches and centimetres marked in binary along the upper and lower edges, the Digirule2 is inspired by classic machines like the Altair 8800. Press a series of buttons to program a particular memory location; press another button to switch to the next; and press a third to see your program run on the built-in LEDs. One particularly impressive feature is an eight-slot program storage, allowing you to save and load your programs directly on the device – and all without having to hook up your punch-tape reader/writer.

Finally, Adam Fisher’s Valley of Genius is a book in the mould of Fire in the Valley: an attempt to document the rise and, frankly, continued rise of Silicon Valley and the companies it has birthed. Culled from over 200 individual interviews, the book uses direct quotation rather than any attempt to weave a narrative but dodges dryness by weaving multiple subjects’ remembrances into each themed chapter. The final effect is less an interview and more a conversation between some of the industry’s biggest names, from the birth of the mouse right through to the modern age.

To read the full column, pick up Custom PC Issue 185 from your nearest newsagent, supermarket, or electronically via Zinio and similar distribution platforms.

The Official Raspberry Pi Beginner’s Guide

The Official Raspberry Pi Beginner's GuideToday sees the release of The Official Raspberry Pi Beginner’s Guide, my latest educational book on the remarkable single-board computer and its software and the first to be made available for free download and redistribution courtesy of a Creative Commons Attribition-ShareAlike-NoCommercial licence.

Written in partnership with Raspberry Pi Press, The Official Raspberry Pi Beginner’s Guide walks newcomers through a tour of the Raspberry Pi and what it can do, setting up both the hardware and the software, learning how to navigate the Raspbian desktop, how to write programs in Scratch 2 and Python 3, and even building custom circuits that use the Raspberry Pi’s general-purpose input-output (GPIO) header. If that weren’t enough, there are chapters on using the Sense HAT add-on board, the Raspberry Pi Camera Module, and a handy list of additional resources for when you’ve finally exhausted the book itself.

While it’s my name on the cover, this book is very much a team effort. I’d like to thank everyone at Raspberry Pi Press who was involved in its creation, from the authors of the original projects pulled in and updated in this new publication to eternally-patient project editor Phil King, fantastic technical editor Simon Long, amazing illustrator Sam Alder, and a whole host of others without whom the book would be nowhere near as good as it has turned out.

The book is available to buy now in all good newsagents, supermarkets, and bookstores, or direct from Raspberry Pi Press. The digital edition, as a Creative Commons-licensed PDF without any digital rights management (DRM) restrictions, is available from The MagPi website now.

The MagPi, Issue 76

The MagPi Issue 76There’s no missing my contribution to this month’s The MagPi: it’s plastered all over the cover. The launch of the Raspberry Pi 3 Model A+ ends a four-year absence of the compact form factor from the Raspberry Pi line-up, and there’s no better way to celebrate its launch than with a massive cover feature.

The spread begins with a two-page introduction dominated by imagery of the board, before moving on to a plan view which calls out the individual components that make up the board – including the single USB port, BCM2387B0 system-on-chip (SoC), and the radio which, for the first time in a Model A variant, adds WiFi networking and Bluetooth connectivity. Each part includes macro photography, all taken in my in-house studio.

The next section of the feature runs through a series of benchmarks which, in-keeping with previous launches I’ve covered, compares the Pi 3A+ with other mainstream Pi models going all the way back to the original Raspberry Pi Model B. The feature also includes a look at the size and weight, the first time I’ve used that particular metric, along with comparative thermal imagery showing how the smaller surface area of the PCB copes with running the same high-performance processor as the larger Pi 3B+ – again, all captured in-house.

Finally, the cover feature closes with a two-way interview I conducted with project co-founder Eben Upton and principal hardware engineer Roger Thornton. In it, Eben confirms that the Pi 3A+ represents “tidying up ‘classic’ Raspberry Pi,” and that the Raspberry Pi 4 – still very much on the drawing board – will launch a whole new era for the low-cost single-board computer family.

The launch issue is available now from your nearest newsagent or supermarket in print, or can be downloaded free of charge under a Creative Commons licence from the official website.

HackSpace Magazine, Issue 13

HackSpace Magazine Issue 13This month’s maker-focused HackSpace Magazine includes my relatively long-term review of an extremely clever, though far from perfect, temperature-controlled soldering ‘station’: the Miniware TS100.

First, some necessary definitions: brushing aside standard, fixed-power soldering irons, you’ll find adjustable-temperature and temperature-controlled irons on the market. The former are, typically, not much larger than a standard soldering iron and include a small knob on the body for adjusting the power and, thus, temperature of the tip. The latter go a step further, reading the temperature of the iron and using the feedback to dynamically adjust the power output to keep the tip as close to a chosen temperature as possible, and most often come with a bulky base station to which the iron is tethered.

The Miniware TS100, and its not-yet-available-in-the-UK successor the TS80, is different. While it’s a fully-fledged temperature-controlled iron, there’s no base station in sight: instead, the iron packs everything it needs into a surprisingly compact body, including a small OLED screen for live feedback and adjustment of its settings.

What’s most interesting about the design, though, is that the firmware that drives its internal microcontroller is open source. It’s entirely possible to download the source code, modify it, and flash it onto the iron with nothing more than a simple USB cable – and many have done that, producing alternative firmwares which either improve its performance or turn it into something else, including a Tetris-playing games console and a functional oscilloscope, entirely.

The TS100 is clever, then, but not perfect. A design which lacks any form of flaring to stop your fingers drifting forward onto the hot tip is one thing, but a larger problem is an ungrounded power design which leaves the tip floating at voltages more than enough to damage sensitive components. Thankfully, the reviewed unit came with a bundled grounding strap – but that leaves you with two wires rather than one, hampering the portability somewhat.

The full review can be read in the print and digital copies of HackSpace Magazine Issue 13, with the latter available for free download now under the Creative Commons licence from the official website.

Benchmarking the Raspberry Pi 3 Model A+

Back in March, the release of the Raspberry Pi 3 Model B+—the Pi 3 B+ to its friends—brought a chance to take stock and review just how far the project had come since its launch via a series of benchmarks. Now the launch of the Raspberry Pi 3 Model A+ brings a bold claim: a dramatic drop in size, weight, and price over the Pi 3 B+, but without any loss in performance.

In other words: it’s benchmark time once again.

Read more

Custom PC, Issue 184

Custom PC Issue 184Hobby Tech this month takes a look at a trio of very different products: the Clockwork GameShell modular hand-held console, the Dexter GiggleBot BBC micro:bit-powered robot, and the Coinkite Coldcard hardware cryptocurrency wallet.

First, the Coldcard. Designed by the company behind the Opendime (reviewed in Issue 175, and dead due to an apparent design flaw a week later), the Coldcard is roughly the size of a small stack of credit cards but provides a full hardware wallet for the Bitcoin and Litecoin cryptocurrencies. At least, that’s the theory: sadly, in practice, the device proved difficult to use owing to software glitches, hardware flaws, and a lack of third-party software support which reduces you to using only one wallet package to interface with the Coldcard.

The GiggleBot, by contrast, is a significantly more polished product. While the documentation still needs work, the robot itself – featured two individually-addressable motors, a line- or light-following sensor board, RGB LEDs, and expansion potential from Grove-compatible connectors and a pair of servo headers – is exceptionally impressive, and a great introduction to basic robotics for younger programmers. Those looking to make the leap from the block-based MakeCode environment to Python, though, will discover that the two libraries are far from equivalent in terms of feature availability – something that, again, will hopefully be addressed in the future.

Finally, the Clockwork GameShell. Produced following a successful crowdfunding campaign, the device is based around a Raspberry Pi-like single-board computer dubbed the Clockwork Pi and runs a customised Linux distribution with neat menu system. Its internals, interestingly, are modular, with each contained inside a snap-together transparent plastic housing – a decision which makes for a slightly bulky Game Boy-like outer shell and, sadly, is the direct cause of some overheating problems for the system-on-chip (SoC) during more intensive games like Quake. These issues, though, are largely outweighed by sheer novelty value: a few minutes of FreeDoom in the palm of your hand is sure to raise a smile.

The full reviews can be read in Custom PC Issue 184, available from your nearest supermarket, newsagent, or digitally via Zinio and similar services.

Custom PC, Issue 183

Custom PC Issue 183In Hobby Tech this month, there’s a look at a project which has genuinely transformed my mornings, a tiny temperature-controlled soldering iron with a hackable firmware, and the latest brain-melting program-’em-up from Zachtronics.

Starting with the game first, Exapunks caught my eye as soon as I saw it announced by developer Zachtronics. Taking the assembler programming concept of earlier titles TIS-100 and Shenzhen-IO, Exapunks wraps them up in a 90s near-future cyberpunk aesthetic alongside a plot driven by a disease called “the phage” which turns victims into non-functional computers. Because of course it does.

Anyone familiar with Zachtronics’ work will know what to expect, but Exapunks really dials things up. From the puzzles themselves – including one inspired by an early scene in the classic film Hackers – to, in a first for the format, the introduction of real though asynchronous multiplayer on top of the standard leaderboard metrics, Exapunks excels from start to oh-so-tricky finish.

The MiniWare TS100 soldering iron, meanwhile, sounds like it could be straight from Exapunks – or, given its name, TS-100: a compact temperature-controlled soldering iron with built-in screen and an open-source firmware you can hack to control everything from default operating temperature to how long before it enters power-saving “sleep mode.” While far from a perfect design – and since supplanted by the TS80, not yet available from UK stockists – the TS100 is an interesting piece of kit, with its biggest flaw being the need to use a grounding strap to avoid a potentially component-destroying floating voltage at the iron’s tip.

Finally, the project: an effort, using only off-the-shelf software tied together in a Bash shell script, to print out a schedule of the days’ tasks on my Dymo LabelWriter thermal printer. Using the code detailed in the magazine, the project pulls together everything from weather forecasts to my ongoing tasks and Google Calendar weekly schedule – along with a word of the day and, just because, a fortune cookie read out by an ASCII-art cow.

All this, and a variety of other topics, is available in the latest Custom PC Magazine on newsagent and supermarket shelves or electronically via Zinio and similar services.

Custom PC, Issue 182

Custom PC Issue 182In my Hobby Tech column this month, I take a look at the disappointing Planet Computers Gemini PDA, the significantly less disappointing Proto-Pic Program-o-Tron, and the recent updates designed to make the Raspbian operating system for the Raspberry Pi significantly more welcoming to newcomers.

First, the Gemini PDA. I’ve long been a fan of the clamshell personal digital assistant (PDA) form factor, and it was with a heavy heart that I finally hung up my Psion Series 5 after it became clear that smartphones had won that particular war. Now, the format is back courtesy of Planet Computers and the crowdfunded Gemini PDA – a design based on the Psion Series 5 and put together by one of the staff responsible for the original, but which misses its mark at almost every turn.

At its heart, the Gemini PDA is an Android smartphone – even the non-4G version, which is simply an Android smartphone with the cellular radio removed. While it’s possible to run a Debian-based Linux on top, the experience is poor – but, that said, no more poor than the buggy Android build supplied with the device, which insists on booting up in German despite being clearly marked as a UK model. The hardware, too, disappoints: performance under Linux is not where it should be, and while the keyboard is a near-perfect match to the original Psion design the clever sliding hinge mechanism is entirely missing in favour of a loose and flimsy metal kickstand that fails to provide nearly enough support.

Many thanks must go to the National Museum of Computing (TNMOC), which kindly provided an original Psion Series 5MX PDA for direct head-to-head comparison during the review.

The Program-o-Tron, after a disappointing start to the month, proved considerably better. Again crowdfunded, the Proto-Pic device is designed to make life easier for those working with Atmel ATmega microcontrollers. Rather than having to program each chip individually from a PC, the Program-o-Tron allows you to hold six hex files on an SD card and flash them onto a chip inserted in the ZIF socket at the push of a button – and, even better, to take a dump of the contents of a chip, including its fuse settings, to clone it without ever needing to touch the original program code.

Finally, the recent update to Raspbian operating system for the Raspberry Pi brought a couple of changes for the better: a lightening of the load when it comes to pre-installed software, complete with a tool to add packages back in on-demand, and a first-run welcome wizard which walks newcomers through configuring the Wi-Fi networking, localisation settings, and choosing a new password. The latter is particularly welcome: since launch, the default for Raspbian has been to keep the ‘pi’ and ‘raspberry’ username and password combination, making it easy for attackers to gain access to systems accidentally or deliberately connected to public networks. By asking users to choose a new password on first boot, the hole is closed.

To read more, pick up Custom PC Issue 182 from your nearest newsagent, supermarket, or digitally via Zinio or similar distribution platforms.

HackSpace Magazine, Issue 10

HackSpace Magazine Issue 10Readers over a certain age will remember the glorious, though brief, age of the personal digital assistant: pocket-size gadgets, typically though not always in clamshell format, exemplified by Psion’s classic Series 5MX. The rise of the smartphone was the death of the PDA, but there’s a company still clinging to the dream: Planet Computers, with its Gemini PDA.

Reviewed in the latest HackSpace Magazine in Gemini 4G form, which adds an LTE radio for data and voice traffic allowing the device to double as a cumbersome smartphone, the Gemini traces its lineage all the way back to the Psion Series 5. Sadly, as a loaner Series 5MX kindly provided by The National Museum of Computing (TNMOC) proved, the resemblance is only skin-deep: the clever sliding keyboard mechanism of Psion’s design is replaced in the Gemini by a straightforward fold supported by a too-weak metal hinge at the back which only loosens over time.

Given HackSpace’s target audience, my review focused less on the device as supplied – running Android 7 – and more on how it acts when given a customised version of Debian Linux supplied for the more technical user by Planet Computers. Installation wasn’t straightforward, sadly, and use even less so – and a battery life test revealed the unoptimised nature of the Debian port, cutting nearly four hours off the device’s lifespan during a video playback test.

I’m still a believer that there’s a demand out there, albeit small, for what would be a true Psion Series 5MX successor: robust, chunky yet pocket-size, with an outdoor-readable display based perhaps based on colour E-Ink technology. Sadly, the Gemini isn’t it.

The full review is available now, both in print and as a free-as-in-speech-and-beer digital download from the official website.

Custom PC, Issue 181

Custom PC Issue 181In this month’s Hobby Tech column I take a look at two LED-adorned educational electronics kits, the Kitronik :GAME ZIP 64 and the Kano Pixel Kit, along with Mark Hardisty’s latest retrogaming project, The Classic Adventurer.

Kitronik’s :GAME ZIP 64, which will henceforth be known as the much easier to both read and type Game Zip 64, is a clever little add-on for the BBC micro:bit educational platform. Designed to mate with the BBC micro:bit’s edge connector, the Game Zip 64 adds 64 individually-addressable RGB LEDs, a major upgrade on the single-colour 25-LED matrix on the BBC micro:bit itself, buttons to form a four-way directional control pad, two fire buttons, a piezoelectric buzzer, and – interestingly – a vibration motor.

While the sample Python programs – Snake and Pong – are pretty poor, Kitronik has produced a series of lesson plans around the device which are absolutely fantastic, and put the £40 asking price well into ‘bargain’ territory for anyone looking to move on from the built-in features of the bare BBC micro:bit itself.

The Kano Pixel Kit is, on the face of it, a similar device: a matrix of 128 LEDs – twice the number of the Game Zip 64 – dominate the front, but control is limited to a function dial and a couple of buttons. It’s also Kano’s first truly standalone product, eschewing the normal Raspberry Pi for an on-board Espressif ESP-WROOM-32 microcontroller. As with the Kano Computer Kit, the Pixel Kit’s software – which, sadly, is not available for mainstream Linux, despite coming in a Raspberry Pi variant – is fantastic, but its development cost is likely behind the eyebrow-raising £75 asking price.

Finally, Mark Hardisty’s latest project – after putting his groundbreaking tome on the history of Gremlin Graphics to bed and recreating some classic artwork in Inlay – is The Classic Adventurer, a magazine dedicated to the glory days of interactive fiction. Available in print and also, all credit to him, as a free-as-in-beer DRM-unencumbered PDF download, each issue is packed with brilliant art and fascinating articles ranging from interviews to reviews with some behind-the-scenes stuff thrown in for good measure. It’s a fantastic project, and definitely one to follow.

All this, plus the usual raft of other people’s work, can be found at your nearest newsagent, supermarket, or electronically via Zinio and similar digital distribution platforms.