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This is a portfolio site for Gareth Halfacree, the former systems administrator 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, The Official Raspberry Pi Beginner’s Guide, Get Started with MicroPython on Raspberry Pi: The Official Raspberry Pi Pico 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 Raspberry Pi Press’ Custom PC Magazine each month.

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Custom PC, Issue 220

Custom PC Issue 220This month’s Hobby Tech dedicates a whopping four pages to one of the most interesting devices I’ve ever had on test: the MNT Research Reform open-hardware laptop. If that weren’t enough, there’s also a look at a classic book of early personal computing history: Ted Nelson’s Computer Lib/Dream Machines.

The meat of my latest five-page column is a relatively straightforward review of the MNT Reform, a laptop that’s anything but straightforward. The brainchild of MNT Research, and the second-generation of the core design, the MNT Reform is open – from the design of the chassis with its eye-catching transparent base to the electrical designs for the motherboard, system-on-module, and even the 3D-printed trackball which sits below a mechanical keyboard.

As a laptop, though, it’s easy to find the Reform wanting on a number of fronts – from lacklustre performance to the absence of niceties like having it suspend when you close the lid. I then dive deeper into the project itself – and reveal something both unique and absolutely worthy of celebration, with an enthusiastic and growing community boding well for its future.

Two of the biggest issues highlighted in the review have since been resolved for future production runs: the trackball has been greatly enhanced by the addition of steel bearings, and the troubling power drain while “off” which can empty the batteries has been addressed with a firmware update to put the system management controller into a low-power deep-sleep mode.

Computer Lib/Dream Machines is, despite having been published in 1974, a publication with a very similar ethos at its heart: the idea that computing not only should be accessible to all but must be accessible to all. Long out of print, despite Microsoft’s efforts to publish a professionally typeset and updated version of the eclectic original in 1987, the book manages to be both of-its-era and yet somehow entirely relevant – and that’s even before you flip Computer Lib over to reveal Dream Machines as a second book bound as one.

The original version of the book has been preserved at The Internet Archive, and is well worth a read – though its format means you may spend quite some time zooming in and out.

All this, and more, is available now at your nearest supermarket or newsagent, online with global delivery, or as a DRM-free PDF download from the official website.

Make: Magazine, Volume 79

Make: Magazine Volume 79This month brings with it my first cover feature for a new client, and it’s one of which I’ve long been a fan: Make: Magazine, the maker-centric electronic hobbyist publication, now in its 79th volume.

For this issue, its biggest of the year, I contributed two features. The first is the biggest: the Boards Guide 2021, the latest version of the magazine’s annual pull-out reference to the latest single-board computers and microcontroller development boards around. It’s an undeniably handy guide, offering everything from key specifications – right down to the number of analogue inputs you’ll find on general-purpose input/output headers, as but one example – to up-to-date pricing, though the latter is rather more variable than usual thanks to continued supply chain issues and component shortages.

Having been provided with a list of the boards to be included, I went through and fact-checked all the specifications – filling in blanks where necessary. At one point, faced with a board for which no dimensions were publicly listed and for which the creator couldn’t be immediately contacted I turned to an unusual approach: estimating its size from a perspective-corrected image of the board, based on the spacing on the 2.54mm header. When I finally obtained official measurements just ahead of deadline, my estimate turned out to be accurate to two significant figures – and I can’t say I wasn’t thrilled!

The second feature, also available on the Make: Magazine website, takes a look at Raspberry Pi’s first in-house microcontroller, the RP2040, and its rapid adoption by third-party board makers. For this, I initially researched a list of nearly 80 RP2040-based devices – pulling in key specifications and features, as with the larger Boards Guide feature – which editor Mike Senese and I then narrowed down to a shortlist to be featured in the magazine and online. Finally, I prepared a brief write-up to accompany the shortlist.

Make: Magazine Volume 79 is available at all good newsagents now, and is available for print and digital subscription on the official website.

Custom PC, Issue 219

Custom PC Issue 219In this month’s Custom PC I take a look at the Airxed IRX Smart Home Hub, revisit the Kobol Helios64 open-spec network attached storage (NAS) appliance, and read through Wired’s pocket-size guide to quantum computing by Amit Katwala.

First, the hub. Looking for all the world like a fat gloss-finish hockey puck, the IRX is effectively a cross between a programmable remote and an environmental monitor. Inside the housing is an array of through-hole infrared LEDs, arranged in a hedgehog-like pattern. Trigger an IR signal using the companion app, and they all fire at once offering room-filling coverage – not like the bad old days of taping an IR blaster to a sensor to get the positioning just right.

Combine that functionality with a temperature and humidity sensor, all drive by an Espressif ESP-12S ESP8266-based microcontroller, and you’ve an interesting device. Sadly, despite an attractive price there are a fair few downsides to the design – and I was entirely unable to find my Yahama AV receiver in the list of infrared gadgets it could control.

I originally reviewed the Helios64, meanwhile, back in Issue 211. At the time my conclusion was that, despite some glaring design flaws and software issues, it was a tempting buy – a conclusion I now revisit on the news that Kobol is closing up shop and the bug-fixed second revision will no longer be released. Couple that with the discovery of yet more hardware failures and serious concerns about the Armbian project on which the device runs, and it’s no longer recommended – even if you could pick one up cheaply on the second-hand market.

Finally, Quantum Computing is the first in a series of compact primers covering a range of topics selected by Wired Magazine. Written by Amit Katwala, it’s a broad though shallow romp through the latest in the field of quantum computing technology – looking at everything from its impact on cryptography to commercial quantum systems. For the curious, it’s a great introduction to the topic – but most will be left wanting something more when they reach the end.

Custom PC Issue 219 is available from all good newsagents and supermarkets, online with global delivery, and as a free PDF download as part of a time-limited offer.

The Official Raspberry Pi Handbook 2022

The Official Raspberry Pi Handbook 2022The latest issue of The Official Raspberry Pi Handbook, an annual aimed at those looking to find out what they can do with their Raspberry Pi, is out now – and in it you’ll find my in-depth coverage of the Raspberry Pi Pico microcontroller board.

Within the special dedicated Raspberry Pi Pico section of the annual is my two-page introduction to the board, an in-depth spread covering its specifications and the various components which make up the hardware – with plenty of high-quality photography, taken in my in-house studio – and an explanation of exactly what a microcontroller is and how the RP2040 at the heart of the Raspberry Pi Pico works.

You’ll also find my guide to programming the Pico in MicroPython and C/C++, an interview with chief operating officer James Adams and senior engineering manager Nick Francis, comment from Eben Upton, a simple hardware “hello, world” tutorial in MicroPython, and a step-by-step guide to safely soldering headers onto the Raspberry Pi Pico’s general-purpose input/output (GPIO) pins.

There’s also a brief overview of my book, Get Started with MicroPython on Raspberry Pi Pico – which, for those who want to explore the topic further, is available as a free PDF download under a Creative Commons licence.

The Official Raspberry Pi Handbook 2022 is available in all good newsagents and bookstores now, online with global delivery, or as a DRM-free download under a permissive Creative Commons licence.

Custom PC, Issue 218

Custom PC Issue 218My Hobby Tech column this month takes a look at the final-release Mooltipass Mini BLE open-source password management gadget, the SQFMI Watchy hacker-friendly smartwatch kit, and Crackers I: The Gold Rush from Microzeit.

I first previewed the Mooltipass Mini BLE back in Issue 201, after gaining access to the pre-release beta. At the time, a lot of the planned features were either only partially functional or entirely absent – though the hardware, at least, was undeniably solid. In the months since, the team has been hard at work and the final Mooltipass Mini BLE is now in backers’ hands.

To say the project has delivered is no understatement. While there are still holes to fill – the lack of any way to save a password onto the device from an Android or iOS smartphone or tablet is a big one – it handles most tasks with ease, and the integration of Bluetooth Low Energy for wire-free connectivity to target gadgets is a game-changer for the user on the go.

The SQFMI Watchy, by contrast, doesn’t quite manage to deliver on its promises. Designed as an open-hardware project centred on an Espressif ESP32 microcontroller and a compact e-paper sunlight-readable display, the electronics are solid enough – but the plastic case is a low point, and the firmware simply isn’t ready.

Despite having Wi-Fi on board, there’s no way to set the time on the Watchy automatically. The default clock face pulls down weather data, which is nice – but it’s pre-set to New York City, and there’s no obvious way to change that. The relevant variable is hidden, it turns out, in files which do not appear in the Arduino IDE when you edit the open-source sketch – and nowhere in the documentation is this mentioned. For anyone willing to spend a lot of time writing their own code based on poor or entirely absent documentation, there’s promise here – but it’s near-unusable out-of-the-box.

Finally, Crackers I. The first in a pair of books covering the rise of computer software piracy – primarily, but not exclusively, games – and the groups on both sides of the fence, Microzeit’s latest is a hefty tome well worth putting on your coffee table. Presented in full colour, the book is thick enough that its image-heavy nature doesn’t annoy – and the stories it tells are fascinating to boot.

Custom PC Issue 218 is available at all good supermarkets and newsagents now, online with global delivery, or as a free PDF download as part of a time-limited offer.

Custom PC, Issue 217

Custom PC Issue 217In this month’s instalment of my five-page Hobby Tech column for Custom PC Magazine, I take a look at the Oratek Tofu carrier board for the Raspberry Pi Compute Module 4 the Zymbit HSM6 hardware security module, and Tim Danton’s The Computers That Made Britain.

The Oratek Tofu is one of a growing number of carrier boards which take a Raspberry Pi Compute Module 4 system-on-module and turn it into a fully-functional compact computer. Designed to break out all the features of the module, there’s only one thing missing: it has no USB 3.0 ports, with Oratek having made the decision to instead break out the PCI Express lanes which would normally connect to a USB 3.0 controller to an M.2 B-key slot for PCIe devices – and an optional adapter board adds support for NVMe storage, too.

Add in a 3D-printed and smartly-designed case, and the Tofu is a tempting proposition – let down only by high pricing. It’s understandable given the small production batch, but if Oratek could find a way to bring the costs down it’d go a long way to making a Tofu plus CM4 a competitor to a Raspberry Pi 4 Model B.

The Zymbit HSM6, meanwhile, is a successor to the HSM4. They’re both ultra-compact hardware security modules, designed primarily for integration into custom designs but available with a carrier board for connection to a Raspberry Pi or Nvidia Jetson for development and experimentation.

The HSM6 offers all the features of the HSM4, plus dedicated support for acting as a hardware cryptocurrency wallet. As with the Tofu, though, the pricing is likely to be an issue – and there’s nothing in the way of user-friendly software available for the device, with users instead being given a smattering of C/C++ and Python sample code and left to experiment.

Finally, The Computers That Made Britain – and a disclosure: I’ve worked with the author Tim Danton, editor of PC Pro Magazine, several times. That has no bearing on my opinion of his book, though: a meticulously researched walk through computers which, while not all were made or even designed in Britain, had an undeniable impact on the country’s coteries of computing enthusiasts and developers.

Building on both original interviews, third-party reportage, and contemporary reports, the book isn’t exhaustive but is definitely enjoyable – and bonus points should be given to a high-quality index, all too often missing from these books, which makes it easily usable for reference once you’ve read it cover-to-cover.

Custom PC Issue 217 is available at all good newsagents and supermarkets now, online with global delivery, or as a free digital download on the official website.

The MagPi, Issue 108

The MagPi Issue 108This month’s issue of The MagPi Magazine includes another of my tutorials for those looking to get started with the MicroPython platform on the Raspberry Pi Pico microcontroller: a data logger, which makes use of the microcontroller’s ability to run saved code away from a computer and its flash file system.

Originally written as part of Get Started with MicroPython on Raspberry Pi Pico: The Official Guide, my guide to physical computing on Raspberry Pi’s first-ever microcontroller development board, this latest tutorial – one of the last in the book – covers file handling in MicroPython, which can often trip up new users: opening a file for writing erases any previous contents, giving you an empty file if you’re not careful.

The tutorial then moves on to reading and formatting temperature data from the on-board sensor, storing it in a file for later loading, and even running the Raspberry Pi Pico without being connected to a Raspberry Pi or other computer – making use of a special file name to load code on boot without user interaction.

The MagPi Issue 108 is available at now at all good newsagents and supermarkets, online with global delivery, or as a Creative Commons-licensed DRM-free zero-cost PDF download on the official website.

Custom PC, Issue 216

Custom PC Issue 216This month’s Hobby Tech column takes a look at the upgraded Arduboy FX Arduino-compatible handheld console, the impressively packed lifetime subscription to 2600 Magazine, and Bolt Industries’ family of PCB reference rulers.

First, the Arduboy FX. Reviewed back in Issue 162, the original Arduboy was a compact credit card-style eight-bit games console designed for use with the Arduino IDE. The idea: to encourage kids to learn programming and write their own games. Its size impressed, but a low-quality screen let it down – as did the inability to load more than one game at a time, severely hurting its portability.

The Arduboy FX fixes one of those two problems, by adding a flash chip which comes loaded with over 200 games and utilities. When switched on, the new Arduboy FX boots into a loader. Pick a game from the loader and it’s flashed automatically, ready for play. It works a treat, but sadly the screen is just as troublesome as before.

2600 Magazine, meanwhile, is a counterculture classic. Launched in 1984 as a newsletter for the established phone phreak and burgeoning computer hacking communities, it’s been running ever since – which makes the offer of a lifetime subscription for just $260, in place since the early days and uncorrected for inflation, a bargain.

It’s a double bargain these days, as your $260 gets you not only every single annual digest of the now-quarterly publication delivered in DRM-free digital form but every issue that has ever been published too. While you’re unlikely to be able to turn the older tutorials into free phone calls any more – at least, unless you find somewhere still running on a crossbar exchange – they provide fascinating glimpses into the history of the culture.

Finally, Bolt Industries’ PCB rules are exactly what they sound like: rulers made out of printed circuit boards. They’re not merely for measuring, however, but provide reference for everything from microcontroller pinouts – including the Raspberry Pi RP2040, on the latest revision – to Ohm’s Law.

All this, and more, can be found on the shelves of your nearest newsagent, supermarket, or online with global delivery – or is available for DRM-free download, free of charge, as part of a time-limited offer.

The MagPi, Issue 107

The MagPi Issue 107This month’s issue of The MagPi Magazine includes another of my tutorials for those looking to get started with the MicroPython platform on the Raspberry Pi Pico microcontroller:a temperature sensor, using the analogue-to-digital converter (ADC) built into the RP2040.

Originally written as part of Get Started with MicroPython on Raspberry Pi Pico: The Official Guide, my guide to physical computing on Raspberry Pi’s first-ever microcontroller development board, the tutorial builds in the same way as the other projects in the book – introducing core concepts then building step-by-step from a minimum-viable project up to a fully-functional completed device.

As with other tutorials written for the book, full source code – in MicroPython – is provided, along with a wiring diagram which shows how to wire up a potentiometer using two or three pins and why that makes a difference to how it works. The project can be attacked with no additional hardware, however: the temperature sensor is built into the RP2040 microcontroller on board the Raspberry Pi Pico, and readers are free to skip building the potentiometer circuit if they don’t have the component lying around.

The MagPi Issue 107 is available at now at all good newsagents and supermarkets, online with global delivery, or as a Creative Commons-licensed DRM-free zero-cost PDF download on the official website.

Custom PC, Issue 215

Custom PC Issue 215My regular Hobby Tech column takes a look at three very different, yet related, items in this month’s Custom PC: the PiStorm accelerator for the Commodore Amiga; the Remodo X Bluetooth remote from Remotec; and Joshua M. Pearce’s Create, Share, and Save Money Using Open-Source Projects.

First, the PiStorm. I’ve long been a fan of Commodore’s ill-fated Amiga family of computers, and while my collection isn’t what it used to be I still have a couple keeping me company around the office. It was in one of these I installed the PiStorm, an open-source accelerator and expansion board designed to be powered by a Raspberry Pi 3 Model A+ – and, in the future, by still-more-powerful models in the Raspberry Pi range.

Donated by my good fried Jaimie Vandenbergh, who had picked up a handful of the low-cost boards for his own use, the PiStorm is nothing short of incredible. Effectively turning the Raspberry Pi into an emulated Motorola processor, it increases an Amiga’s compute performance, memory, graphics capabilities, storage, and even – though not at the time of writing – gives it the ability to connect via a Wi-Fi network. In short: it’s a must-have.

The Remodo X remote, meanwhile, is another accessory aimed at the Raspberry Pi – and a smaller niche. Targeting home automation and home theatre uses, the Remodo X is a surprisingly stylish device with just four buttons on its front and the ability to distinguish between short- and long-press for eight custom-mapped functions.

The device works via both Bluetooth and infrared, though for a gadget Remotec claims is specifically designed for a Raspberry Pi there’s a distinct lack of software: customising its buttons requires a smartphone app, and can’t be done on the Raspberry Pi itself.

Finally, Using Open-Source Projects is a book I wanted to love – after all, I’m a big proponent of free and open-source software and hardware. Sadly, it entirely fails to deliver on its promise – spreading an already-slim book far too thin across far too many topics. Some of the blame lies on the author, but some on the publisher – in particular the poor print quality and bizarre failure to flag the use of a figure which compares an original black-and-white image to its colourised equivalent yet shows both before and after shots in black and white.

The full column, and much more besides, is available in your nearest supermarket or newsagent now, online with global delivery, or – as part of a limited-time offer – as a DRM-free PDF download at zero cost.