AVR Minecraft Server Lets You Toggle Pins From The Virtual World

November 16, 2012 by Mike Szczys 21 Comments

Wanting to test his skills by building a webserver [Cnlohr] decided to also code a Minecraft server which allows him to toggle pins from inside the game. The rows of switches seen above give him direct access to the direction register and I/O pins of one port of the ATmega328.

The server hardware is shown in the image above. It’s hard to tell just from that image, but it’s actually a glass substrate which is [Cnlohr’s] specialty. He uses an ENC424J600 to handle the networking side of things. This chip costs almost twice as much as the microcontroller next to it. But even in single quantities the BOM came in at under $20 for the entire build.

In the video after the break [Cnlohr] and a friend demonstrate the ability for multiple users to log into the Minecraft world. The simulation is fairly bare-bones, but the ability to affect hardware from the game world is more exciting than just pushing 1s and 0s through some twisted pairs.

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Emulating A Student Clicker With An Arduino

November 16, 2012 by Brian Benchoff 20 Comments

When schools and universities have hundreds of students in a lecture course, they need a way to tell alumni and other potential benefactors that faculty/student relations are just as good as they were in the 1960s, when enrollment was just a fraction of current levels. Technology solves all problems, apparently, so administrators of these universities turn to ‘clickers’ – radio frequency remotes used to take attendance and administer quizzes.These clickers have absolutely no security, so it’s no surprise [Taylor Killian] was able to emulate one of these clickers with an Arduino allowing anyone with a laptop to cheat on a quiz, or have an entire class show up with only one student in the room.

Previously [Travis Goodspeed] (thanks for sending this in, [Travis]) tore apart one of these clickers – a TurningPoint ResponseCard RF – and discovered it uses a Nordic nRF24L01 wireless transceiver, commonly available on eBay for about two dollars.

[Taylor] connected this wireless module to an Arduino and whipped up a bit of code that allows him to listen to the audience responses, respond to a question as either a single clicker or all clickers, automatically respond with the most popular answer, and even block all audience responses to each question.

Perhaps technology doesn’t solve every problem, but at least [Taylor] learned something from a glorified remote control sold at the bookstore at an insane markup.

Porsche 911 Made Electric

November 16, 2012 by Brian Benchoff 63 Comments

[Kurt] wanted an electric car, and always wanted to drive a Porsche. Killing two birds with one stone, he decided to combine these wishes and convert a 2002 Porsche 911 into an electric vehicle.

After removing the engine, fuel tank, exhaust, radiator, and all the other things that make an internal combustion engine work, [Kurt] installed a high power motor, controller and 72 lithium phosphate batteries weighing in at over 500 pounds. He’s put over 300 miles on the car in the last few months while working out the kinks, but now he’s finally gotten the bugs out of the system allowing him to take it up to some relatively high speeds.

Already [Kurt] has taken his new ride to 100 mph and done a little bit of range testing that told him he should expect around 40 miles per charge in his new ride. It’s not exactly what he hoped, but more than enough for a few trips around town while riding in style.

After the break is a video [Kurt]’s first test drive of his electric Porsche.

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Google Books Team Open Sources Their Book Scanner

November 16, 2012 by Brian Benchoff 39 Comments

It’s no secret that Google has been scanning hundreds of thousands of books in the hope of recreating the Library of Alexandria. Publishers and authors really didn’t like that idea, so the Google books team is doing the next best thing: they’re releasing the plans for a very clever book scanner in the hope others will pick up the torch of creating a digital library of every book ever written.

Unlike some other book scanners we’ve seen that rely on an operator manually flipping pages, this linear book scanner turns the pages automatically with the help of a vacuum cleaner and a cleverly designed sheet metal structure after passing them over two image sensors taken from a desktop scanner.

The bill of materials comes in at around $1500, but according to the official design documents this includes a very expensive scanner, something that could be replaced in true hacker style with a few salvaged flatbed scanners.

After the break you can check out a Google Tech Talk presented by [Dany Qumsiyeh] going over the design and function of his DIY book scanner. There’s also a relatively thorough design document over on a Google code page.

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Hackaday Links: November 15, 2012

November 15, 2012 by Mike Szczys 14 Comments

Another way to break out dual pin headers

[Uwe] wrote in to share his technique for breaking out dual pin headers. He uses two single pin headers, a piece of protoboard, and a dual row pin socket to make an adapter. This is removable where the other method we saw this week was not.

Web-based slide show hack

Wanting to use an old Android tablet as a digital picture frame, [Gordon] coded up a simple way to use an HTML page to scan your picture directories to feed a rotating background image.

The simplest hot plate

For his chemistry experiments [Charlie] is using a plain old clothes iron for a hot plate. he simply clamps it upside down to the bench. It doesn’t have any stirring abilities, but we already have an old iron in the shop which we use for toner transfer so we’ll have to keep this in mind if we ever need to heat chemicals (might be a good way to warm etchant).

A charging VU meter

This Cambrionix series8 universal charger has columns of LEDs that are animated when a device is charging. [Steve Tyson] works for the company and has had some fun messing with the firmware. He’s showing off the display as a VU meter.

Game Boy knockoff teardown

This wide-form-factor Game Boy is a knockoff from way back when the original system hit the market. You won’t want to miss this lengthy post that takes a look at what’s inside. [Thanks Neil]

In-depth Comparison At STM32 F3 And F4 Discovery Boards

November 15, 2012 by Mike Szczys 5 Comments

The STM32 F3 and F4 Discovery boards have been around for a while now. We’ve looked at both separately and they’re impressive dev boards for the price. Now can get a closer look at each from this in-depth comparison of the two Cortex-M4 development tools.

To start off, both of the boards have the same size and footprint (there are two dual-row pin headers which break out the connections to the ARM chip). Fundamentally the F3 and F4 chips have a different level of features, but the boards themselves are aimed at different applications as well. The F3 series of microcontrollers looks to be more affordable than the F4, containing less program memory, no Ethernet capability, and only one USB port. But both have hardware floating-point abilities and they’re blazing fast. The boards offer a MEMS accelerometer for prototyping. But the Discovery-F3 also contains a gyroscope while the Discovery-F4 provides audio hardware like a microphone, and DAC.

If you want to use a Linux box to develop with these tools you might find this guide helpful.

Roomba And Virtual Walls Make Up This Theme Family Halloween Costume

November 15, 2012 by Mike Szczys 7 Comments

It figures. You spend a ton of time making a cool set of costumes and then you can’t get your kid to pose for a picture. It’s okay though, we still get the point. This themed set of costumes dresses the little one as a Roomba vacuuming robot while mom and dad are suited up as virtual walls (modules that are used to keep the bot from falling down stairs, etc.). It’s fun and unique, but had it not been for some additional electronics this would have been relegated to a links post. For safety sake each costume was outfitted with a ring of LEDs. As a challenge, the lights were given the ability to sync up patterns with each other.

Each costume has a circular frame at the top with a set of RGB LED strings attached. To get them to display synchronized patterns an IR transmitter/receiver board was designed and ordered from OSHPark. Each costume has four of these modules so no matter where the wearers are facing it should not break communications. A demo of the synchronized light rings can be seen after the break

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