The 7400 Quad 2-Input NAND Gate, A Neglected Survivor From A Pre-Microprocessor World

December 28, 2018 by Jenny List 63 Comments

There are a range of integrated circuits that most of us would regard as definitive examples of their type, devices which became the go-to for a particular function and which have entered our collective consciousness as electronics enthusiasts. They have been in production since the early days of consumer integrated circuits, remaining in use because of a comprehensive understanding of their characteristics among engineers, and the job they do well.

You can probably name the ones I’m going to rattle off here, the µA741 op-amp designed by David Fullagar for Fairchild in 1968, the NE555 timer from Hans Camenzind for Signetics in 1971, and a personal favourite, Bob Widlar’s µA723 linear regulator for Fairchild in 1967. There may be a few others that readers will name in the comments, but there’s one that until today it’s likely that few of you would have considered. Texas Instruments’ 5400 and 7400 TTL quad 2-input NAND gate has been in continuous production since 1964 and is the progenitor of what is probably the most numerous breed of integrated circuits, yet it doesn’t trip off the tongue when listing famous chips, and none of us can name its designer. So today we’re turning the spotlight on this neglected piece of silicon, and trying to bring it the adulation it deserves. Continue reading “The 7400 Quad 2-Input NAND Gate, A Neglected Survivor From A Pre-Microprocessor World” →

Motorize Your Camera Slider, The Hacker Way

December 27, 2018 by Lewin Day 11 Comments

Camera sliders are a fantastic tool for those who wish to shoot beautiful and smooth panning video, or take expressive time-lapse shots. They can also be remarkably expensive, which creates an incentive for the DIYer to innovate at home. [Richard] wanted a motorized slider and didn’t want to break the bank, and thus, a build was born.

Starting with an existing non-motorized camera slider makes things easier, though there’s no reason [Richard]’s techniques couldn’t be applied to a completely DIY build. A NEMA stepper motor is fitted to the frame, and connected to the camera shuttle with a toothed belt. The stepper is controlled by an Arduino, which allows for both timelapse and smooth panning modes, and can be controlled with an IR remote sourced from Amazon. The slider is also interfaced with a Processing sketch, which gives a graphical representation of the slider’s current position on the laptop’s screen, which helps for setting up a shot.

[Richard] has shared the code and a shopping list, and is confident that the build can be completed for under $100. That’s a satisfying price given the quality of shots possible with a good slider.

We see plenty of slider builds here, including this impressive pantograph-type build. Video after the break.

[Thanks to Baldpower for the tip!]

Continue reading “Motorize Your Camera Slider, The Hacker Way” →

Doomba Transports Your Living Room To Hell

December 27, 2018 by Tom Nardi 11 Comments

Despite being over 25 years old, the original DOOM is still a favorite among gamers and hackers alike. For years now, running the 1993 demonic shooter has been a critical milestone when hacking or reverse engineering a piece of gear, and at this point we’ve seen it run on everything from voting machines to cameras.

But this time around, DOOM isn’t actually running on the device being hacked. Instead, the Roomba 980 that [Rich Whitehouse] has doing his bidding is being used to generate new DOOM levels based on the maps it makes of rooms while going about its business. To be fair they’re pretty simplistic maps, and most of us don’t live in a home quite palatial enough to even fill out shareware trial of id Software’s classic, but it’s still a neat trick.

For those who might not be up to date with the latest and greatest in the world of robotic helpers, newer model Roomba vacuums are equipped with a camera and the ability to generate 3D maps of its environment using a technique called Vision Simultaneous Localization and Mapping (VSLAM). Ostensibly this capability is used to create accurate maps of hazards in the cleaning area, but of course it did set off some privacy alarm bells when introduced due to the possibility that scans of users homes could end up being used for nefarious purposes. Roomba manufacturer iRobot swears they aren’t doing anything suspect with the data their robots collect while traveling through the user’s home, but that hasn’t stopped [Rich] from using the technology as a portal to Hell.

Using “DOOMBA”, the user is able to download the mapping data off of their Roomba 980 (it might work on other models, but hasn’t been tested yet) over the local network and import it into Noesis, a 3D model viewing program developed by [Rich]. The imported map is essentially just a 2D diagram of the home’s floor plan, which on its own wouldn’t make for a terribly interesting DOOM level, so the software will take the liberty of seeding it with weapons, baddies, and all the other varied delights of the netherworld. The user can fiddle around with these settings to try and fine-tune their homespun hellscape, or just let “DOOMBA” randomize it all so they can get on with the ripping and tearing.

If you’ve got Roomba in hand but aren’t a DOOM fan, have no fear. We’ve seen plenty of hacks and mods for everyone’s favorite house-cleaning hockey puck which happen to be of the non-demonic variety. If you just can’t get enough DOOM, stick around for tomorrow’s 25th anniversary celebration article. You will want to copy the banner art and use it as your new desktop background.

Word Clock Don’t Need No Stencil Font

December 26, 2018 by Lewin Day 9 Comments

Word clocks use natural language to display the time. They’ve been in vogue in the last 20 years or so, as low-cost digital technology makes them particularly cost effective and easy to build for the average maker. The hardware and software is a solved problem, so presentation is everything. Luckily, [watsaig]’s effort does not disappoint.

The build began with a timeframe of just seven days — a narrow window given [watsaig]’s lack of experience with lasercutting and woodworking. Not content to let that get in the way, it was time to get to work. Wood was sourced from Amazon and designs laid out, before lasercutting began in earnest.

[watsaig] decided to fill all of the letters with epoxy to achieve a flat finished surface that also served as diffuser for the LEDs. To avoid using an unsightly stencil font, the centers (the cut out portion) of letters like O, A, and R had to be placed by hand. Unfortunately his turned out quite badly. When using a squeegee method to work epoxy into the letters, the inserts tended to shift, ruining the face plate.

Undeterred, the clock face was recreated from scratch, and it was determined that a pipette was a far more suitable tool, allowing the letters to be filled with epoxy without unduly disturbing the letter inserts. The final result is visually attractive, finished with a wonderful stain and giving a pleasing glow thanks the careful attention to diffusion and masking. The hidden Happy Birthday message may have been lost in the rush, but it’s the thought that counts, after all.

For a Continental take, check out this word clock in Catalan.

Delicious Vector Game Console Runs Pac-Man, Tetris, And Mario

December 26, 2018 by Dan Maloney 20 Comments

The only question we have about [mitxela]’s DIY vector graphics game console is: Why did he wait five years to tell the world about it?

Judging by the projects we’ve seen before, from his tiny LED earrings to cramming a MIDI synthesizer into both a DIN plug and later a USB plug, [mitxela] likes a challenge. And while those projects were underway, the game console you’ll see in the video below was sitting on the shelf, hidden away from the world. That’s a shame, because this is quite a build.

Using a CRT oscilloscope in X-Y mode as a vector display, the console faithfully reproduces some classic games, most of which, curiously enough, were not originally vector games. There are implementations of the Anaconda, RetroRacer, and AstroLander minigames from Timesplitter 2. There are also versions of Pac-Man, Tetris, and even Super Mario Brothers. Most of the games were prototyped in JavaScript before being translated into assembly and placed onto EEPROM external cartridges, to be read by the ATMega128 inside the console. Sound and music are generated using the ATMega’s hardware timers, with a little help from a reverse-biased transistor for white noise and a few op-amps.

From someone who claims to have known little about electronics at the beginning of the project, this is pretty impressive stuff. Our only quibbles are the delay in telling us about it, and the lack of an Asteroids implementation. The former is forgivable, though, because the documentation is so thorough and the project is so cool. The latter? Well, one can hope.

Continue reading “Delicious Vector Game Console Runs Pac-Man, Tetris, And Mario” →

The Umbrella That Tells You The Weather

December 25, 2018 by Lewin Day 12 Comments

Most people can tell you the various uses of the umbrella — it keeps the rain off, pokes sleeping train passengers awake, and can be used as an improvised defensive weapon when tension in the hot dog line reaches boiling point. A true Englishman would never deign to employ their brolly so imprudently, of course, but they might just give it an upgrade by packing in a full weather station.

Please do not message us to complain about the redundancy of a rain sensor on an umbrella.

The build uses the Particle Photon as the brains of the operation, interfacing it with several sensors. There’s a DHT11 to handle temperature and humidity measurement, an Adafruit barometric pressure sensor, along with a custom-built anemometer using a brushed motor with 3D printed wind cups. Finally, a breadboard is turned into a rain detector, based on the same principles as those used in automotive applications.

The Particle Photon uses WiFi to tether to a smartphone, deliver the collected data to the cloud via Adafruit IO. This enables the data to be collated and processed further on a PC. Yes, it’s 2018, and they have the internet on umbrellas now.

As we reach further into the depths of winter, it’s one project that could very much come in handy, and [The Gentlemen Maker] has been kind enough to share the code on Particle.io. If that’s not good enough, perhaps you could use your umbrella as a WiFi antenna. Video after the break.

Continue reading “The Umbrella That Tells You The Weather” →

Vintage Toys Live On Through 3D Printing

December 24, 2018 by Tom Nardi 5 Comments

We all have fond memories of a toy from our younger days. Most of which are still easy enough to get your hands on thanks to eBay or modern reproductions, but what if your childhood fancies weren’t quite as mainstream? What if some of your fondest memories involved playing with 1960’s educational games which are now so rare that they command hundreds of dollars on the second-hand market?

That’s the situation [Mike Gardi] found himself in recently. Seeing that the educational games which helped put him on a long and rewarding career in software development are now nearly unobtainable, he decided to try his hand at recreating them on his 3D printer. With his keen eye for detail and personal love of these incredible toys, he’s preserved them in digital form for future generations to enjoy.

His replica of “The Amazing Dr. Nim” needed to get scaled-down a bit in order to fit on your average desktop 3D printer bed, but otherwise is a faithful reproduction of the original injection molded plastic computer. The biggest difference is that his smaller version uses 10 mm (3/8 inch) steel ball bearings instead of marbles to actuate the three flip-flops and play the ancient game of Nim.

[Mike] has also created a replica of “Think-a-Dot”, another game which makes use of mechanical flip-flops to change the color of eight dots on the front panel. By dropping marbles in the three holes along the top of the game, the player is able to change the color of the dots to create various patterns. The aim of the game is to find the fewest number of marbles required to recreate specific patterns as detailed in the manual.

Speaking of which, [Mike] has included scans of the manuals for both games, and says he personally took them to a local shop to have them professionally printed and bound as they would have been when the games were originally sold. As such, the experience of owning one of these classic “computer” games has now been fully digitized and is ready to be called into corporeal form on demand.

This is really a fascinating way of preserving physical objects, and we’re interested to see if it catches on with other toys and games which otherwise might be lost to time. As storage capacities get higher and our ability to digitize the world around us improve, we suspect more and more of our physical world will get “backed up” onto the Internet.