Custom PC, Issue 147

Custom PC Issue 147This month’s Hobby Tech column kicks off with a two-page head-to-head review of rival starter kits for those interested in having a crack at e-textiles technology: the Adafruit Gemma Starter Kit and the Kitronik Electro-Fashion Deluxe E-Textiles Pack, both courtesy CPC.

The field of e-textiles, or soft circuits, is driven by one invention: conductive thread. There are various ways of making thread that can conduct electricity, and the two companies featured in my review have opted for different methods: Adafruit weaves thread directly out of stainless steel, which produces a thin yet strong thread; Kitronik takes traditional thread and coats it in a layer of silver before weaving it into a thicker denier which is softer and more flexible than Adafruit’s version. Either way, the result is the same: a thread you can sew, by hand or machine, and which conducts electricity to any electronic components your heart desires – up to a power draw of a handful of micro-amps, of course.

The two kits both look to introduce the user to e-textiles, and there’s a shared approach which concentrates on that most traditional of hardware Hello, World projects, making LEDs light up. The lower-cost Kitronik kit focuses on dumb switches, although some bundled full-size LEDs have built-in blinking circuitry for a modicum of intelligence; the more expensive Adafruit kit, meanwhile, includes the company’s Arduino-compatible Gemma wearable microcontroller, giving it considerably more flexibility. It also includes needles, a strange omission from the otherwise ready-to-go kit put together by Kitronik. As to which came out on top, you’ll just have to read the review to find out.

Another two pages of this month’s column are spent on my report from Manchester MakeFest, unrelated to the recent Liverpool MakeFest, and my personal highlights from the Museum of Science and Industry’s first home-brew maker-centric event. These included Bare Conductive Touch Board powered signing bowls used in the education of special needs pupils, a teletype clattering out ASCII art from a paper tape courtesy the¬†Manchester Vintage and Retro Computing Enthusiasts group, and the wonderful blend of analogue and digital that is the B0rkestra project. There’s plenty more I couldn’t fit into the wordcount, with more coverage of the event available on the oomlout blog for the curious.

Finally, I had the opportunity to talk to Ben Gray about his MeArm project. Reviewed in an early form back in Issue 133, the MeArm is a low-cost hobbyist robot arm built from a single piece of laser-cut acrylic and released under an open hardware licence. Since my original review, Ben has closed down his hobbyist supply company Phenoptix in order to concentrate on MeArm full time, and it shows – the new design is a considerable improvement, and now comes with optional joypad attachment and even a dedicated microcontroller option. Ben’s promised to send across a review sample of the new and improved MeArm as soon as he’s able, so expect to see it covered more fully in a future issue.

All this, plus other interesting things written by people who aren’t me, can be yours with a trip to your local newsagent, supermarket, or from the comfort of wherever you’re reading this from via Zinio and similar digital distribution services.

Custom PC, Issue 133

Custom PC Issue 133This month’s Hobby Tech is an absolute giant: seven pages long, owing to a bonus two-page review of the Nvidia Jetson TK1 development board – and many thanks to the guys at Zotac for granting me exclusive access to the UK’s only press sample ahead of its retail launch! The usual five pages are filled with a tutorial on using relays with the Raspberry Pi, an in-depth look at the Phenoptix MeArm, and a tour of the excellent DOSBox software.

The Jetson TK1 is a good place to start. It’s no Raspberry Pi: launching at ¬£199.99 via Maplin – despite a far lower $192 US RRP – the board is designed for developers with big pockets. Despite this, it may actually be worth the cash: it’s by far the fastest single-board computer I’ve ever had on my test bench, with four 2.3GHz Cortex-A15 CPU cores, a fifth ‘Shadow Core’ for background tasks, and 192 Kepler-class graphics processing cores on its sadly actively-cooled chip. There are, however, issues that will trouble hobbyists looking to use the system. Most surprising of these is a lack of OpenCL support, despite the Tegra K1 on which the Jetson TK1 is based supporting it just fine.

From the high-end to the pocket-friendly with the next review: the Phenoptix MeArm. Supplied by Ben Gray, its designer, the MeArm is a kit of laser-cut acrylic parts and a selection of hobby servos for building a desktop robotic arm. Compatible with anything that can drive servos – or even things, like the Raspberry Pi, that can’t, if you add an I2C controller board – the MeArm is a fascinating entry point to hobbyist robotics, and doubly so thanks to its open nature and extremely low cost.

The tutorial this month is an extension to the Twitter-connected doorbell which appeared in Issue 130. Although the original design worked fine, it lacked an audible alert. The solution: using a relay to trigger the original doorbell’s sounder unit, turning my design into a drop-in upgrade for any wired doorbell while also teaching the basics of how relays can extend the capabilities of a microcontroller or microcomputer platform.

Finally, DOSBox. While I’m a big believer in using real-metal hardware for my vintage computing, even I have to admit that sometimes emulators can be extremely handy – and DOSBox is one of the handiest around. More properly termed a simulator, DOSBox allows you to run old MS-DOS software on modern systems – complete with filters that improve the graphics and full network support. Designed primarily for gaming, its compatibility with images created using the KryoFlux – reviewed in Issue 131 – mean it’s perfect for retrieving data from ageing floppy disks, as well as playing Doom the way it should be played!

All this, plus a bunch of other interesting things written by people who aren’t me, can be yours with a trip to your nearest newsagent or supermarket. If you’d prefer not to leave the house, try a digital copy via Zinio or similar services.