Gameduino + Mystorm = Oscilloscope!

August 4, 2018 by Jenny List 4 Comments

There has to be more than one of us who over the years since the launch of systems like the original Game Boy have eyed up these handheld platforms and thought “You could make a really neat little oscilloscope with that!” But the commercial systems are closed-source, locked down, and proprietary, so in many cases there’s little easy prospect of such a device being created.

Fortunately though, there are now very accessible handheld gaming platforms, and [James Bowman], the creator of the Gameduino series of boards, writes in to tell us about an oscilloscope project for the Gameduino 3 created by [Lawrie Griffiths]. It uses a Mystorm FPGA board with an AN108 analogue board, and while the heavy lifting of acquisition is handled by the FPGA it is left to the Mystorm’s STM32 to talk to the Gameduino. There are a few teething troubles such as the Gameduino complaining when it is fed data too quickly, but the result is an effective 8 MHz bandwidth instrument with a touchscreen interface. He does however admit that the interface is a little fiddly at the moment. All the code is available via GitHub, so should you wish to pursue this particular avenue yourself, you can.

The Mystorm has made more than one appearance here over the years, and we’re sure we’ll see more. We saw it emulating a small OLED display to put Arduboy graphics on the big screen, for example, and implementing a complete Acorn BBC Micro home computer.

Finding The Linear In A Laser

August 4, 2018 by Jenny List 12 Comments

If your path has taken you through any work with hi-fi audio, you will be aware of the effects of distortion on sound quality. The tiniest non-linearity in a component can ruin the result, and people who work at the extreme end of the hi-fi spectrum will go to impossible lengths to chase the tiniest percentages of distortion that no human could possibly hear.

[Monta Elkins] has a Boldport kit, the Lite2Sound, which as its name suggests translates a light level to an audio signal. Given a laser diode and a source of country music from his Amazon Echo then, perhaps he could transmit the sound across a beam of laser light. And given that the Lite2Sound is an all-analogue device so unless it incorporates a low-pass filter it might struggle with PWM, to achieve that feat he would have to modulate the country music directly onto the laser light.

In the video below he shows us how he characterised his laser diode by plotting its VI curve on an oscilloscope, and identified its most linear region. He was then able to supply a voltage in the middle of that region, and simply overlay the line level audio from the Echo through an RC network. The result is a successful transmission of music via laser that sounds OK, though we’d find it interesting to see what an audio analyser would make of it. We’d also be interested to know whether the VI curve also maps to the same profile in the light intensity, we suspect the answer would be “close enough”.

So laser wireless audio can be done, and anyone who points out that the same feat could have been achieved with Bluetooth is spoiling the fun. After all, what’s a hi-fi without Frickin’ lasers!

Continue reading “Finding The Linear In A Laser” →

When Is Wrought Iron Not Wrought Iron?

August 3, 2018 by Jenny List 71 Comments

I grew up with a blacksmith for a parent, and thus almost every metalworking processes seems entirely normal to have as part of everyday life throughout my childhood. There seemed to be nothing we owned that couldn’t be either made or repaired with the application of a bit of welded steel. Children of blacksmiths grow up with a set of innate heavy hardware hacker or maker skills that few other young people acquire at that age. You know almost from birth that you should always look away from the arc when dad is welding, and you also probably have a couple of dictionary definitions ready to roll off the tongue.

The first is easy enough, farrier. A farrier makes and fits horseshoes. Some blacksmiths are farriers, many aren’t. Sorry, my dad made architectural ironwork for upmarket houses in London when he wasn’t making improvised toys for me and my sisters, he didn’t shoe horses. Next question.

The second is a bit surprising. Wrought iron. My dad didn’t make wrought iron.

But… Hang on, you say, don’t blacksmiths make wrought iron? At which point the floodgates open if you are talking to a blacksmith, and you receive the Wrought Iron Lecture.

Continue reading “When Is Wrought Iron Not Wrought Iron?” →

Glimmies, As Logic

August 3, 2018 by Jenny List 10 Comments

[Jacob Christ] writes in with a hack that’s going to be this summer’s fidget spinner. Why? The favourite toy of his youngster’s generation is a Glimmie. And while fidget spinners were useful for, well, spinning, the small animal-like Glimmie seems to have an unexpected property, they can function as logic gates.

They form an optical inverter, in their head is a phototransistor and in their belly an LED which goes on when the head is in the dark. He’s found through experimentation that they can be combined to form an AND gate, and thus a NAND gate with the addition of a further inverter. Since all logic functions can be made from NAND gates, it should therefore be possible to go as far as to make any device based upon logic, even up to a fully functional computer. He estimates the cost of a single gate at $16.30. A computer would require in the region of 80,000 Glimmies to work, but maybe someone with deep enough pockets will be foolhardy enough to give it a try.

You can see the AND gate in action below complete with camera work from a youngster, and if unexpected logic gates are something that’s caught your attention you can take a look at the battery booster pack logic we brought you a while back.

Continue reading “Glimmies, As Logic” →

Hackaday Belgrade: Sophi Kravitz’s Blimp Army

August 2, 2018 by Jenny List 12 Comments

Building things that fly is hard. The constraints on small, battery powered, radio-operated gear already presents a challenge, but adding weight, balance, and aerodynamic constraints takes it to a whole new level. Sophi Kravitz rises to the occasion and discusses each challenge of building a blimp from start to finish in her presentation at the 2018 Hackaday Belgrade conference.

One of the pleasures of writing for Hackaday comes through the incredible array of talent and experience to be found among our colleagues. We all do our own work, but one is humbled by that which flows from the benches of those one works alongside. Just such a project is the Remote Control Mini Blimp from our colleague Sophi Kravitz. It’s a game involving an obstacle course and a set of remote-controlled blimps. The challenges in such an endeavour have been pushing the limits of what is possible with off-the-shelf components. Continue reading “Hackaday Belgrade: Sophi Kravitz’s Blimp Army” →

Crowdfunding: !Sinclair !ZX Vega To Lose The Sinclair Name

August 2, 2018 by Jenny List 5 Comments

It’s not a good time to be a backer of the crowdfunded Sinclair ZX Vega retro console. After raising a record sum on Indiegogo, a long series of broken promises and missed dates, and a final loss of patience from the crowdfunding site, it has emerged that the owner of the Sinclair and ZX brands is to withdraw the right to use them from the console.

The Vega itself should have been a reasonable proposition, a slick handheld running the FUSE Spectrum emulator rather than Z80 hardware, and from Retro Computers Limited, a company that boasted a 25% ownership from Sinclair Research and thus Sir Clive himself. The sorry tale of its mishandling will probably in time provide enough information for a fascinating book or documentary in itself, but one thing that has come to light in the BBC’s reporting is the fate of those Sinclair brands. They famously passed to Amstrad in the 1980s, a move that gave us the Spectrum +2 and +3 with decent keyboards and built-in tape and disk drives, but long after the last Spectrum had rolled off the production line they passed with Amstrad’s set-top-box business to the satellite broadcaster Sky, who are now responsible for pulling the plug.

This is a general news story as much as a hardware story as there is little by way of a hack to be found beyond the realisation that you could almost certainly roll your own with a Raspberry Pi, a copy of FUSE, and a 3D-printed case. But it’s a fitting follow-up to our previous reporting, and unless something unexpected happens in the Retro Computers boardroom it’s probably the last we’ll hear of the product. In an unexpected twist though they are reported to have shipped a few Vegas to backers in recent days, and we’ll leave the final word to the BBC’s quote from [David Whitchurch-Bennett], one of those recipients.

“The buttons are absolutely awful, You have to press so hard and they intermittently stop working unless you apply so much pressure.”

From where we’re sitting, remembering the dubious quality of some of the keyboards on original Spectrum products, we think that it might have more in common with the original than anyone is willing to admit.

Are Patent Claims Coming For Your WS2812?

July 31, 2018 by Jenny List 115 Comments

There are some components which are used within our sphere so often as to become ubiquitous, referred to by their part number without the need for a hasty dig through a data sheet to remind oneself just what we are talking about. You can rattle a few of them off, the 555, the 741, the ESP8266, and so on.

In the world of LEDs, the part that most immediately springs to mind is the Worldsemi WS2812 addressable LED. This part consists of three LEDs in red, green, and blue, all in the same package with a serial interface allowing a chain of individually addressable multicolour lights to be created. We’ve seen them in all sorts of places, and if you don’t recognise the part number then perhaps you will by one of the names they’re sold under: Neopixel.

Yesterday we received an email from our piratical friends at Pimoroni, the British supplier of all forms of electronic goodies. Among their range they have a reasonable number of products containing WS2812s, and it was these products that had formed the subject of an unexpected cease-and-desist letter. APA Electronic are the manufacturer of the APA102 addressable LED (which you may know as the Dotstar), and their cease-and-desist asking for the products to be withdrawn from sale rests on their holding a patent for an addressable multicolour LED. We’d be very interested to hear whether any other suppliers of WS2812-based parts have received similar communications.

US patent number 8094102B2 is indeed a patent for a “Single full-color LED with driving mechanism”, which does look a lot like a WS2812. But as always, such things are not as cut-and-dried as they might first appear. The LED in the patent for example relies upon a clock line for its operation, while the Worldsemi part doesn’t. I am not a lawyer so I’d hesitate to call this a baseless and speculative move, but I suspect that there will be plenty over which the two semiconductor companies can duke it out in the courtroom.

It’s fair to say that a large part of the ethos of our movement shares something with that of the world of open-source, so news of legal manoeuvres such as this are never likely to go down well. We’re small fry in this context and our commercial influence on APA102 or WS2812 sales will be minimal, but inevitably APA’s standing in our eyes will be diminished. Companies such as Pimoroni are not the target but a piece of collateral damage in a battle between manufacturers.

Whether the patent has been violated or not can only be decided by the courts. It is not uncommon for patent holders to go after companies selling the “infringing” products in hopes that rather than risk a costly court battle, they simply adhere to the demands, in this case buying parts from APA and not from Worldsemi.

So, if you rely on addressable LEDs, watch out! There may be trouble ahead.

Header image: Tristan Robitaille [CC BY-SA 4.0].