Thermal Imaging

Custom PC, Issue 225

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Custom PC Issue 225My Hobby Tech column for this month’s Custom PC Magazine takes a look at the IceWhale Tech ZimaBoard, a self-styled “single-board server,” the relatively low-cost yet high-performance DytSpectrumOwl thermal inspection camera, and the Cyntech Raspberry Pi Heatsink Case – the latter an imposing block of hefty plastic and metal.

The ZimaBoard 216, the cheapest model in the ZimaBoard family, is an interestingly-designed single-board computer which arrives ensconced in its own heatsink case. Powered by an Intel Celeron N3450 – a quiet upgrade from the Celeron N3350 originally planned, likely as a result of component shortages – the base model includes 2GB of LPDDR4 memory and 16GB of eMMC storage pre-loaded with a Linux-based operating system dubbed “Casa OS.”

The hardware is well-designed and comes with room for expansion courtesy of USB 3 ports, two gigabit Ethernet ports, two SATA 6Gbps ports, and – unusually – a PCI Express slot to the side. Actually using the slot, sadly, isn’t easy – and there’s a lot of work still to be done in addressing usability and security issues in the custom OS.

The DytSpectrumOwl is another piece of well-designed hardware somewhat hampered by weaker software. Built by Dianyang Tech, the DytSpectrumOwl is built for thermal analysis of PCBs and materials via a surprisingly high-resolution camera module on a neat adjustable stand – functionally equivalent to, though slightly lower resolution than, the FLIR ETS320 I reviewed back in Issue 201.

At less than half the price, though, the DytSpectrumOwl is a tempting alternative to the FLIR model – and it includes a wonderfully useful focus adjustment knob, dramatically increasing its flexibility. Its software, however, is Windows-only and outputs annoyingly non-standard radiometric JPEG images lacking a visible scale.

Finally, Cyntech’s take on a protective and cooling case for the Raspberry Pi family is a surprisingly chunky design built from plastic with an upper metal heatsink. Built from just three parts – plus an optional fourth spacer layer to make room for a fan, for when passive cooling isn’t enough – the case is pleasingly robust and does a perfectly good job of keeping the Raspberry Pi’s processor from throttling during intensive workloads. Its price, though, makes it hard to recommend over third-party alternatives.

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

Custom PC, Issue 201

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Custom PC Issue 201This month’s Hobby Tech column takes a look at the upcoming Mooltipass BLE hardware password dongle, FLIR’s ETS320 thermal camera for electronics testing, and has a word from Eben Upton about the cost-reduced Raspberry Pi 4 Model B 2GB single-board computer.

First, the Mooltipass BLE. I reviewed the Mooltipass Mini – itself a successor to the original, bulkier Mooltipass – back in Issue 168: a compact, metal-encased device, the Mooltipass Mini holds your passwords in encrypted storage accessible only using a smartcard and four-digit hexadecimal PIN. I’ve been using the Mooltipass Mini with great success since its launch, but it’s always a bit of a pain to use with a mobile device – requiring a USB cable and OTG adapter.

The Mooltipass BLE aims to fix that, by integrated a Bluetooth Low Energy radio. While it can still operate in tethered USB mode, the Bluetooth radio plus internal battery give it a newfound freedom – though my experience is as a beta tester, with finalised and fully-functional firmware still under active development before the device goes on open sale.

The FLIR ETS320, by contrast, is a fully-finished piece of hardware. Regular readers will know that I’ve long been an advocate of thermal imaging analysis for revealing the secrets of electronic devices, and the ETS320 is a considerable upgrade from my usual FLIR C2: the 80×60 resolution thermal sensor of the C2 is replaced by an impressive 320×240 version in the ETS320, at the cost of a dramatically reduced maximum focus distance. I’d also like to thank FLIR for its partnership: the ETS320 has become a permanent fixture in my toolkit, and will be used alongside the C2 for thermal analysis in future hardware reviews.

Finally, the Raspberry Pi 4 Model B 2GB. While the board itself isn’t new, its pricing is: Raspberry Pi Trading recently decided, prompted by falling RAM prices, to retire the 1GB model and make the 2GB model the new entry point into the family. “2GB is a much more viable desktop platform than 1GB,” RPT chief executive Eben Upton told me in an interview for the column. “1GB is great for embedded, but for a desktop platform it’s just a little bit too tight. What it means is that we’re now back to having a really viable desktop machine at our signature price point.”

The full column is available now in Custom PC Issue 201 at your local newsagent, supermarket, or for global delivery from the official website.

Custom PC, Issue 199

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Custom PC Issue 199This month’s Hobby Tech column breaks out the thermal camera once again for a look at Pimoroni’s Heatsink Case for the Raspberry Pi 4, discusses the new Code the Classics educational programming book with Eben Upton, and reviews Bitmap Books’ The Art of Point and Click Adventure Games.

Pimoroni’s surprisingly robust case for the Raspberry Pi 4 – and not, thanks to changes made in the ports on the board, for any other model of Raspberry Pi – is something of an anomaly in the company’s stock: it’s not an in-house design, but rather a third party creation placed in Pimoroni packaging. There’s also not that much to it: the case is nothing more than two pieces of aluminium, some screws, and three thermal interface material (TIM) pads – of which, Pimoroni’s instructions inform the buyer, you should only use one.

Aside from mechanical fit and feel, the majority of the testing took place using my in-house thermal throttling benchmark – ten minutes of heavy CPU and GPU workload plus a five-minute cooldown period, tracked over one-second intervals – and via thermal imaging. The latter is an increasingly important tool for this type of review: placing the heatsink under the thermal camera revealed that there was little thermal headroom in the design, meaning it may not be wholly appropriate for extreme environments or overclocking scenarios – despite handling the benchmark well.

Upton’s Code the Classics, meanwhile, is a programming book with a difference: It takes an in-depth look at a series of classic game types and teaches the reader not only how to program their own but what went into the creation of the originals, including interviewing some big names from the industry. It’s half coffee-table, half-educational and wholly clever – and while Eben Upton provided the code, it’s a definite team effort with Sean Tracey, Dan Malone, Alastair Brimble, David Crookes, Andrew Gillet, and Liz Upton all contributing according to their own skills. Impressively, the entire book is also available to download free of charge under a Creative Commons licence.

Finally, The Art of Point and Click Adventure Games is yet another colourful coffee-table tome from Bitmap Books’ Sam Dyer, and one well worth picking up. Reviewed in the since sold-out Collector’s Edition form – packaged in an oversized cardboard housing designed to mimic big-box PC games of yore, complete with a USB stick disguised as a somewhat shrunken 3.5″ floppy disk – it makes an excellent companion piece to The CRPG Book from the same publisher, and is up to Bitmap’s usual excellent quality.

Custom PC Issue 199 is available now from all good supermarkets and newsagents, via several digital distribution platforms, or for online purchase with global delivery from the Raspberry Pi Press store.

The MagPi, Issue 90

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The MagPi Issue 90This month’s MagPi, the official magazine of the Raspberry Pi Foundation, comes with a surprise bonus: a cover-mounted stand, available to download for 3D printing or laser cutting in the digital version, designed to hold up to three Raspberry Pi 4s in a vertical orientation. Naturally, it needed testing – and so you’ll find a feature comparing the stand to five commercial cases also designed to improve cooling.

My thermal testing feature in Issue 88 proved that putting the Raspberry Pi on its edge, rather than flat on a desk, could improve cooling and allow it to run faster for longer. The same test workload is repeated here on the bundled vertical stand plus cases from FLIRC, Argon40, Pimoroni, The Pi Hut, and SensorEq – and many thanks to all involved for their assistance with review samples.

Each case is installed as per the manufacturer’s instructions, then the Raspberry Pi 4 Model B 4GB inside is given a ten-minute run of a very thermally-intensive workload – an unlocked glxgears to put load on the GPU and a four-thread stress-ng FFT run for the CPU – followed by five minutes cooling. The temperature of each is graphed along with the operating speed of the CPU – which drops as the temperature rises above 80 degrees Celsius.

Finally, each case was placed underneath a thermal camera to see how effective it is at distributing the heat from the SoC. With the notable exception of one case – the case from The Pi Hut, which is constructed from light-transparent but thermally-opaque Perspex acrylic – the imagery helps to indicate whether a design has thermal headroom for longer workloads or is already working as hard as it can.

The feature is available in full in The MagPi Issue 90, which can be purchased in print from newsagents and supermarkets now or with global delivery from the Raspberry Pi Press store. It’s also available for free download under a Creative Commons licence; while the digital version doesn’t include the cover-mounted stand for obvious reasons, the design can be downloaded for home or commercial 3D printing or laser cutting from the magazine’s GitHub repository.

Custom PC, Issue 194

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Custom PC Issue 194My regular Hobby Tech feature provided two opportunities to break out the thermal camera, thanks to a detailed analysis of a range of cooling products for the Raspberry Pi 4 and a review of the Libre Computer Project’s La Frite single-board computer – and there was even time to take a look at Brian Dear’s exhaustive title The Friendly Orange Glow: The Untold Story of the Rise of Cyberculture.

First, La Frite. Funded, as with all Libre Computer Project boards, via crowdfunding, the compact single-board computer is designed to compete with the like of the Raspberry Pi. It certainly has its selling points: there’s a mounting point on the underside for an eMMC storage module, though it uses proprietary mounting holes; there’s a clever midship-mounted Ethernet port to reduce the overall height; and it even comes with the option of a clever two-piece aluminium case that doubles as a heatsink. Sadly, the board’s performance isn’t there, its software support struggles, and despite the name of the organisation its openness is limited to targeting mainstream Linux kernels; the board itself is a proprietary design.

Moving on to the topic of the Raspberry Pi 4, there’s no secret now that the new high-performance processor at its heart runs a little warm. For my analysis of the issue and a look at some potential solutions, a benchmarking workload was executed while temperature and clockspeed were measured and charted – demonstrating handily the loss of performance you get when the system-on-chip begins to heat up.

These data are joined by the same workload while the Raspberry Pi 4 is enjoying the benefits of a range of third-party cooling products: the Pimoroni Heatsink and Fan Shim options, the former running in passive-only and fan-assisted modes and the latter in always-on and software-controlled modes, along with the 52Pi Ice Tower heatsink and fan assembly as supplied by Seeed Studio and running in 5V, 3V3, and wholly passive modes. The temperatures across the run are then charted, while thermal imagery provides a visual insight into how the whole board heats under passive and active cooling.

Finally, The Friendly Orange Glow is a book I’d heartily recommend to anyone interested in the history of a surprising range of modern technologies – from flat-panel plasma displays and multiplayer gaming to Microsoft’s FreeCell. Charting the rise and fall of PLATO, a computer-assisted learning platform now largely forgotten by history, the book is about more than just technology: as its subtitle, The Untold History of the Rise of Cyberculture, suggests, PLATO and those who built and used it were responsible for cultural movements that wouldn’t be repeated elsewhere in the world for decades.

You can pick up the latest issue of Custom PC Magazine at your nearest newsagent, supermarket, or online at the Raspberry Pi Press Store, or grab it in digital form via the usual distribution services.

Benchmarking the Raspberry Pi 3 Model A+

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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.

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Custom PC, Issue 154

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Custom PC Issue 154In this month’s Hobby Tech column I take a good long look at the BBC micro:bit, CubieTech’s latest Cubietruck Plus (Cubieboard 5) single-board computer, and a pack of Top Trumps-inspired playing cards based on vintage computers.

Beginning with the micro:bit, I was lucky enough to be on the receiving end of a press sample when the much-redesigned educational device was finally ready to ship to schools across the UK. Based on the ARM Cortex-M0 microcontroller and boasting integrated Bluetooth Low Energy (BLE), the micro:bit’s main selling point is its excellent support: the web IDE includes four languages suitable for everyone from absolute beginners to experts, there is documentation galore, and the BBC’s TV output includes shows which remind me of the glory days of the BBC Micro and its related programming.

At least, that would be a selling point if the board was actually up for sale. Despite having now mostly fulfilled its promise to ship free micro:bits to all Year Seven pupils in the UK, the BBC has still made no announcement about commercial availability for the educational gadget. Those whose appetites are whetted by the review, then, are best off looking at the CodeBug on which the micro:bit was based, or the new Genuino/Arduino 101 if Bluetooth LE support is a requirement.

The Cubietruck Plus, meanwhile, is an altogether different beast. Kindly supplied by low-power computing specialist New IT, the board is – as the name suggests – a follow-up to CubieTech’s original Cubietruck. The old dual-core processor is long gone, replaced with an Allwinner H8 octa-core chip that blazed through benchmarks with aplomb – and without hitting the boiling-point temperature highs of the rival Raspberry Pi 3.

Sadly, there’s one piece of information that didn’t make it into the review: shortly after the issue went to press, security researchers discovered a debug vulnerability left in Allwinner’s customised Linux kernel which allows any application on the system to gain root permission. Although affecting only selected operating systems, it’s something to be aware of if you’re in the market for an Allwinner-powered SBC.

Finally, the playing cards. Created by start-up 8bitkick following a successful Kickstarter campaign, the deck is nostalgia in a box. The idea is to bring the Top Trumps concept of collectable, trivia-esque comparison gaming to vintage computing: the cards feature everything from the Acorn Atom to the TI-99/4A, plus a joker in the deck in the form of the Raspberry Pi 2 Model B.

The cards are printed with a very high quality finish, but it’s the source of the images that is of most interest: rather than take the pictures itself, 8bitkick has instead scoured the web for images in the public domain or licensed as Creative Commons. It’s no theft, though: while most Creative Commons licenses allow for even commercial reuse if properly attributed, 8bitkick has promised to upload the full deck design to its website for free download and printing.

All this, plus lots of interesting things by people who aren’t me, is only a short trip to the newsagent’s away – or you can stay exactly where you are and grab a digital copy from Zinio or similar services.

Custom PC, Issue 146

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Custom PC Issue 146This month’s Hobby Tech column begins with a look at a topic that has been close to my heart for a number of years now: thermal imaging, and how it can be applied to the field of hobbyist electronics and technology review. If that weren’t interesting enough, there’s also a review of the Novena open-hardware all-in-one desktop, and a look at a little-known bug-fix applied to Sinclair’s classic ZX81 microcomputer.

For years, I’ve wanted a thermal camera. Recently, the price of cameras has plummeted and I was finally able to justify – just about – the cost of the entry-level Flir C2. While it takes a while to get used to thinking in resolutions of 80×60 – the total resolution of the Flir Lepton thermal imaging module featured in the C2 – I’ve been having no end of fun capturing thermal data on everything from single-board computers to my cat.

In the column, though, I argue for the application of thermal imaging in the hobbyist realm. With smartphone-connected thermal cameras now available in the low-hundreds, and a broken-out Lepton module the equal of the one found in the C2 available for just £160, a thermal imaging sensor is no longer the preserve of well-heeled professionals. I’ve found mine useful for tasks from finding hot-spots on a board design to spotting heatsinks which were not properly mated to the components below.

When I wasn’t playing with the thermal camera, I was playing with the Kosagi Novena. Born from the mind of noted hacker Andrew ‘Bunnie’ Huang, the Novena is remarkable: it’s a truly open computer, with everything from the firmware through to the board designs being published under an open-source licence. Loaned by UK hobbyist electronics shop oomlout, I was sad to give the crowd-funded Novena back – despite an ARM-based processor outclassed by even the cheapest of x86 laptop parts.

Finally, the ZX81. I’ve been clearing out much of my classic computer collection as I shift to a smaller office, and while I had to get rid of my rather rare Sinclair ZX81 I wanted to record its existence for posterity. From the very original production run, this machine boasted the ‘cockroach’ – a bug-fix for a fault in the ROM implemented in hardware, with a hand-soldered board attached to the top of the system’s CPU. It’s a jarring sight, and one that I was privileged to see in person: only a handful of cockroach-model ZX81s, fixed while the company waited for corrected ROM chips to arrive, exist and they’re all externally identical to non-cockroach models.

All this, plus a wide selection of stuff written by people who aren’t me, is available now from your local newsagent, supermarket, or digitally via Zinio and similar services.