Balancing Robots From Off-The-Shelf Parts

October 17, 2018 by Lewin Day 4 Comments

In this day and age, we are truly blessed as far as the electronics hobby is concerned. Advanced modules such as gyros and motor controllers are readily available, not just as individual parts, but as pre-soldered modules that can be wired together with a minimum of fuss and at low cost. This simple balancing robot is a great example of what can be done with such parts (Google Translate link).

The robot has an ESP32 running the show, which provides both the processing power required, as well as the WiFi interface used to control the ‘bot from a smartphone. This is achieved using an app from JJRobots, an open-source robotics teaching resource. Stepper motors are controlled by DRV8825 modules sourced from amazon, and an MPU6050 gyro rounds out the major components. Naturally, source code is available on GitHub for your reading pleasure.

It’s remarkable that in this day and age, it’s possible to build such a project with little to no soldering required at all. With a credit card and a healthy supply of patch leads, it’s possible to whip up complex digital projects quite quickly. We’ve seen a similar approach before, too. Video after the break.

[Thanks to Baldpower for the tip!]
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Arcade Asteroids, Now In Colour

October 13, 2018 by Lewin Day 11 Comments

Asteroids is one of the classic games of the early arcade era. Launched in 1979 by Atari, it relied upon using an XY vector monitor to deliver crisp graphics for its space-based gameplay. One of the limitations of the original arcade games was that the game was only rendered in a single colour, white. Over 30 years later, [Arcade Jason] decided to see what it would take to build a color Asteroids machine.

The ROM hack also modified the shapes of several in-game objects.

The hack relies on the fact that the original game used a four-bit resistor ladder DAC to draw vectors in different intensity levels. Through some ingeniously simple hardware, this DAC is repurposed to denote different colours instead. It’s laced together with a 74LS08 AND gate chip, along with a handful of resistors and diodes. Three bits are used for red, green, and blue, respectively, with the fourth used as a “white boost” signal to allow the differentiation of colours like red and pink, or dark and light blue. It’s then all wired into an RGB vector monitor for final display. After that, it’s just a matter of a simple ROM hack to set the colors of various on screen objects.

Vector monitors are notoriously hard to film well, but it’s clear that in person the output is rather impressive. Making color versions of old retro games is actually a hobby of [Arcade Jason]’s – we’ve featured his color Vectrex before. Video after the break.

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Save A Linotype Machine For Future Generations

October 13, 2018 by Jenny List 57 Comments

The journalist’s art is now one of the computer keyboard and the internet connection, but there was a time when it involved sleepless nights over a manual typewriter followed by time spent reviewing paper proofs freshly inked from hot lead type. Newspapers in the golden age of print media once had entire floors of machinery turning text into custom metal type on the fly, mechanical masterpieces in the medium of hot lead of which Linotype were the most famous manufacturer.

Computerised desktop publishing might have banished the Linotype from the newsroom in the 1970s or 1980s, but a few have survived. One of the last working Linotypes in Europe can be found in a small print workshop in Vienna, and since its owner is about to retire there is a move to save it for posterity through a crowdfunding campaign. This will not simply place it in a museum as a dusty exhibit similar to the decommissioned Monotype your scribe once walked past every day in the foyer of the publishing company she then worked for, instead it will ensure that the machine continues to be used on a daily basis producing those hot metal slugs of type.

Fronting the project is [Florian Kaps], whose pedigree in the world of resurrecting analogue technologies was established by his role in saving the Polaroid film plant in Enschede, Netherlands. There are a variety of rewards featuring Linotype print, and at the time of writing the project is 46% funded with about four weeks remaining. If you are curious about the Linotype machine and its operation, we’ve previously brought you an account of the last day of hot metal printing at the New York Times.

Swedish Front Plus Japanese Back Makes For Useful Hybrid Camera

October 11, 2018 by Dan Maloney 8 Comments

Professional or amateur, doing things the hard way doesn’t always make for better results. Take photography as an example. Once upon a time, the success or failure of what happened during the instant that the camera’s shutter was open was only known hours or days later after processing the film. Ruin the shot with bad exposure or suboptimal composition? Too bad. Miss a once-in-a-lifetime moment as a result? Ouch.

Once instant photography came along, pros were quick to adopt it as a quick and dirty way to check everything before committing the shot to higher-quality film. Camera manufacturers made special instant film cartridges that could be swapped for roll film, and charged through the teeth for them. Unwilling to shell out big bucks, [Isaac Blankensmith] hacked his own instant film back for his Hasselblad medium-format camera. The unlucky donor camera was a Fujifilm Instax, a camera that uses film packs similar to those used by Polaroid and Kodak instant cameras from the 70s and 80s. Several of these cameras were dissected – carefully; those flash capacitors pack a wallop – and stripped down to the essential film-handling bits. An adapter was fabricated from laser-cut acrylic to mount the film back to the Hasselblad, with care taken to match the original focal plane. The shots are surprisingly good; despite a minor light leak from the adapter, they’re fine for the purpose. The best part: the whole build took just 48 hours from conception to first shots.

Speaking of Polaroid, we’ve featured quite a few hacks of Edwin Land’s venerable cameras over the year. From replacing the film with a printer to an upgrade to 35-mm film, instant cameras in general and Polaroids in particular seem to have quite a following among hackers.

Thanks for tipping us off, [macsimski].

Adding Bluetooth To Original SNES Controllers

October 10, 2018 by Tom Nardi 14 Comments

There’s a bunch of companies selling wireless Super Nintendo style controllers out there. You can go on Amazon and get any number of modern pads that at least kinda-sorta look like what came with Nintendo’s legendary 1990’s game console. They’ve got all kinds of bells and whistles, Bluetooth, USB-C, analog sticks, etc. But none of them are legitimate SNES controllers, and for some people that’s just not good enough.

[sjm4306] is one of those people. He wanted to add Bluetooth and some other modern niceties to a legitimate first-party SNES controller, so he picked up a broken one off of eBay and got to work grafting in his custom hardware. The final result works with Nintendo’s “Classic Edition” consoles, but the concept could also work with the original consoles as well as the computer if you prefer your classic games emulated.

A custom ATMEGA328P-powered board polls the controller’s SPI serial shift register in much the same way the original SNES would have. It then takes those button states and sends them out over UART with a HC-05 Bluetooth module. The controller is powered by a 330 mAh 3.7V battery, and a charging circuit allows for easily topping the controller off with a standard USB cable.

A particularly nice touch on the controller is the use of custom light pipes for the status LEDs. [sjm4306] made them by taking pieces of transparent PLA 3D printer filament, heating and flattening the end, and then sanding it smooth. This provides a diffusing effect on the light, and we’ve got to say it looks very good. Definitely a tip to file away for the future.

On the receiving side, this project was inspired by a custom NES Classic Edition Advantage controller we featured last year, and borrows the work creator [bbtinkerer] did to get his receiver hardware talking to the Classic console over I2C.

We’ve seen a number of projects which have added wireless functionality to the classic Super Nintendo controller, but most tend to be more invasive than this one. We like the idea of reading the controller’s original hardware rather than completely gutting it.

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The Bells! The Bells! One Battery Since 1840

October 7, 2018 by Al Williams 18 Comments

It is good advice to change batteries in your fire alarms at least once a year. Even our low-power LCD calculators need new batteries from time to time. But at the University of Oxford, they have an electric bell that has been ringing essentially non-stop on one set of batteries for about 178 years! Is the energy crisis solved then? Perhaps not. The bells require a high voltage but very little current and the pair of batteries — piles in the parlance of 1840 — have kept the charge flowing for about 10 billion rings. As you can see in the video below, though, the ringing isn’t very vigorous.

How does it work? When you think of converting electrical power to mechanical motion you probably think of a motor, even though there are plenty of other transducers like speakers, muscle wires, and solenoids. Arguably the first device was electrostatic bells that were invented by a Scot named [Andrew Gordon] around 1742. [Ben Franklin] made them famous, though, so they are often called Franklin bells.

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Bus Raider Allows Classic Micro Emulation On An RC2014

October 6, 2018 by Jenny List 12 Comments

If you were lucky enough to own one of the crop of 1980s 8-bit computers, did you ever pause to consider how its graphics worked? Maybe the really expensive ones had dedicated CRT controller subsystems akin to the graphics cards you’d have found on a PC a few years later, but most of the affordable models would have stopped what they were doing every TV line interval period to allow access to their memory for their graphical output to be created.

The RC2014 retrocomputer dodges all this, by using a serial port as an interface and expecting your serial terminal to handle the screen. But what if it could produce its graphics directly as the machines of old did? [Rob Dobson] set out to achieve this, and not only did he succeed but he also found a way to directly emulate some classic machines along the way.

His RC2014 card which he calls the Bus Raider started as an attempt to use a Raspberry Pi to commandeer the RC2014 memory and read it via its GPIO lines, interpreting the graphics for its own screen. But even with bare metal Pi programming he couldn’t achieve the complex timing required for that, so he took an alternative approach. He ended up with an ESP32 that emulates a custom part of the RC2014 memory map and generates a display from there. Having created a custom memory map and hardware emulator for his RC2014, he then had the revelation that he could emulate any memory map, and thus he could make the retrocomputer perform natively as though it were any of a selection of classic micros. So far as well as a straight serial terminal he has a Sinclair ZX Spectrum and a Radio Shack TRS-80 running, as well as his own custom Z80 environment. And since the ESP32 also has WiFi, he can even connect to it through that medium.

Retrocomputers are something in which you might think that everything possible would already have been done, but projects like this one never cease to amaze us with their ingenuity. If you’d like to read more about the RC2014, we reviewed an earlier model back in 2016.