Author: Jenny List

3314 Articles

The Micro:Bit Gets A Foundation

October 19, 2016 by 32 Comments

It has been announced that the BBC are to pass their micro:bit educational microcontroller board on to a non-profit-making foundation which will aim to take the project to a global audience. The little ARM-based board with its range of simple on-board peripherals and easy-to-use IDEs was given to every British 13-year-old earlier this year with the aim of introducing them to coding at an early age and recapturing some of the boost that 8-bit BASIC-programmable computers gave the youngsters of the 1980s.

Among the plans for the platform are its localization into European languages, as well as a hardware upgrade and an expansion into the USA and China. Most excitingly from our perspective, the platform will henceforth be open-source, offering the chance of micro:bits finding their way into other projects. To that end thay have placed a reference design in a GitHub repository.

We’ve covered the micro:bit story from the start here at Hackaday, from its launch to the point at which it shipped several months late after a few deadlines had slipped. We reviewed it back in June, and found it a capable enough platform for the job it was designed to do.

This is an interesting step for the little ARM board, and one that should take it from being a slightly odd niche product in one small country to the global mainstream. We can’t help however thinking that price is it’s Achilies’ heel. When it costs somewhere close to £13 in the UK, it starts to look expensive when compared to the far more capable Raspberry Pi Zero at £5 or a Chinese Arduino clone at about £2.50. Here’s hoping that economies of scale will bring it to a lower price point.

A Win For The Raspberry Pi Compute Module

October 19, 2016 by 40 Comments

News comes from the Raspberry Pi Foundation, of something of a coup for their Compute Module product. Support for it is to be integrated into NEC’s line of commercial displays, and the electronics giant has lined up a list of software partners to provide integrated signage solutions for the platform.

It is interesting to note how NEC have done this, while it’s being spun by the Foundation as a coup for them the compute module sits on a daughter board in a slot on the back of the display rather than on the display PCB itself. They are likely hedging their bets with this move, future daughter boards could be created to provide support for other platforms should the Compute Module board fail to gain traction.

Given that this relates to a high-end commercial product from just one manufacturer, what’s in it for us in the hardware community? After all, it’s not as if you’ll be seeing Compute Module slots in the back of domestic TVs or monitors from NEC or any other manufacturer in the near future. The answer is that such a high-profile customer lends the module platform a commercial credibility that it may not yet have achieved.  Until now, it has found a home mainly in more niche or boutique products, this appearance in something from a global manufacturer takes it to a new level. And as the module finds its way into more devices the chances of them coming within the reach of our community and providing us with opportunities for adapting them for our purposes through the Pi platform become ever greater.

The use of the Compute Module in displays made for public signage is oddly a continuation of an unseen tradition for ARM-based machines from Cambridge. Aside from British schools a significant market for the Acorn Archimedes platform that spawned ARM was the embedded signage market, and even today there are still plenty of signs concealing RiscOS machines out there in the wild.

We covered the launch of the Compute Module in 2014, but it’s fair to say it’s not appeared much since in the world of Raspberry Pi projects from hardware hackers. This is not because it’s not a good platform; more likely that the Raspberry Pi models A, B, and particularly the Zero are so much cheaper when you consider the significant cost of the Compute Module development board. At the Raspberry Pi 4th birthday party earlier this year, while covering the event as your Hackaday scribe but also wearing my metaphorical Pi kit supplier and Pi Jam organizer hats I stood up in the Q&A session and asked the Foundation CEO Phil Colligan to consider a hardware developer program for the platform. Perhaps a cut-down Compute Module developer board would be an asset to such a program, as well as driving more adoption of that particular board.

The BITX Transceiver Comes Of Age

October 18, 2016 by 28 Comments

There was a time when the idea of building your own single-sideband transceiver was too daunting for all but the most hardcore of amateur radio constructors. After all the process of creating SSB is complex enough in itself without adding the extra complexity of a receiver and the associated switching circuitry.

In 2003 an Indian radio amateur, [Ashhar Farhan], [VU2ESE] changed all that. His BitX SSB transceiver used a bidirectional amplifier design and readily available components such that it could be built by almost anyone using dead bug construction techniques for an extremely reasonable price.

Over the years since [Ashhar] first published his circuit, his design has been taken and enhanced, been presented in kit form, and extended to other bands by multiple other radio amateurs. Until now though it seems as though he himself has taken very little advantage of his work.

It is therefore with great interest that we note a new 40-meter BitX transceiver on the market from a company founded by the man himself. The transceiver itself is an Indian-assembled PCB with an updated circuit using a 12 MHz IF, varicap tuning, and large surface-mount components for easy modification. Just as with the original circuit, there is a full technical run-down of its operation should you wish to build one yourself. For a rather impressive $45 though you might wish to put down the soldering iron, it looks very much worth the wait for international postage.

We don’t often feature commercial product launches here on Hackaday, though we are besieged by people trying to persuade us to do so. So why this one? When the creator of a design that has been as significant as the BitX has been to its community of builders releases a new version it is newsworthy in itself, and if they are commercializing their work then they deserve that reward.

We’ve featured the BitX here in the past, with a rather impressive dead-bug build, and a look at a multiband version. We’re sure that this design thread has more to deliver, and look forward to more.

Thanks [WB9FLW] for the tip.

A Robot Arm From The Cupboard

October 16, 2016 by 4 Comments

Building a simple robot arm is a lot more straightforward than it used to be.  If you have a laser cutter, or a bit of cash and don’t mind waiting for postage, there are inexpensive kits like the MeArm. If you have a 3D printer, there are any number of 3D-printed designs for you to tackle. What if you need to satisfy your urge to build a robot arm really quickly, and you don’t have a laser cutter or 3D printer? You’ve got a pile of servos from that remote-control project, how can you make the rest?

If you are [roboteurs], you raid the stationery cupboard, and create an arm using rubber bands, paper clips, and binder clips. The binder clips grip the servo arms and hold the whole thing together, the rubber bands provide extra attachment , and the paper clips are bent to form the jaws. It’s not the prettiest or perhaps the most capable of arms, but it undeniably is an arm, and we’d doubt it could be done any more cheaply.

In this particular case, the arm serves as a demonstration piece for [roboteurs]’ Printabots Maker Kit for people without a 3D printer. It uses their controller board, but there is no reason why it could not be used with any other board capable of driving servos.

We’ve covered innumerable robot arms over the years, This one may be the cheapest, but another contender might be this cardboard arm. None of them, however, are as cool as this steam-powered Armatron toy.

Estimate Your English Vocabulary Using Python

October 16, 2016 by 11 Comments

We take our mother tongue for granted, a language we learn as young children without realizing the effort involved. It is only when as adults we try to pick up another language that we fully understand how much hard work surrounds each acquired word.

Depending on who you listen to, estimates vary as to the size of a typical native English speaker’s vocabulary. The ballpark figures seem to put most adults under 20 thousand words, while graduates achieve somewhere around 23 thousand words. It’s a subject [Alex Eames] became interested in after reading a BBC article on it, and he decided to write his own software to produce a personal estimate.

His Python script takes the Scrabble word list, and presents the user with a list of words, for each one of which they have to indicate their comprehension. After a hundred words have been presented it calculates an estimate of the size of the user’s vocabulary. [Alex] wrote it on and for the Raspberry Pi, but it should work quite happily on any platform with Python 3. It certainly had no problem with our Ubuntu-based PC.

There is plenty of opportunity for bragging over the size of one’s vocabulary with a script like this one, but it’s something of a statistical leveler in that if you are truthful in your responses it will almost certainly put you exactly where you might expect for your age or level of education. If you want to know the result this script returned for a Hackaday scribe, for example, the answer is 23554.

This subject is a slight departure into software from our usual hardware subject matter, but it’s one of those tests that becomes rather a consuming interest when performed competitively among a group of friends. How well will you fare?

Via [Recantha]

Finding A Use For Surplus Filament Spools

October 16, 2016 by 19 Comments

If you’re a heavy user of a 3D printer, or a welder, you’ll know the problem of empty spools. You’ve used up all the filament or the welding wire, and you’re left with a substantial plastic spool. It’s got to be useful for something, you think, and thus it’s Too Good To Throw Away. Before you know it you have a huge pile of the things all looking for a use that you know one day you’ll find.

If you follow the example of [Chuck Hellebuyck], you could use them as wheels for a small go-kart (YouTube link). He 3D-printed some hub adapters for the spools to use skate bearings, mounted them of threaded axles to a classic wooden go-kart frame, and set off downhill wearing his stock-car racing helmet.

Of course, [Chuck]’s go-kart is a bit of fun, but it’s probably fair to say that 3D printer spools are not the ideal wheel. Those rims aren’t particularly durable, and with no tires he’s in for a bumpy ride. Perhaps a tire could be found to fit and a tube placed within it, but that would start to sound expensive against those cheap off-the-shelf wheelbarrow items.

But the project does raise the interesting question: what exactly do you do with your empty spools? There have to be some awesome uses for them, so please share yours in the comments. Meanwhile follow Chuck’s go-kart adventures in the video below the break.

Continue reading “Finding A Use For Surplus Filament Spools” →

A Lot Of WiFi Power, A Yagi, And A Sniper’s ‘Scope

October 15, 2016 by 52 Comments

Do you remember the early days of consumer wireless networking, a time of open access points with default SSIDs, manufacturer default passwords, Pringle can antennas, and wardriving? Fortunately out-of-the-box device security has moved on in the last couple of decades, but there was a time when most WiFi networks were an open book to any passer-by with a WiFi-equipped laptop or PDA.

The more sophisticated wardrivers used directional antennas, the simplest of which was the abovementioned Pringle can, in which the snack container was repurposed as a resonant horn antenna with a single radiator mounted on an N socket poking through its side. If you were more sophisticated you might have used a Yagi array (a higher-frequency version of the antenna you would use to receive TV signals). But these were high-precision items that were expensive, or rather tricky to build if you made one yourself.

In recent years the price of commercial WiFi Yagi arrays has dropped, and they have become a common sight used for stretching WiFi range. [TacticalNinja] has other ideas, and has used a particularly long one paired with a high-power WiFi card and amplifier as a wardriver’s kit par excellence, complete with a sniper’s ‘scope for aiming.

The antenna was a cheap Chinese item, which arrived with very poor performance indeed. It turned out that its driven element was misaligned and shorted by a too-long screw, and its cable was rather long with a suspect balun. Modifying it for element alignment and a balun-less short feeder improved its performance no end. He quotes the figures for his set-up as 4000mW of RF output power into a 25dBi Yagi, or 61dBm effective radiated power. This equates to the definitely-illegal equivalent of an over 1250W point source, which sounds very impressive but somehow we doubt that the quoted figures will be achieved in reality. Claimed manufacturer antenna gain figures are rarely trustworthy.

This is something of an exercise in how much you can push into a WiFi antenna, and his comparison with a rifle is very apt. Imagine it as the equivalent of an AR-15 modified with every bell and whistle the gun store can sell its owner, it may look impressively tricked-out but does it shoot any better than the stock rifle in the hands of an expert? As any radio amateur will tell you: a contact can only be made if communication can be heard in both directions, and we’re left wondering whether some of that extra power is wasted as even with the Yagi the WiFi receiver will be unlikely to hear the reply from a network responding at great distance using the stock legal antenna and power. Still, it does have an air of wardriver chic about it, and we’re certain it has the potential for a lot of long-distance WiFi fun within its receiving range.

This isn’t the first wardriving rifle we’ve featured, but unlike this one you could probably carry it past a policeman without attracting attention.