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Linux User & Developer, Issue 165

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Linux User & Developer Issue 165For my regular review in Linux User & Developer this month I had the great pleasure to spend time with the BBC’s first serious hardware project since it teamed up with Acorn in the 80s: the BBC micro:bit.

Originally known as the Micro Bit, the micro:bit is a teeny-tiny microcontroller-based educational programming platform based on the CodeBug. Like the CodeBug, the micro:bit uses a 5×5 LED matrix on its front side as its main method of communicating with the outside world; unlike the CodeBug, the micro:bit includes built-in Bluetooth Low Energy support as well as a gyroscope and magnetic compass, along with the two-button input layout the two share.

With the backing of the BBC, and a major funding drive from Barclay’s which has seen a micro:bit promised to ever Year Seven pupil the UK entirely free of charge, it’s no surprise to see that plenty of companies are involved in the project. At launch, the device boasted no fewer than four programming languages – three provided by Microsoft – in its web-based IDE, along with a neat smartphone app built by Samsung allowing for Bluetooth LE-based interaction and even wireless flashing of programs.

Based on the ARM Cortex-M0 microcontroller (and, oddly, a significantly more powerful Cortex-M0+ which is used exclusively to handle the USB Mass Storage implementation, allowing for mbed-style drag-and-drop flashing without the need to install drivers or a toolchain locally) the micro:bit is impressive, as is the wealth of documentation and supporting materials the BBC has compiled. There’s a catch, mind you: so far, the BBC has not announced commercial availability – meaning we have no idea how much the gadget is going to cost people not included in the generous Barclay’s-funded giveaway programme.

For the full low-down, plus a lot more interesting stuff written by people who aren’t me, head to your local magazine outlet or stay where you are and pick up a digital copy via Zinio or similar services.

Linux User & Developer, Issue 164

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Linux User & Developer Issue 164My review for this month’s Linux User & Developer magazine is of a device I’ve been playing with for a while now: the Raspberry Pi 3, the first single-board computer from the Raspberry Pi Foundation to include a 64-bit CPU and integrated radio chip.

Following my cover feature for The MagPi magazine, the Raspberry Pi 3 once again graces a magazine cover – and well it should. The switch from ARM Cortex-A7 to ARM Cortex-A53 processors cores in the new Broadcom BCM2837 system-on-chip (SoC) brings with it a considerable performance boost over the Raspberry Pi 2, which itself left the original single-core Raspberry Pi in the dust.

That’s even before discussing the integrated wireless connectivity. Boasting 2.4GHz Wi-Fi, Bluetooth 4.1, and Bluetooth Low Energy, the Raspberry Pi 3 certainly ticks a lot of boxes on the connectivity front – even if the integrated Ethernet port still communicates with the SoC through a shared single USB channel. Best of all, the board is entirely compatible with accessories and software written for earlier models – going all the way back to the early raft of add-ons for the original Raspberry Pi.

One discovery that cropped up between the MagPi launch feature and this review, though, was heat generation: testing under my thermal camera, published on imgur for the curious, revealed that the Raspberry Pi 3 gets considerably hotter than its predecessors – over 100°C under CPU load. This leads to a couple of issues: potential burns if you poke the chip and thermal throttling which dramatically harms performance if the Pi 3 is installed in a case. Coupled with even harsher throttling – from 1.2GHz to just 600MHz – when used with marginal power supplies or low-quality micro-USB cables, there are caveats aplenty.

For the full low-down, pick up a copy of Linux User & Developer Issue 164 from your nearest supermarket, newsagent, or electronically via services such as Zinio.

The MagPi, Issue 43

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The MagPi Issue 43It’s a special week for the Raspberry Pi Foundation: it’s celebrating its fourth birthday with the launch of the new Raspberry Pi 3. It’s a special day for me, too: the latest MagPi magazine boasts a total of thirteen pages of my content, including the cover splash: a detailed and thorough look at the new model.

Boasting on-board Wi-Fi (a community request since the original model launched four years ago), Bluetooth 4.1, Bluetooth Low Energy, and a faster 64-bit ARMv8 processor, the new Pi 3 is a bit of a beast. My cover feature for the magazine begins with a look at those behind it with a double-page spread featuring interviews with project co-founder Eben Upton and the Foundation’s director of hardware and the man responsible for circuit design James Adams – and a massive thank-you to both for sparing the time to talk to me at one of their busiest ever periods!

The feature then moves on to a look a the board itself, with a hero photo of the board spread across another two pages. Each major feature of the board, from the shiny new 64-bit BCM2837 system-on-chip (SoC) processor to the BCM43438 radio module – which required me to get out the microscope in order to capture its markings – has a call-out with close-up photography and an explanation of how it has changed since the Raspberry Pi 2.

Next up is a benchmark spread, which required me to come up with a detailed suite of tests. After some experimentation, I settled on a selection of classic benchmarks – SysBench CPU in single- and multi-threaded modes, Linpack with and without NEON support, Whetstone, Dhrystone, SysBench memory read and write, Ethernet throughput, Quake III Arena timedemo performance, and power draw at load and idle. As an added bonus, I also came up with a way of measuring general-purpose input-output (GPIO) performance under Python, writing a simple benchmark to toggle a pin on and off as quickly as possible and measuring the speed with a frequency counter connected to the GPIO header.

The next double-page spread looks at helping the reader get started with the new device. I walk readers through modifying an existing Raspbian installation to boot on the Pi 3 by editing config.txt, setting up the Wi-Fi module, enabling true OpenGL acceleration on the graphics processor, and how to write programs to get the best performance on the Pi 3. Sadly, I was unable to explain how to use the Bluetooth 4.1 and Bluetooth Low Energy features, as software support was not available at the time of writing.

The spread then ends with a look at five things you could do with a Pi 3 in order to take advantage of the new features and boosted performance. My work for the magazine continues, though, with a review of the Proster VC99 multimeter and Pimoroni pHAT DAC, before coming to a close with a one-page news piece regarding the production status of the popular Raspberry Pi Zero – helping to explain why it has been so difficult to get hold of and settling concerns that it may be bumped to the back of the production queue now the Pi 3 is out.

All 13 pages of my content, and plenty of other stuff by people who aren’t me, are available from your nearest supermarket or newsagent, or as a free PDF download under a Creative Commons licence from The MagPi’s official website.

Linux User & Developer, Issue 162

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Linux User & Developer Issue 162In addition to my regular four-page news spread, this month’s Linux User & Developer features a review of a maker-oriented computer-on-module (COM): the LeMaker Guitar.

The Guitar comes from the same company that brought us the Banana Pro, but while LeMaker has ditched its fruit-themed product nomenclature it’s still drawing inspiration from the same source: the Guitar the Chinese company’s equivalent to the Raspberry Pi Compute Module, based on the same SODIMM-layout module design and featuring a bundled break-out board to make the device’s features more accessible to hobbyists.

Where it improves on the Compute Module’s design is in its specifications: an Action system-on-chip (SoC) processor proves considerably more capable than the ageing BCM2835 of the Raspberry Pi Compute Module, there’s more RAM, and it even has Wi-Fi connectivity – though this, sadly, is based on a module attached to the break-out board, meaning that it’s not something you’ll have available should you decide to build your own circuit with the Guitar module at its heart.

When I reviewed the device, I was particularly impressed with the performance for the price – especially given that the Compute Module is considerably more expensive than the Guitar. In the time since the review, though, retailers have significantly discounted the Compute Module ahead of the planned launch of a 64-bit, 1.2GHz Compute Module 3 later this year based on the same BCM2837 SoC as the newly-launched Raspberry Pi 3. If you’re not in a rush, in other words, it may be worth seeing how much the Compute Module 3 costs before designing anything around the Guitar.

The full review, along with my four-page news spread, can be found gracing the shelves of your nearest supermarket, newsagent, or as a series of zeroes and ones on digital distribution services including Zinio.

Custom PC, Issue 151

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Custom PC Issue 151In my latest Hobby Tech column for Custom PC, I take a look at the Pi Zero-specific pHAT family of add-on boards from local electronics wizards Pimoroni, review the Guitar computer-on-module from China’s LeMaker, and show readers how to enhance a Raspberry Pi with a simple reset-stroke-power switch.

Firstly, the pHATs. The launch of the Raspberry Pi Zero, reviewed in last month’s Hobby Tech, brought with it the opportunity for Pi experts like Pimoroni to come out with some add-on devices matching the same form factor – which is, unsurprisingly, exactly what the company has done. The result is a family of, at the time of the review, three tiny add-on boards: the Explorer pHAT, Scroll pHAT, and pHAT DAC. Each comes with unpopulated GPIO, giving the user the option of soldering on the bundled female header for the ability to easily remove the device or soldering it directly to a Pi Zero to make an ultra-compact electronic sandwich.

The Explorer pHAT is the most versatile of the bunch, adding 5V outputs, inputs, analogue inputs, and even a pair of motor control channels to the Pi’s otherwise feature-light 3.3V GPIO header. The Scroll pHAT, meanwhile, features some bright white LEDs in a 5×11 matrix and comes with software for scrolling messages. Finally, the pHAT DAC is an ultra-compact digital to analogue converter capable of playing back 192KHz 24-bit audio via a pre-fitted 3.5mm jack or optional pair of RCA jacks. In short: there’s a little something for everyone.

The Guitar is LeMaker’s follow-up device to what was previously known as the Banana Pi – and, like its predecessor, LeMaker is taking design cues from the Raspberry Pi Foundation. This time, it’s made a Compute Module-alike: a small SODIMM-layout computer-on-module which comes bundled with a break-out board to access its various features. Considering the high price of the official Compute Module, I had high hopes for the budget-friendly Guitar – and I’m pleased to say that it mostly didn’t disappoint.

Finally, the reset switch tutorial. A variant of the tutorial I prepared for The MagPi tailored specifically to the Custom PC audience, it walks the reader through adding a simple switch to any Raspberry Pi – but focusing on the new Zero – in order to quickly reset the device in the event of a crash. As an added bonus, it also allows you to power the Pi on from a shut-down state.

All this, plus a bunch of stuff written by people other than me, can be yours in Custom PC Issue 151. Either pick up a physical copy from wherever magazines congregate, or snag it digitally via Zinio or similar distribution services.

The MagPi, Issue 40

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The MagPi Issue 40This month’s MagPi, the official magazine of the Raspberry Pi Foundation, is just a little bit special: it is, to my knowledge, the first magazine ever to include a cover-mounted computer. The release of the magazine today also represents the launch of a brand-new Raspberry Pi model: the Raspberry Pi Zero.

I’ve been lucky enough to have been playing with the Pi Zero for some time, having worked on three of the hardware projects you’ll find between the covers of this extra-special issue. After peeling the Pi Zero from the cover, readers will be shown how to solder general-purpose input/output (GPIO) headers onto its otherwise extremely flat face, connect its serial port to a computer for use as a true random number generator (TRNG), and use it with an existing HAT add-on to act as a mood lamp.

The three projects I created for this issue were chosen from a long, long list. The Pi Zero is an exciting device: it features the same specifications as the Raspberry Pi Model A, but in a brand-new form factor a fraction of the size of the original. Naturally, some features have been cut: just like the Model A there’s no Ethernet chip, but there are also no CSI or DSI connectors and no analogue audio or video ports – though composite video is broken out to a solder pad for the adventurous. The ports that do remain have also been modified: the full-size HDMI port is replaced by a mini-HDMI, and the full-size USB port is a micro-USB port which requires a USB On-The-Go (OTG) adapter before it can be connected to standard USB peripherals.

In doing this, the Foundation has created a device that excites me even more than the full-size models. With a production cost so low that it can be cover-mounted on a high-street magazine, it’s now possible to put a full Linux computer in more project than ever before – and with a simple low-cost USB OTG adapter and a Wi-Fi dongle, it can be networked for a total outlay of well below $10. It is, in short, a game-changer, and I look forward to working on many more Pi Zero-related projects in the near future.

If that wasn’t enough, you’ll also find my review of the Tenma 60W Digital Soldering Station which has been my trusty companion in various projects over the last couple of years. It’s always nice to be able to give a device a good, long-haul test before drawing your conclusions and I’ve certainly put the miles in on the Tenma. As I warn in the review a hobbyist doesn’t strictly need a soldering station, but it does make life easier – and the low cost of this unit, purchased from CPC, makes it easy to recommend for those who fancy an upgrade.

All this, plus more – and, remember the cover-mounted Pi Zero – is available in your nearest WH Smith. The magazine itself is also available as a DRM-free PDF download from the official website, licensed under Creative Commons terms, but obviously you’ll have to buy a Pi Zero separately if you want to follow along with any of my projects.

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.

Linux User & Developer, Issue 156

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Linux User & Developer Issue 156This month’s Linux User & Developer magazine features a review of a rather special device, Bunnie Huang’s Novena, on top of my usual four-page spread of the latest news from the open source world.

When noted hacker Andrew ‘Bunnie’ Huang announced that he was to create an open-hardware and open-software laptop, driven by the increasingly closed nature of off-the-shelf alternatives, I was immediately interested. Sadly, when the Novena project’s crowd-funding campaign went live, the pricing – entirely justified by the small production run planned – meant I couldn’t justify a purchase. Thankfully, I have numerous friends in the open hardware community who could – and one, Aaron Nielsen of local Arduino specialist oomlout, was kind enough to lend me his once it had arrived.

The unit I reviewed was the desktop Novena variant, which lacks the battery and charging hardware of the laptop model. Otherwise, it’s the same: an ARM-based open hardware computer in a smart aluminium chassis, designed to be as hackable as possible. It’s also the only system I’ve ever reviewed that came with a selection of tools and a tube of thread-locking compound – required to assemble the device, which arrives in pieces. Even the screen, a Full HD LCD panel, is separate upon delivery – and the assembly instructions include stern warnings on exactly where not to hold it if you want a working Novena at the end of the process.

The Novena certainly isn’t for everyone. Its performance is good for an ARM-based system, but orders of magnitude slower than an x86 machine for computationally-intensive tasks. To concentrate on performance is missing the point, though: the Novena is billed as the hacker’s playground, with everything from the board design and firmware to the microcontroller that drives the optional battery charger available for a sufficiently knowledgeable user to investigate and modify. Add to that a grid-based hardware prototyping area and clever add-ons, including a software defined radio module based on the Myriad-RF 1 from client Lime Microsystems, and you’ve got a seriously tempting device.

The full review, plus my regular news spread, can be read now by visiting your nearest newsagent, supermarket, or by staying where you are and picking up a digital copy via Zinio or similar service.

Linux User & Developer, Issue 155

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Linux User & Developer Issue 155This month’s Linux User & Developer magazine, in addition to my usual four-page news spread at the front, includes just one review from my keyboard: the LeMaker Banana Pro single-board computer.

The story of China’s Banana-themed SBCs is one of intrigue, and bears a brief recap. The family started with the Banana Pi, a functional clone of the popular Raspberry Pi with enhanced specifications. Retaining the overall layout of the original Model B, the Banana Pi included a more powerful dual-core AllWinner A20 processor and an on-board SATA port, along with a few less explicable extras like a built-in microphone.

Sales in China were fair, but it’s the ecosystem which is of interest: various models of Banana Pi-based SBCs have been released, thanks to its open-hardware nature, including units that double as wireless routers or even network switches.

The Banana Pro is a direct replacement for the Banana Pi, designed by LeMaker. While keeping most of the specifications – the AllWinner A20 chip, 1GB of RAM, a gigabit Ethernet port – the board has received an overhaul, boasting a more streamlined design which borrows from both the Raspberry Pi Model B and Model B Plus. As a result, you’ll find an extended GPIO header – finished in fetching yellow – and the removal of the dedicated composite video output jack, but only two USB ports – plus the USB OTG port.

When the Banana Pi launched, it offered more power and wider compatibility than the Raspberry Pi it aimed to emulate; with the launch of the quad-core Raspberry Pi 2, however, the two leapfrogged once more. Keeping the dual-core A20 may have been a mistake, as for roughly the same price the official Raspberry Pi 2 offers far more performance – but, that said, real USB ports and SATA connectivity, along with gigabit Ethernet, are features not to be sniffed at.

If you want to read my full conclusion, along with my four-page spread of the latest news from the world of Linux, open hardware and open source, pick up your copy of Linux User & Developer Issue 155 from your nearest newsagent or supermarket now, or get it from the comfort of your own home electronically via Zinio and similar distribution services.

Custom PC, Issue 144

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Custom PC Issue 144In this month’s Hobby Tech column, I report from the Halifax Mini Maker Faire, build a 4tronix Agobo robot, and take a look at the Acorn x86 Card – a device that let Acorn users try out the joys of Microsoft’s Windows 95.

First, the robot. Designed as a lower-cost and simpler alternative to the Pi2Go-Lite robot I reviewed back in Issue 135, the Agobo is one of the few kits out there designed specifically for the Raspberry Pi Model A+. While that means that you miss out on a few niceties, few of these – like the wired Ethernet port – are all that important to a portable robot build. The advantages outweigh the negatives, too: the Model A+ draws less power, is smaller, lighter, and costs less; the only real shame is that there is no quad-core Raspberry Pi Model A yet available, leaving users stuck with the outdated single-core BCM2835 system-on-chip processor.

As with the Pi2Go-Lite, I enjoyed building the Agobo – a process which was a lot simpler, involving zero soldering and only a little bit of swearing as I tried to get the bearings in the front caster to cooperate – and programming it was a cinch thanks to 4tronix’s great samples. While it’s undeniably more limited than the Pi2Go-Lite or its full-fat Pi2Go brother, the Agobo could well be a good choice for beginners or the budget-conscious – but for a full conclusion, you’ll have to read the review.

I spent two days this month covering the Halifax Mini Maker Faire, with travel expenses very kindly covered by my client oomlout – for whom I’ve been doing regular blog posts – and it was, as these events always are, an absolute pleasure. Housed at Eureka, the national children’s museum, the event – a community-driven spin-off from Make’s Maker Faires – was well-attended, including by numerous guests who had never been to maker-themed events before. There were soldering workshops, hackspaces, a chap who builds automata out of toys, all kinds of wondrous things – and you can read about them in detail this month.

Finally, the Acorn x86 Card. I wasn’t planning to write about it, but I happened to find it while clearing out the office and thought it would be of interest to readers. A relic of the days before x86 compatibility was the norm in personal computers, the add-in card allowed Acorn’s ARM-based Risc PC to run Windows – even Windows 95, at the time the cutting-edge in operating systems. My particular example is a second-generation card featuring a Texas Instruments 486 processor, and I still haven’t got around to fitting it into my Risc PC despite having received it a couple of years ago…

All this, plus a selection of interesting things written by people who aren’t me, is available in Custom PC Issue 144 from your nearest newsagent, supermarket, or digitally via Zinio and similar services.