Custom PC, Issue 146

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

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.