TightLight: A 3D Projection Mapping Assistant

tightLight

Anyone can grab a projector, plug it in, and fire a movie at the wall. If, however, you want to add some depth to your work–both metaphorical and physical–you’d better start projection mapping. Intricate surfaces like these slabs of styrofoam are excellent candidates for a stunning display, but not without introducing additional complexity to your setup. [Grady] hopes to alleviate some tedium with the TightLight (Warning: “music”).

The video shows the entire mapping process of which the Arduino plays a specific role toward the end. Before tackling any projector calibration, [Grady] needs an accurate 3D model of the projection surface, and boy does it look complicated. Good thing he has a NextEngine 3D laser scanner, which you’ll see lighting the surface red as it cruises along.

Enter the TightLight: essentially 20 CdS photocells hooked up to a Duemilanove, each of which is placed at a previously-marked point on the 3D surface. A quick calibration scan scrolls light from the projector across the X then Y axis, hitting each sensor to determine its exact position. [Grady] then merges the photocell location data with the earlier 3D model using the TouchDesigner platform, and bam: everything lines up and plays nice.

Twitter Knitter Combines 40 Year Old Hardware With Modern Social Media

When presented with a vintage Empisal Knitmaster knitting machine, members of the TOG Dublin Hackerspace worked together to not only bring it back from the dead but to also add some custom hardware that allows for computer generated patterns.

At first the Knitmaster was in fairly bad shape requiring a few custom machined parts just to function.  It was originally designed to feed in special punch cards that mechanically directed the many moving parts of the machine (called “dibblers”) to knit patterns in yarn.  Using an Arduino, a number of servos, and a microswitch to detect when the knitting carriage is pulled across, this card-read system was replaced with a computer controlled mechanism that can direct the machine to print out images one row at a time.

Of course, you don’t get too many opportunities to name your project something as cute as “The Twitter Knitter”, so once the system was working, it was only a matter of writing some code to snatch tweets from the web and generate images out of the text.  Visitors of the Dublin Mini Maker Faire got to watch it in action as they posted tweets with a particular hashtag which the machine happily printed in yarn (as long as they weren’t too long).

Video demo after the jump.

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Building An Entire Pinball Machine From Just The Playfield

It all started  when [Iancole] bought a Fireball Home edition playfield on some famous auction website for $135. Originally, he had the intent of lighting the lamps with an Arduino, framing it, and hanging it on the wall of his office — which often happens with old pinball parts. But then his boys asked if he “could make it play”.

[Iancole] managed to find the pinball schematics online and started designing the electronics required by the many LEDs, solenoids and switches. As the LEDs and switches are on the same matrix, he chose a simple Arduino to cycle through them, giving the player the impression that the lights are constantly on. [Iancole] originally planned on using his raspberry Pi to control the solenoids, but he later switched to another Arduino because of the precise timing required.

Therefore, his Pi was used as the heart of the machine. It is interfaced to the two Arduinos to read states and send commands while running the game program, displaying HD graphics on a 24″ screen, playing music and game event sounds. All the electronics are proudly displayed on the backbox, and many developments are planned for it. Also, the machine will be on display at the Orlando Mini Maker Faire on October 5th!

Rescuing An SD Card With An Arduino

A few days ago, one of [Severin]’s SD cards died on him, Instead of trashing the card, he decided to investigate what was actually wrong with the card and ended up recovering most of the data using an Arduino and an immense amount of cleverness.

SD cards can be accessed with two modes. The first is the SDIO mode, which is what cameras, laptops, and other card readers use. The second mode is SPI mode. SPI is slower, but much, much simpler. It turned out the SDIO mode on [Severin]’s card was broken, but accessing it with an Arduino and SPI mode worked. There was finally hope to get files off this damaged card.

[Severin] used a few sketches to dump the data on the SD card to his computer. The first looked at the file system and grabbed a list of files contained on the card. The second iterated over the file system and output all the files in hex over the serial port. With a bit of Python, [Severin] was able to reconstruct a few files that were previously lost forever.

Even though the SD card was completely inaccessible with a normal card reader, [Severin] was able to get a few files off the card. All the sketches and Python scripts are available on the Githubs, ready to recover files from your broken SD cards.

Liquid Nitrogen (finally) Makes An Arduino Project Cool

At $1.5 a liter in Moscow, [Michail] couldn’t resist buying some liquid nitrogen for himself. He thought that because Arduinos were quite popular among geeks, he’d try to overclock one while bringing its temperature down to -196°C/-320°F.

To check the ATmega was still working correctly, [Michail] designed several stability tests: SRAM read/write, flash read, arithmetic math and program flow tests (code with some conditionals). He used a standard HD44780 LCD to view the tests results but also an LED, blinking the number of the test it would have failed. The Arduino was externally clocked by a TTL-logic based square signal generator he designed, which can produce a clock between 16 and 100MHz. It turns out that you can run an Arduino at 65.3MHz when it is cooled with liquid nitrogen!

[Michail]’s article also explains what happens to the different on-board components when cooled with LN2: electrolytic capacitors becomes virtually non-existent, X7R capacitors’ impedance drop by 2/3, silicon diodes voltage drop increase by 50% and LED’s colors change. Check out the video below:

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Reactive Target Range For Nerf, Airsoft, Etc.

reactive-target-range

Taking the time to build a reactive target range really adds to the fun of toy weapons. It lets you move beyond just point and shoot to actual games of skill.

The project is anchored by an Arduino board. It connects to a piezo element on the back of each of these sheet metal targets. Detecting when a projectile hits the target works pretty much the exact same way the ever popular Knock-block works. To provide interactive enjoyment each target has an LED which, when lit, indicates that the target is active. From here it’s just a matter of coding to add different challenges. So far [Viktor Criterion] has implemented quick draw, timed, and rapid fire modes. The demo after the break shows off everything, including the slick modular design he came up with to make the system portable.

We’d love to see these targets mounted on motorized tracks. Each round would have the targets moving closer to you at a faster pace to keep you on your toes.

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Hacking Sensoria, The Smart Sock

sensorSock

Sensor-meets-sock product “Sensoria” won’t hit the shelves for a while, but [Andrew] managed to snag a Sensoria Gaming SDK and has hacked the smart sock to control an inexpensive toy helicopter. Seldom do we see projects this rugged yet clearly effective. The sock sends data via its companion device—a Bluetooth anklet—to LabVIEW. LabVIEW subsequently talks to an attached Arduino to manipulate a servo that [Andrew] just…duct taped to the helicopter’s controller. The result: a a quick and dirty hack that proves surprisingly intuitive, providing accelerator-style foot control to drive the throttle. Check out a video of [Andrew] punishing his helicopter after the break.

This is the first hack we’ve seen for the Sensoria, which is still in the crowdsourcing phase over at Indigogo. They have already reached their funding goal, but a few SDKs remain unclaimed. You can watch an official video of the sock’s sensors lighting up a heat map in real time below.

And, if you missed it, have a look at the AsTeRICS project’s helicopter controlled by neck muscles.

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