Camcorder Viewfinder Converted To Diminutive Vector Display

January 14, 2020 by Dan Maloney 26 Comments

We generally cast a skeptical eye at projects that claim some kind of superlative. If you go on about the “World’s Smallest” widget, the chances are pretty good that someone will point to a yet smaller version of the same thing. But in the case of what’s touted as “The world’s smallest vector monitor”, we’re willing to take that chance.

If you’ve seen any of [Arcade Jason]’s projects before, you’ll no doubt have noticed his abiding affection for vector displays. We’re OK with that; after all, many of the best machines from the Golden Age of arcade games such as Asteroids and Tempest were based on vector graphics. None so small as the current work, though, based as it is on the CRT from an old camcorder’s viewfinder. The tube appears to be about 3/4″ (19 mm) in diameter, and while it still had some of its original circuitry, the deflection coils had to be removed. In their place, [Jason] used a ferrite toroid with two windings, one for vertical and one for horizontal. Those were driven directly by a two-channel push-pull audio amplifier to make patterns on the screen. Skip to 15:30 in the video below to see the display playing [Jerobeam Fenderson]’s “Oscilloscope Music”.

As much as we’d love to see a tiny game of Battlezone played on the diminutive display, there’s only so much it can do. Maybe an analog version of this adorable digital oscilloscope would be possible?

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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.

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Achieving Zen The Arduino Way

December 25, 2018 by Dan Maloney 17 Comments

The purpose of a Zen garden, those stylized landscapes created by painstakingly placing rocks and raking gravel into perfect patterns, is the doing of the thing. Making sure every line is perfectly formed is no mean feat, and the concentration required to master it is the point of the whole thing. But who has time for that? Why not just build a robot to create the perfect Zen garden in miniature?

That was what [Tim Callinan] and his classmates did for a semester project, and the “ZenXY” sand plotter was the result. There isn’t a build log for the device per se, although the video below makes it plain how they went about this. The sand table itself is a plywood box whose bottom is layered with fine white sand and contains a single steel ball. Below the table is an X-Y gantry carrying a powerful magnet. A gShield riding on top of an Uno turns G code into slow, stately movement of the ball through the sand. The patterns are remarkably intricate, and while it might not be the same as mastering the body control needed to rake gravel with precision, watching the ball push the sand around is pretty Zen all by itself

This isn’t the first time we’ve seen someone try to automate a traditional Japanese practice. This tea ceremony robot comes to mind, and this nicely crafted sand table is very similar to the ZenXY.

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Bot Makes Etch A Sketch Art In One Continuous Line

September 28, 2018 by Dan Maloney 17 Comments

Introduced in 1960 for the princely sum of $2.99 ($25.00 today), Etch A Sketch was to become a standard issue item for the Baby Boomers’ toy box. As enchanting as the toy seems, it’s hard to see why it had staying power: it was hard for young fingers to twirl the knobs, diagonal lines and smooth curves required a concert pianist’s fine motor control, and whatever drawings we managed to make were erased at the slightest jostle of the tablet.

Intent on righting these wrongs, [Sunny Balasubramanian] not only motorized an Etch A Sketch, but he’s also given it a mind of its own in a way. For those unfamiliar with the toy, it’s basically a manual X-Y plotter that drags a stylus across the underside of a glass screen, scraping off a silver powder clinging to the glass to make dark lines. Replacing the knobs with steppers is straightforward, of course, but driving them is the trick. [Sunny] hooked his up to a Raspberry Pi and wrote some Python code to drive them. The Pi also accepts input image files and processes them for rendering through the plotter, first doing Canny edge detection in OpenCV, then plotting a single path through the largest collection of connected pixels in the image. From there it’s just a matter of spinning the motors to create surprisingly detailed images. Check out the short video below to see it in action.

It’s hardly the first automatic Etch A Sketch we’ve seen – here’s one that automates everything including the shake to erase the drawing. That one cheats a little though, in that it rasters across the screen like a CRT. We really like how this one just does a single path. Pretty clever.

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Smiling Robot Moves Without Wires

May 22, 2018 by Brian McEvoy 10 Comments

What could be cuter than a little robot that scuttles around its playpen and smiles all day? For the 2018 Hackaday prize [bobricius] is sharing his 2D Actuator for Micro Magnetic Robot. The name is not so cute, but it boasts a bill of materials under ten USD, so it should be perfect for educational use, which is why it is being created.

The double-layer circuit board hides six poles. Three poles run vertically, and three of them run horizontally. Each pole is analogous to a winding in a stepper motor. As the poles turn on, the magnetic shuttle moves to the nearest active pole. When the perpendicular windings activate, it becomes possible to lock that shuttle in place. As the windings activate in sequence, it becomes possible to move left/right and forward/back. The second video demonstrates this perfectly.

[bobricius] found inspiration from a scarier source, but wants us to know this is his creation, not a patent infringement. We are not lawyers.

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Motorized Stage Finesses The Microscopic World

May 19, 2018 by Dan Maloney 12 Comments

No matter how fine your fine motor skills may be, it’s really hard to manipulate anything on the stage of a microscope with any kind of accuracy. One jitter or caffeine-induced tremor means the feature of interest on the sample you’re looking at shoots off out of the field of view, and getting back to where you were is a tedious matter of trial and error.

Mechanical help on the microscope stage is nice, and electromechanical help is even better, but a DIY fully motorized microscope stage with complete motion control is the way to go for the serious microscopist on a budget. Granted, not too many people are in [fabiorinaldus]’ position of having a swell microscope like the Olympus IX50, and those that do probably work for an outfit that can afford all the bells and whistles. But this home-brew stage ticks off all the boxes on design and execution. The slide is moved across the stage in two dimensions with small NEMA-8 steppers and microstepping controllers connected to two linear drives that are almost completely 3D-printed. The final resolution on the drives is an insane 0.000027344 mm. An Arduino lives in the custom-built control box and a control pad with joystick, buttons, and an OLED display allow the stage to return to set positions of interest. It’s really quite a build.

We’ve featured a lot of microscope hacks before, most of them concerning the reflective inspection scopes we all seem to covet for SMD work. But that doesn’t mean we haven’t shown love for optical scopes before, and electron microscopes have popped up a time or two as well.

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Watch Video On A Oscilloscope With An ESP32

December 23, 2017 by Dan Maloney 18 Comments

[bitluni] got a brand new scope, and he couldn’t be happier. No, really — check the video below; he’s really happy. And to celebrate, he turned his scope into a vector display using an ESP32.

Using a scope in X-Y mode is nothing new, of course. The technique is used to display everything from Lissajous patterns from an SDR to bouncing balls from an analog computer. Taken on as more of an exercise to learn how to use his new tool than a practical project, [bitluni]’s project starts by using two DACs on an ESP32 to create simple Lissajous patterns to learn about the scope’s controls. Next he built some code to display 3D point clouds, but learned that the native DAC code wasn’t up to the job. A little hacking improved the speed 27-fold, which was enough for great 3D images and live video from an I²S camera module. The latter was accomplished by grabbing frames from the camera and rendering them pixel by pixel, CRT style. The results are pretty clean, and there’s a lot to be learned about both using scopes as X-Y displays and tweaking the ESP32 for maximum performance.

Need more background on the ESP32? Start by checking out these ESP32 tutorials.

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