Raspberry Pi Powers This Retro Chess Computer

January 6, 2019 by Tom Nardi 15 Comments

If you imagine somebody playing chess against the computer, you’ll likely be visualizing them staring at their monitor in deep thought, mouse in hand, ready to drag their digital pawn into play. That might be accurate for the folks who dabble in the occasional match during their break, but for the real chess aficionados nothing beats playing on a real board with real pieces. Of course, the tricky part is explaining the whole corporeal thing to a piece of software on your computer.

Enter the “Chess Challenger” by [slash/byte]. Modeled after a commercial gadget of the same name from 1978, his retro-themed open hardware design utilizes the Raspberry Pi Zero and modern chess software to bring the vintage concept into the 21st century. With the Chess Challenger and a standard board, the player can face off in an epic battle of wits against the computer without risk of developing carpal tunnel. We can’t guarantee though that a few boards might not get flipped over in frustration.

The pocket sized chess computer uses a “sandwich” style construction which shows off the internals while still keeping things reasonably protected. All of the electronics are housed on the center custom PCB which features a HT16K33 driver for the dual LTP-3784E “starburst” LED displays, a MCP1642B voltage regulator, 16 TL3305 tactile switches for the keyboard, and a MCP73871 battery management chip for the 3.7 volt lithium-ion battery that powers the whole show. The Pi Zero itself connects to the board by way of the GPIO header, and is mechanically supported by the standoffs used to hold the device together.

On the software side of things, the Pi is running the mature Stockfish open source chess engine. In development now for over a decade, this GPL licensed package aims to deliver a world-class chess gameplay on everything from smartphones to desktop computers, and we’ve seen it pop up in a number of projects over the years. [slash/byte] has provided a ready to flash SD card image for the Raspberry Pi, and even provides detailed installation and setup instructions which guide you through some of the more thorny aspects of the setup such as getting the Pi running from a read-only operating system so that abrupt power cuts don’t clobber the filesystem.

Over the years, some of the most impressive projects we’ve seen revolved around playing chess, and this latest entry by [slash/byte] is no exception. Another example of the lengths the chess community will go to perfect the Game of Kings.

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RC Controller Becomes XInput Controller

January 5, 2019 by Lewin Day 4 Comments

XInput is an API that is used by applications to interface with the Xbox 360 Controller for Windows. The 360 controller became somewhat of a “standard” PC gamepad, and thus many games and applications support the XInput standard.

[James] is working on an entry for a robotics competition, and wanted a controller to use with their PC that was more suited to their build. They took an RC controller, and converted it to work with XInput instead.

The controller in question is the JJRC Q35-01, a trigger-type RC controller available for under $20. The conversion is executed neatly, with the original STM microcontroller being removed from the board, and the PCB traces instead being connected to a Teensy 3.5 which takes over running the show.

The conversion is remarkably complete, with the team not stopping at just reading the buttons and steering potentiometer. A USB logic analyzer was used to figure out how to control the LCD, and a calibration mode implemented just in case.

[James] has shared the work on Github so it’s reproducible for the average maker. We’ve seen plenty of builds in this space, like this tilt controller from [Electronoobs]. Video after the break.

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A Foggy Lightsaber Build

January 4, 2019 by Lewin Day 5 Comments

Lightsabers have enchanted audiences since their appearance in the very first Star Wars film in 1977. Unfortunately, George Lucas hasn’t shared the technology in the years since then with the broader public, so we’re left to subsist on pale imitations. This is just such a build.

The closest human analog to Jedi technology is the laser, and this build uses 8 of them in combination with two LEDs. They’re aimed to coincide at a fixed distance above the hilt. A CO2 bicycle inflater is then used to blow through an e-cigarette to create a fog. This makes the red lasers readily visible to the human eye.

This ersatz lightsaber does have its limitations – fast motion tends to scatter the fog, making it once again invisible, and it’s really at its best held in a vertical orientation. There’s also some divergence beyond the focused point. With that said, it does look somewhat impressive when held still, smouldering away.

Until we gain a better mastery of plasma physics, perhaps you can make do with this fire-based build? Video after the break.

[Thanks to qrp-gaijin for the tip!]

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1973: When Calculators Were Built Like Computers

January 2, 2019 by Jenny List 55 Comments

Should you ever pick up [Steve Wozniak]’s autobiography, you will learn that in the early 1970s when his friend [Steve Jobs] was working for Atari, [Woz] was designing calculators for Hewlett Packard. It seems scarcely believable today, but he describes his excitement at the prospects for the calculator business, admitting that he almost missed out on the emerging microcomputer scene that would make him famous. Calculators in the very early 1970s were genuinely exciting, and were expensive and desirable consumer items.

[Amen] has a calculator from that period, a Prinztronic Micro, and he’s subjected it to an interesting teardown. Inside he finds an unusual modular design, with keyboard, processor, and display all having their own PCBs. Construction is typical of the period, with all through hole components, and PCBs that look hand laid rather than made using a CAD package. The chipset is a Toshiba one, with three devices covering logic, display driver and clock.

The Prinztronic is an interesting device in itself, being a rebadged 1972 Sharp model under a house brand name for the British retailer Dixons, and that Toshiba chipset is special because it is the first CMOS design to market. It was one of many very similar basic calculators on the market at the time, but at the equivalent of over 100 dollars in today’s money it would still have been a significant purchase.

Long-tern Hackaday readers will remember we’ve shown you at least one classic calculator rebuild in the past, the venerable 1975 Sinclair!

Forcing Amazon Alexa Compatible Stuff To Speak To Google Assistant

January 1, 2019 by Lewin Day 21 Comments

It took a long time, but it’s 2019, and we’re starting to get used to the concept of talking to a computer to make it control things around the house. It’s not quite as cool as it seemed when we saw it in films way back when, but that’s just real life. The problem is, there’s a multitude of different systems and standards and they don’t all necessarily work together. In [Blake]’s case, the problem is that Woods brand hardware only works with Amazon Alexa, which simply won’t do.

[Blake] went through the hassle of getting an Amazon Alexa compatible WiFi outlet to work with Google Assistant. It’s a bit of a roundabout way of doing things, but it works. A TP-Link HS-105 WiFi plug is used, which can be controlled through Google Assistant voice commands. The part consists of two PCBs – a control board that speaks WiFi, and a switching board with relays. [Blake] used the control board and hooked it up to a Raspberry Pi. When switched on by a command from Google, the HS-105 sets a pin high, which is detected by the Raspberry Pi. The Raspberry Pi then runs a software implementation of the KAB protocol used by the Woods hardware, triggering it when it receives the signal from the TP-Link hardware.

If we understand correctly, [Blake] had to go to this trouble in order to make his special outdoor-rated outlets work with his Google Home setup. Hopefully interoperability improves in years to come, but we won’t hold our breath.

We’ve seen some pretty convoluted projects in this space before, often using IFTTT — like this ESP8266 voice controlled tank.

Netflix Drops ZX Spectrum Homebrew Title Nohzdyve

January 1, 2019 by Drew Littrell 13 Comments

The dark, dystopian future is ever-present in the Netflix show Black Mirror, but the latest release in the series, Bandersnatch, presents a decidedly different narrative. Bandersnatch is a branching story that follows the fictional events of a garage-programmer named Stephan who develops the titular game, Bandersnatch, for the Tuckersoft company set in 1980s England. The whole thing plays out as a choose-your-own adventure game fit straight off the Sega CD (albeit with actual full motion video) by allowing watchers to pick what happens next in the story. Not one to miss a cross-promotional opportunity, Netflix also released a playable ZX Spectrum homebrew title, Nohzdyve, developed by a friend of Hackaday, [Matt Westcott].

Keen viewers of Bandersnatch were able to ascertain that the screeching sound at the end of the show when loaded into a ZX Spectrum would display a QR code. That in turn led to a real website for the fake Tuckersoft company (thankfully in HTML). The website itself showcases the fictional company’s software library and upcoming releases, but it also took things a step further. The duality of Bandersnatch is carried over to the website as there are branching paths for those that remove ‘www’ from the URL. Doing so reveals Tuckersoft’s website from an alternate timeline where Bandersnatch was never created, however, a downloadable copy of Nohzdyve in a .tap file is there for the taking.

The Nohzdyve game itself is a vertically scrolling action game that uses the ZX Spectrum’s garish color palette to great effect. Racking up a high score in the game can be done via emulator (for example Speccy) or for the most authentic experience, on real hardware. This may be the best reason to fire up a tape drive in a while, but for those seeking the less-analog approach there is always this gameplay footage from Mr. Tom FTW’s channel:

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Designing Tiny Motors Right Into The Robot’s Circuit Board

January 1, 2019 by Mike Szczys 10 Comments

Motors are not overly complex, but this one is downright simple. Carl Bujega has been working on a motor design that heavily relies on the capabilities of the printed circuit board (PCB) fabrication processes. His talk at the 2018 Hackaday Superconference covers how he built a brushless DC motor and speed controller into a PCB. You can watch the newly published video after the break.

There are two main parts of an electric motor; the stator is stationary while the rotor spins on bearings. Electromagnetic forces are used to cause that spinning action. In this case, Carl has built the electromagnets as coils on a 4-layer circuit board (six coils on each layer). When electrified, a magnetic field is generated that pushes against the rare-earth magnets housed in the rotor.

A couple of things are really interesting here. First, those coils are usually made of “magnet wire” (enamel covered wire that is very thin) wrapped around an iron core. Using the circuit board instead saves both physical space, and the time and expense of wrapping coils of wire in the traditional way. Second, Carl has been designing with manufacture in mind; you can see in the image show that his motor design is dead-simple to assemble by inserting a 3mm bearing in the PCB, inserting magnets into the plastic rotor and snapping it into place. The end goal is to make robot actuators that are part of the circuit board itself.

The genesis of this idea came from Carl’s interest in drone design, in fact, he jumped right into a drone startup immediately after finishing his EE. The company didn’t last, but his thirst for interesting designs is ongoing. When looking at reducing the total parts necessary to build a quadcopter he happened on the idea of PCB-based coils and he’s followed it to this motor design, and beyond to some very interesting flexible-PCB robot design work which you can check out on his Hackaday.io page, YouTube, and Twitter.

There are of course some trade-offs to this. The motor is low torque since it uses an air core and not an iron core. And he’s had trouble implementing a sensor-less Electronic Speed Controller (ESC) as the back-EMF from the coils appears to be too weak. Not to fret, he added a hall sensor and has succeeded in designing an ESC that measures just 14mm by 8mm. In fact, he’s holding up the ESC and motor in the image at the top of this article!

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