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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 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.

The MagPi, Issue 106

The MagPi Issue 106This 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 Pico-powered burglar alarm driven by one or more passive infrared sensors.

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 burglar alarm tutorial builds up step-by-step from introducing a single passive infrared motion sensor to interfacing with multiple sensors, printing status reports over the serial console, and triggering a piezoelectric buzzer in place of a real alarm’s rather louder horn.

As with other tutorials written for the book, full source code – in MicroPython – is provided, along with wiring references designed to make it as easy as possible to add the components to a Raspberry Pi Pico installed on a solderless breadboard. There’s scope for further extension, too: adding break-beam sensors, glass-break sensors, or a code pad for disabling and enabling the alarm on-demand.

The MagPi Issue 106 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 214

Custom PC Issue 214My Hobby Tech feature for Custom PC takes a look at two compact but very different pieces of keyring-compatible open-source hardware, the Solo V2 security key and the FunKey S, and also a colouring book. No, really, a colouring book: the Retro Computer Colouring Book.

The Solo V2 is, as the name suggests, a second-generation follow-up to the original Solo. The core of the project hasn’t changed: it’s an open-source project which aims to create a FIDO/FIDO2-compatible security dongle. Like its proprietary equivalents, the Solo V2 includes both USB and NFC communication capabilities, supports standard protocols, and even has a tamper-proof design with the bulk of the circuit held on a module encased in transparent resin.

Where the Solo V2 splits from its competition is in the firmware. Written in Rust, the biggest change from the original variant, the firmware is entirely open – allowing anyone to not only inspect the code for any reason, from finding security vulnerabilities to ensuring there are no deliberate back doors, but to modify the code in order to add new features.

The FunKey S is, like the Solo V2, designed to hang on your keyring. It’s not a security dongle, though: it’s an entirely functional self-contained games console, running a customised Linux distribution packed with emulators for everything from the Nintendo Game Boy to the Sony PlayStation. Designed to mimic, roughly, the look of the Game Boy Advance SP, the folding console is ridiculously compact – and absolutely everything, from the circuit design to the plastic case, is open source.

Finally, Retro Computer Colouring Book from Quick Web Books sounds like a joke, and it at least partially is: as the bumph on the back of the book makes clear, vintage computers from the 1970s and 1980s were primarily beige or black – and one of the machines included, the Sinclair ZX80, was the same white as the underlying paper. A joke, then, but one which is also usable: machines are represented with custom-drawn line art, and it’s entirely serviceable as a colouring book – and there’s nothing to stop you reimagining machines like the Altair 8800 in a hot pink or lurid purple.

Custom PC Issue 214 is available now at all good supermarkets and newsagents, online with global delivery on the official website, or as a free PDF download without DRM restrictions.

The MagPi, Issue 105

The MagPi Issue 105This month’s The MagPi Magazine includes a six-page tutorial I originally wrote as part of Get Started with MicroPython on Raspberry Pi Pico: The Official Guide, my well-received guide to physical computing on Raspberry Pi’s first-ever microcontroller development board: a two-player reaction-testing game.

As with all projects in the book, the reaction game is designed to build up gradually. The reader is first taken through wiring up a simple circuit with a single LED and a single button, using one to trigger the other. Gradually, the complexity is increased: using the LED to trigger a countdown stopped only when the button is pushed, giving the user a look at how quickly they can react.

The project’s culmination comes with the integration of multiplayer: two buttons are used, and whichever player hits their button first is declared the winner. It’s a simple game, admittedly, but a surprisingly competitive one – and one which introduces a range of core concepts for input handling, timing, and conditional statements.

The MagPi Issue 105 is available at all good supermarkets and newsagents, online with global delivery, or as a Creative Commons-licensed DRM-free no-cost PDF download on the official website.

Custom PC, Issue 213

Custom PC Issue 213In this month’s Hobby Tech column I take a look at how GL shaders can make the video output from emulators – in particular DOSBox – look an awful lot closer to how you remember the same software running on real hardware, review the Argon One M.2 case for the Raspberry Pi 4 family of single-board computers, and take a look at an unusual children’s book: Big Data Girl by Fred Wordie with illustrations by Santiago Taberna.

First, the shaders. Few would argue that the move away from bulky and power-hungry cathode-ray tube displays to modern liquid-crystal displays was a bad thing, except for possibly vintage game enthusiasts. The “pixel art” of old, you see, was never meant to show big, blocky, individual pixels: the CRT would smooth and blend things as a by-product of its relative inaccuracy, meaning when you fire up a classic like Doom or Moraff’s World and feel disappointed in its appearance it’s not entirely down to rose-tinted spectacles.

Shaders, typically but not exclusively written in GL Shader Language, can help. In the opening piece for this month’s column, I look at how these handy add-ons can turn the block output of an emulator into a surprisingly convincing simulation of a CRT – complete with curvature and overscan, if that’s your wont. The difference in appearance is little short of astounding – though it may take some customisation before you’re fully satisfied with the results.

The Argon One M.2, meanwhile, looks externally a lot like the previous entries in the Argon One case family. There’s the same metal shell, which doubles as a heatsink and means the built-in temperature-controlled fan rarely activates, the same magnetic cover hiding a colour-coded and silkscreened general-purpose input/output (GPIO) header, and the same layout which puts all the Raspberry Pi’s various ports to the rear for neater cabling.

Where the new design differs is in a larger base, which hides the circuitry for converting an M.2 SATA SSD into a USB-attached storage device. Unlike the NESPi 4, reviewed back in Issue 210, this one works properly in USB Attached SCSI (UAS) mode, giving a throughput of 387/300MBps read/write on a test SSD rated at 500/320MBps.

Finally, Big Data Girl is a bit of a departure for the column, as it’s a children’s book – but one with a difference: Wordie’s crowdfunded title aims to introduce the concept of “big data,” anthropomorphised as a friendly little girl, highlighting both how useful it can be and how it can impact your privacy. It’s a smart idea, and Taberna’s illustrations are fantastic, but serves more as a conversation starter for parents already familiar with the concepts than a stand-alone guide to the subject.

Custom PC Issue 213 is available now at all good supermarkets, newsagents, digital distribution platforms, and from the official website with international delivery.