Hidden Pantry Compartment Opens With A Puzzle!

February 5, 2014 by 20 Comments

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What’s the number one thing kids always dream about for when they have their own house someday? Hidden passages? Revolving bookcases? Closets that lead to Narnia? Secret compartments? Well, [TracRat] has lived out at least one of those dreams by making his very own Myst inspired hidden pantry compartment!

His pantry is located under the stairs and to make use of the awkward space, he decided to build a wine rack. He still had a lot of unused space so he decided to take it a step further. He’s built a wooden puzzle combination lock consisting of four colored knobs that slide back and forth in grooves. When the correct combination is made, pressing on the square symbol at the top rolls the entire wine rack backwards, exposing a secret side cabinet. It’s an absolutely gorgeous piece of woodwork and we’re totally impressed by the perfect execution of it.

Do you love Myst too? Check out this awesome Myst inspired Myst(ery) box [Michael] made for his girlfriend’s birthday! Or how about a leather-bound Myst book that lets you play Myst on a computer inside of it!

Tic Tac PIC Pack: A Pocket Programmer

February 5, 2014 by 10 Comments

Sure, mint tin housings are great. But you have to defend against shorts, and cutting out holes for ports and buttons is dangerous business. [Daniel] prefers plastic, and he tipped us off about a PICKit2 clone that he designed to fit inside of a tic tac box.

Almost all of the components were salvaged except for the microcontroller and the connectors. He wound his own inductor using the ferrite core from a CFL. [Daniel] had to make a few improvisations for this project. He didn’t have a 20MHz crystal, so he used a 12MHz crystal and tweaked the fuse bits after burning the firmware.

To save space on the board, he soldered wires to RESET, VCC, GND, PGD, and PGC to program the firmware and then removed the wires. The only trouble he had with it was more or less easily solved by replacing two transistors.

You may remember that we linked to his USBasp programmer in a mentos container a few months back. We figure [Daniel] must have some pretty fresh breath.

Nimble Dodgebot Is Super Skittish

February 4, 2014 by 10 Comments

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For one of [Aron’s] recent robotics modules at college he was tasked with building a small robot. He decided to make project Dodgebot, a cute and extremely quick robot that won’t run into things!

The body is made of perforated steel and supports the motor boxes with wheels (stolen from a toy perhaps?), two IR sensors, and the tidy protoboard on top to contain the electronics — seriously check out the wiring on it!

To control it he’s using an 18-pin dsPIC30F3012 and a SN754410NE driver. The robot works by detecting different states based on the distance measurements from each sensor, and then varying the output to each motor. It’s extremely quick and quite fun to watch as it seems to dodge everything in its path! See for yourself, after the break. 

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WS2811 SPI Driver Using One Transistor And Passives

February 4, 2014 by 6 Comments

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We love the WS28xx projects because even if we never plan to use them, the signal timing is like the most addictive puzzle game ever. For instance, check out this WS2811A driver which uses hardware SPI to generate the signals.

The WS28xx offerings place a microcontroller inside an RGB LED, allowing them to be individually addressed in very long chains or large matrices (still a chain but different layout). But the timing scheme used to address them doesn’t play well with traditionally available microcontroller peripherals. [Brett] had been intrigued by some of the attempts to bend hardware SPI to the will of the WS2811 — notably [Cunning_Fellow’s] work featured in this post. He took it a great step forward by simplifying the driver to just one transistor, three resistors, and a capacitor.

Click through the link above for his step-by-step description of how the circuit works (it’s not worth re-explaining here as he does a very concise job himself). The oscilloscope above shows the SPI signal on top and the resulting timing signal below. You will notice the edges aren’t very clean, which requires the first pixel to be very close to the driver or risk further degradation. But, since the WS28xx drivers feature a repeater which cleans up signals like this, it’s smooth sailing after the first pixel.

 

Kitchen Computer Hides In Pantry Door

February 4, 2014 by 33 Comments

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You might look at the images above and think “oh neat” and then go about your business. But you’d be missing a great motorized hidden computer build. We simply must insist that you click on that link and look at all that went into it. Do it. DO. IT.

Still here? Okay, we’ll give you the gist and then you won’t be able to help yourself. First off, [Designforhire] built that door completely from scratch using skills that your average hacker wields. At first glance you’d think it was a retrofit or done with serious woodworking tools (quality table saw, router table, etc.). This actually started with a simple frame out of 2″x3″ pine studs. This is faced with Masonite which was affixed with glue and brads. From there the upper half was outfitted with a dry-erase panel, and trim pieces were added.

Now the hack really starts to get interesting. The opening for the monitor and the keyboard are both motorized. An old cordless drill (borked handle and dead battery) was cannibalized for its motor which is run using the two black switches just above the left corner of the monitor. When closed, a dry-erase calendar covers the monitor and a blank panel keeps the keyboard secret. The computer itself is actually in the basement, with cables running down the hinged side of the door and through a hole in the jamb.

We didn’t see a video showing off the build, but you can satisfy that craving by looking back at the Kitchen HAL installation from a few years back.

GPS For A Graphing Calculator

February 4, 2014 by 15 Comments

GPS [Chris], graphing calculator hacker extrordinaire, has seen a few of his projects show up on the front page of Hackaday, mostly involving builds that turn graphing calculators like the TI-84 Plus shown above into something that copies a few features from a smartphone. His latest build, a hardware GPS module attached to the TI-84 Plus, is yet another feather in his cap of awesome and impractical addition to a classic piece of hardware.

There were two major technical challenges behind adding GPS to a graphing calculator. The first of these was powering a GPS sensor. Many a calculator modder has put a lot of work into documenting the USB port on the 84 Plus, revealing it is a USB OTG port, capable of serving as a host or device. It also supplies 5V of power to just about anything, burning through batteries as a result.

The next challenge was reading the data coming off the GPS sensor at 4800bps.The TI-84 Plus series of calculators have a series of interrupts that can fire at fractions of the 15MHz clock. By setting the timer up to fire every 197 clock ticks and dividing again by 16, [Chris] can read data at 4758.9bps. It’s close enough to get most of the data, and the checksum included in the NMEA protocol allows the software to discard bad messages.

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Retrotechtacular: Bakelite Plastics

February 4, 2014 by 46 Comments

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[ColdTurkey] sent in a really great video for this week’s Retrotechtacular. It’s a half-hour promo reel about Bakelite Plastic. There is so much to enjoy about this film, but we’ve been overlooking it because the first six minutes or so consist of an uncomfortably fake interview between a “Chemist” and “Reporter”. They are standing so close to each other that it’s violating our personal space. But endure or skip ahead and the rest of the video is gold.

Bakelite is an early plastic, and putting yourself in the time period it’s very easy to see the miracle of these materials. The dentures being molded above are made out of phenol formaldehyde resin (to us that sounds like something you don’t stick in your mouth but what do we know?). The plastic pellets take on the shape of the mold when heated — we don’t know if this where the name comes from or if it’s a variation on the name of the chemist who discovered the material: [Dr. Leo Baekeland]. This was the first synthetic plastic, and came at just the right time as it was heavily adopted for use in the electronics and the automotive industry. Both of which were forging new ground at the time.

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