Measuring The Lifespan Of LEGO

April 19, 2013 by Mike Szczys 34 Comments

lifespan-of-LEGO

How many times can you put two LEGO pieces together and take them apart again before they wear out? The answer is 37,112. At least that’s the number established by one test case. [Phillipe Cantin] was interested in this peculiar question so he built the test rig above to measure a LEGO’s lifespan.

The hacked together apparatus is pretty ingenious. It uses two servo motors for testing, each driven by the Arduino which is logging the count on an SD card. One of the two white LEGO parts has been screwed onto an arm of the upper servo. That servo presses down onto the mating piece which is sitting inside that yellow band. Look close and you’ll realize the yellow is the handle end of an IC puller. When the post on the lower servo is moved toward one arm of the puller it grips the lower LEGO piece tightly so that the upper servo can pull the two apart. In addition to the assembly and disassembly step there’s a verification step which raises the mated parts so that a reflectance sensor can verify that they’re holding together. [Phillipe] let the rig run for ten days straight before the pieces failed.

Don’t miss his video description of the project after the break.

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Hacked Interactive R2D2 Controlled By Raspberry Pi

March 23, 2013 by Ryan Fitzpatrick 2 Comments

hacked-R2D2-controlled-by-raspberry-pi

Ah R2D2. Probably one of the most recognized little robots on the planet. There have to be a hundred different toys of R2 out there, but one of the more impressive is the 30th Anniversary Interactive edition. Complete with all kinds of bells and whistles, it’s about as realistic as they come. One Star Wars fan found himself in possession of a broken Interactive R2, and with his girlfriend’s birthday coming up, decided to do a little droid surgery to create the ultimate gift.

Giving Anakin a run for his money, all the controls for this R2 unit were custom built. A Raspberry Pi running Rasbian acts as the brain. Facial recognition was implemented using OpenCV. Voice commands in either English or Chinese were made possible by PocketSphinx. Some of the other features he included are: message recording and playback, ultrasonic distance detection, motion detection, wifi, and a rechargeable battery. Many of those features were included in the original toy, but since this unit was broken, had to be rebuilt from scratch.

In the end, it must have impressed his girlfriend – she’s now his wife. Good work Jedi. Check out some build photos and a video demonstration after the break.

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Futaba 10C Radio Modified For Spektrum Module Compatibility

March 21, 2013 by Ryan Fitzpatrick 4 Comments

futaba-radio-modified-to-fly-spektrum

The Futaba 10C radio (non-module version) is [Tom]’s transmitter of choice. Unfortunately, it isn’t compatible with the Spektrum DSM2 technology modules he wanted to use. So, being the crafty guy he is, he decided to hack it so it was.

Upon opening the Futaba transmitter, he realized that the non-module version of the 10C didn’t really seem that different than a module version. His transmitter just has a pcb hardwired in place where the modules would otherwise go. He soldered a 4 conductor audio jack to the unused pins on the pcb in the transmitter, then mounted it in the case with some J.B. Weld. He then wired and mounted the receiving jack in the module case. A small 6 inch audio cable bridges the two devices, and velcro holds them neatly together.

He discovered that certain modules have problems with the channels being out of order. Unless someone comes up with a firmware hack, there’s no way to remap the controls. So, some modules are just not compatible. [Tom] gives a very nice video walkthrough after the break. Check it out.

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DIY Arduino Pro Mini Quadcopter

March 19, 2013 by Ryan Fitzpatrick 5 Comments

[execUc] took a stock V929 quadcopter and started making some crafty customizations. The main change – the control electronics were replaced by an Arduino Pro Mini (16Mhz model). He soldered all the modules on a prototyping board and, although admittedly a bit heavy, the little guy takes flight with no problem.

Among other details, an HMC5883L (magnetometer) and MPU6050 (accelerometer / gyroscope) are used as sensors. A LiPo 7.4V battery pack supplies the power. The brushed motors are controlled by pulse-width modulation from SI2302 MOSFET with added diodes. He plans to swap out the micro-controller for an ARM7 stm32F103 for extra computing power, and needs to play with the PID values to correct a slight problem he seems to be having when rotating.

Check out a test flight video after the break. [execUc] has a thorough list of all the alterations he made in the video description, so be sure to read it.

[via Hacked Gadgets]

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Sonic Screwdriver Meets TV-B-Gone

March 16, 2013 by Brian Benchoff 35 Comments

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[furrysalamander] has a friend that is a really big Doctor Who fan. It happens that this friend has a birthday coming up, and [furrysalamander] wanted to get her something amazing. A Sonic Screwdriver is always a great gift, but [furrysalamander] wanted to put his personal touch on it. He ended up adding a TV-B-Gone to [10]’s screwdriver, turning a fictional deus ex machina into a functional device.

The body of the Sonic comes from this replica of [10]’s screwdriver from Think Geek. Inside, the screwdriver has space for a battery a circuit board to control the lights and sound normally expected of a sonic screwdriver. [furrysalamander] added a freeform circuit composed of an ATtiny85, a transistor, LED, and a few resistors to add the ability to turn just about any TV off.

Of course [furrysalamander] needed to program the ATtiny with the TV-B-Gone firmware, and lacking any AVR development tools he used a Raspberry Pi’s GPIO pins to write the firmware to the microcontroller. That’s something we’ve seen before, but [furrysalamander] is a champ for including the process in his Instructable.

The end result is a Sonic Screwdriver that doesn’t work on wood and can’t break a deadlock seal. It turns off TVs just fine, though, and looks great to boot. You can check out a demo of [furrysalamander]’s sonic in action after the break.

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Launching A Glider From Space

March 10, 2013 by Mike Szczys 45 Comments

We get a ton of tips about weather balloon launches taking hobby electronics into space. But every once in a while one of them stands out from the rest. This project does send an electronic payload into space, but it also lets [David] fly his hardware back from near-space using an RC airplane.

The return vehicle is unpowered, but that shouldn’t be a problem as launching from a weather balloon will provide plenty of altitude for the flight. Because the temperature experienced in that part of the atmosphere is so cold [David] had to take several things into account. Obviously you want your batteries and control electronics to be insulated from the cold. But something that doesn’t usually pop into mind are issues with the servo motors which run the glider’s flaps. They usually have some white grease on the gears. At temps as low as -50C that grease will harden and make the servo stop working so he made sure to clean the gears thoroughly before the flight.

Unfortunately [David] had several problems capturing images and recorded video from the ground station. But his write up is still a fun read and the clip after the break gives a general overview of the entire project from the nose camera of the glider.

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Virtual Archery Game Makes Practicing Convenient, Safe, And Inexpensive

March 2, 2013 by Ryan Fitzpatrick 13 Comments

Inspired by playing The Legend of Zelda video game series, Cornell University students [Mohamed Abdellatif] and [Michael Ross] created a Virtual Archery game as their ECE 4760 Final Project. The game consists of a bow equipped with virtual arrows and a target placed about 20 ft away. The player has three rounds to get as high of a score as possible. A small display monitor shows the instructions, and an image of where the shot actually hit on the target.

Pressing a button on the front of the bow readies a virtual arrow. A stretch sensor communicates with a microcontroller to determine when the bow string has been drawn and released. When the bow is drawn, a line of LEDs lights up to simulate a notched arrow. The player aims, and factors in for gravity. An accelerometer calculates the orientation of the bow when fired. The calculated shot is then shown on the display monitor along with your score.

This immediately makes me think of Laser Tag, and feels like a product that could easily be mass marketed. I’m surprised it hasn’t been already. Good work guys.

[via Hackedgadgets]

Check out the video demonstration after the break:

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