There’s RC2014 Life In The TMS9918A Display Chip Yet

June 22, 2018 by Jenny List 30 Comments

One of the outliers in the home computer wars of the early 1980s was the Texas Instruments TI99/4A. It may not have had the games library of its rivals and its TMS9900 processor may not have set the world on fire with its registers-in-RAM architecture, but its range of support chips included one whose derivatives would go on to delight subsequent generations. If you had an MSX or one of the 8 or 16-bit Sega consoles, the TMS9918A graphics chip provided the architecture that sat behind Sonic in his adventures.

A few decades later, there is still significant interest in this classic chip. [J.B. Langston] has an RC2014 retrocomputer, and wishing to play MSX demos upon it, has created a TMS9918A-based graphics card for the RC2014 bus. The success of the board hinges upon a circuit showing how to interface the 9918A to SRAM, and since it is mapped to the same ports as its MSX equivalent it should in theory be compatible with Z80 demos written for that platform. He’s already achieved some success with that aim, as can be demonstrated by the video we’ve placed below the break of the Bold MSX demo running on an RC2014.

The RC2014 has gained a significant following in the retrocomputer scene, and has appeared here many times. We reviewed an early model in 2016. Surprisingly though the TMS9918A has only appeared here once, as part of a homebrew 6809-based system.

Continue reading “There’s RC2014 Life In The TMS9918A Display Chip Yet” →

CNC Mod Pack Hopes To Make Something Useful From A Cheap Machine Tool

June 21, 2018 by Jenny List 13 Comments

It is probable that many of us have noticed a variety of very cheap CNC mills in the pages of Chinese tech websites and been sorely tempted. On paper or as pixels on your screen they look great, but certainly with the more inexpensive models there soon emerges a gap between the promise and the reality.

[Brandon Piner] hopes to address this problem, with his CNC Mod Pack, a series of upgrades to a cheap mill designed to make it into a much more useful tool. In particular he’s created a revised 3D-printed tool holder and a set of end stop switches. The tool holder boasts swappable mounts on a dovetail fitting with versions for both a laser diode and a rotary tool, allowing much better tool positioning. Meanwhile the end stops are a necessary addition that protects both tool and machine from mishaps.

The same arguments play out in the world of small CNC mills as do in that of inexpensive 3D printers, namely that the economy of buying the super-cheap machine that is nominally the same as the expensive one starts to take a knock when you consider the level of work and expense needed to make your purchase usable. But with projects like this one the barrier to achieving a quality result from an unpromising start is lowered, and the enticing prospect is raised of a decent CNC machine for not a lot.

Clock This! A 3D-Printed Escapement Mechanism

June 21, 2018 by Jenny List 13 Comments

Traditional mechanical clockmaking is an art that despite being almost the archetype of precision engineering skill, appears rarely in our world of hardware hackers. That’s because making a clock mechanism is hard, and it is for good reason that professional clockmakers serve a long apprenticeship to learn their craft.

Though crafting one by hand is no easy task, a clock escapement is a surprisingly simple mechanism. Simple enough in fact that one can be 3D-printed, and that is just what [Josh Zhou] has done with a model posted on Thingiverse.

The model is simply the escapement mechanism, so to make a full clock there would have to be added a geartrain and clock face drive mechanism. But given a pair of 608 skateboard wheel bearings and a suitable weight and string to provide a power source, its pendulum will happily swing and provide that all-important tick. We’ve posted his short video below the break, so if Nixie clocks aren’t enough for you then perhaps you’d like to take it as inspiration to go mechanical.

A pendulum escapement of this type is only one of many varieties that have been produced over the long history of clockmaking. Our colleague [Manuel Rodriguez-Achach] took a look at some of them back in 2016.

Continue reading “Clock This! A 3D-Printed Escapement Mechanism” →

Hexabitz, Modular Electronics Made Easier

June 20, 2018 by Jenny List 14 Comments

Over the years there have been a variety of modular electronic systems allowing the creation of complex circuits by the interconnection of modules containing individual functions. Hexabitz, a selection of interlocking polygonal small PCBs, is just such a system. What can it bring to the table that others haven’t done already?

The problem facing designers of modular electronics is this: all devices have different requirements and interfaces. To allow connection between modules that preserves all these connections requires an ever-increasing complexity in the inter-module connectors, or the application of a little intelligence to the problem. The Hexabitz designers have opted for the latter angle, equipping each module with an STM32 microcontroller that allows it to identify both itself and its function, and to establish a mesh network with other modules in the same connected project. This also gives the system the ability to farm off computing tasks to individual modules rather than relying solely upon a single microcontroller or single-board computer.

An extremely comprehensive array of modules can be had for the system, which lends it some interesting possibilities, however, it suffers from the inherent problem of modular electronic systems, that it is less easy to incorporate non-standard functions. If they can crack a prototyping module coupled with an easy way to tell its microcontroller to identify whatever function is upon it, they might have a winner.

Definitely-Not-Neopixel Rings, From Scratch!

June 16, 2018 by Jenny List 22 Comments

The WS2812 addressable LED is a marvellous component. Any colour light you want, all under the control of your favourite microcontroller, and daisy-chainable to your heart’s content. Unsurprisingly they have become extremely popular, and can be found in a significant number of the project s you might read about in these pages.

A host of products have appeared containing WS2812s, among which Adafruit’s Neopixel rings are one of the more memorable. But they aren’t quite as cheap as [Hyperlon] would like, so the ever-resourceful hacker has created an alternative for the constructor of more limited means. It takes the form of a circular PCB that apes the Adafruit original, and it claims to deliver a Bill of Materials cost that is 85% cheaper.

In reality the Instructables tutorial linked above is as much about how to create a PCB and surface-mount solder as it is specific to the pixel ring, and many readers will already be familiar with those procedures. But we won’t rest until everyone out there has tried their hands at spinning their own PCB project, and this certainly proves that such an endeavour is not out of reach. Whether or not you pay for the convenience of the original or follow this lead is your own choice.

The real thing has been in so many projects it’s difficult to pick just one to link to. This Christmas tree is rather nice.

A 3D-Printed Robot Actuator

June 16, 2018 by Jenny List 18 Comments

Somehow, walking robots at our level never really seem to deliver on the promise that should be delivered by all those legs. Articulation using hobby servos is simple enough to achieve, but cumbersome, slow, and not very powerful. [Paul Gould] has a plan to make a better, 3D-printed articulated robot actuator.

His solution is both novel and elegant, a fairly conventional arm geometry that has at its joints a set of brushless motors similar to but a little larger than the kind you might be more familiar with on multirotors, paired with 3D-printed cycloidal gearboxes. Magnetic encoders provide the necessary positional feedback, and the result is a unit that is both compact and powerful.

With such a range of small brushless motor controllers on the market, it’s at first sight unexpected that he’s designed his own controller board. But this gives him complete control over his software, plus the CAN bus that ties everything together. He’s given us a video which we’ve placed below the break, showing the build process, the impressive capabilities of his system, and a selection of builds including a robot dog complete with tail. This is definitely a project to watch.

Continue reading “A 3D-Printed Robot Actuator” →

Field Trip! Hackaday Visits Pimoroni

June 14, 2018 by Jenny List 31 Comments

If you have a Raspberry Pi and have any interest in its peripherals, you may be familiar with the grinning pirate logo of the British company, Pimoroni. The Sheffield, UK based outfit first established a niche for itself as one of the go-to places for much of the essentials of Pi ownership, and has extended its portfolio beyond the Pi into parts, boards, and components across the spectrum of electronic experimentation. Their products are notable for their distinctive and colourful design language as well as their constant exploration of new ideas, and they have rapidly become one of those companies to watch in our sphere. On our way up to Newcastle for Maker Faire UK, we passed close enough to the Pimoroni HQ to be able to ask nicely if we could drop in and have a tour.

[Paul] showing off some of the Pimoroni attention to design detail. This artwork is hidden behind a display panel on the finished product. — Paul showing off some of the Pimoroni attention to design detail. This artwork is hidden behind a display panel on the finished product.

The Pimoroni HQ can be found in a nondescript unit with a discreetly placed sign on an industrial estate after a short drive through the city from the motorway. Inside it’s the same as thousands of other units, a set of offices at the front and a cavernous warehouse behind, except this one is filled with the kinds of goodies that get our blood pumping! And we’re told this ~~toybox~~ warehouse is soon to be joined by another nearby unit, as the Pimoroni business is expanding.

Our guide was the company co-founder Paul Beech, whose work you will be familiar with even if this is the first time you’ve heard his name; Paul was the designer of the Raspberry Pi logo! The company is not exclusive to that platform but it’s fair to say they have a strong connection with the Pi, starting in 2012 with as their website puts it: “One laser cutter and a kettle” on which they produced the first of their iconic PiBow laser-cut sandwich Raspberry Pi cases.

Continue reading “Field Trip! Hackaday Visits Pimoroni” →