FLASH.IT: The RGB LED Climbing Wall

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[Chris] and his friends were kicking around ideas for a Burning Man project, and this is the one that stuck: a rock climbing wall with RGB LEDs embedded in the holds. The holds themselves were custom made; the group started by making silicone molds of varying shapes and sizes, then added the electronics and poured in polyurethane resin to create the casting. The boards for these LEDs are equipped with a central hole that pairs up with a peg in the silicone mold. [Chris] also solved an annoying spinning problem by affixing a bolt to the far end of the LED board: once embedded in the polyurethane, the bolt provides resistance that the thin board cannot. The finished holds bolt onto the wall with all their wires neatly sticking out of the back to be hooked up to a central controller.

The Instrucables page suggests a few ways to get the lights working, including grabbing the nearest Arduino and relying on the Neopixel Library from Adafruit. [Chris] went the extra mile for Burning Man, however, designing Arduino-software-compatible controller boards capable of communicating via DMX, which expanded the system from a simple display to one capable of more complex lighting control. Stop by the Github for schematics and PCB layouts, and stick around for a video of the wall after the break. If the thrill-seeking outdoorsman inside you yearns for more, check out WALL-O-TRON from earlier this summer.

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Accurate Temperature Control Of Your 3D Printer Extruder

[Tim] is working on building a 3D printer and using it as an excuse to learn as much as he can. The first big issue he tackled was accurate temperature control, so he made an interesting write-up on how to characterize the thermal properties of an QU-BD extruder’s hot end and use that information to create a control algorithm for the heater.

The article starts with a basic thermal model and its corresponding formula. [Tim] then runs several tests where he measures the heater and extruder tip temperatures while switching on and off the heater. This allows him to figure out the several model parameters required to design his control algorithm. Finally, he tweaked his formula in order to predict the short term future so he can know when he should activate the heating element. As a result, his temperature is now accurately controlled in the 200°c +/-1°c window that he was shooting for.

Classic PDA Finds Second Life As A Network Touch Screen Display

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[Tomas Janco] had an old Casio Pocket Viewer PDA collecting dust. Rather than throw it away, He decided to re-purpose it as a display for time, weather, and the current status of his garage door.

The Casio Pocket Viewer was a competitor to the Palm Pilot. The two systems even shared the same LCD resolution – 160×160 monochrome. [Tomas’] particular model is an S660, sporting 6 megabytes of ram and an NEC V30MZ (Intel 8086 compatible) processor. Similar to Palm, Casio made an SDK freely available.

The SDK is still available from Casio, and [Tomas] was able to get it running on his PC. Development wasn’t without pitfalls though. The Pocket Viewer SDK was last updated in April of 2001. Software is written in C, but the then new C99 standard is not supported. The SDK does include a simulator and debugger, but it too is not as polished as todays systems – every simulator startup begins with setting the clock and calibrating the touch screen. Keep reading after the jump to learn about the rest of the hurdles he overcame to pull this one off.

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Seven Decade Programmable Resistor

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[Gerry Sweeney] was tired of messing around with resistors while prototyping his projects, so he decided he wanted a resistor decade box. The problem is they are typically big and rather expensive ($100+). Unhappy with the selection available for purchase, he decided to design his own.

In the accompanying video, he shows off his first attempt after being inspired by a past post we covered that used a combination of resistors and thumbwheel decimal switches. He modified the design a bit and used surface mount resistors instead, which made for a fairly compact and convenient seven decade resistor box. But he still wasn’t happy with it.

He decided to design his own PCB instead. The simple design utilizes surface mount resistors to conserve space, and jumpers to select the resistance. No bulky switches get in the way and it’s fairly cheap to produce.

Check out the great video explanation of the project after the break. He also shows off the insides of a commercial resistor decade box!

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RepRap Simpson Puts A New Spin On Delta RepRaps

Just when you think you’ve seen it all in the 3D printer world, something new pops up! [Nicholas Seward] posted a video of RepRap Simpson, his latest project.  Simpson is a delta robot – but unlike any delta we’ve seen before. Previous offerings vertical rails on which the arms travel. As you can see, this design mounts three articulated arms directly to the base of the printer, using steel cables as part of the joint mechanism.

Judging by [Nicholas’] posts on the RepRap forums, Simpson’s grounded delta design has already gone through a few revisions. The basic geometry though, has remained the same. [Nicholas] calls this edition a “Proportional Gear Drive Joint Simpson”. The name may not roll off the tongue, but the movements are incredibly smooth, organic, and fast.

As with any delta design inverse kinematics play a huge role in the software. [Nicholas] is trying to simplify this with an optical calibration system. For the adventurous, the equations are posted on the forums, and a python Gcode preprocessor is posted on Thingiverse.

Even Simpson’s base received special attention.  It’s built from a water jet cut piece of basalt.  We like the use of opposed helical gears on the large joints, as well as the guitar machine heads used to tension the cable drive. One thing we are not sure of is the longevity of system – will cable stretch play an issue? Will the printed parts suffer wear from the cables? Only time will tell.

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Functional NES Controller Coffee Table

For reddit user [the_masked_cabana], button mashing has taken on a whole new meaning.  His gigantic NES controller coffee table makes it hard to punch in the Konami code without breaking a sweat.

Even before discussing the electricals, this is one impressive build.  Each component was cut from multiple layers of MDF and assembled with screws, glue, and putty.  Once they were sanded smooth, he used layers of carefully applied Krylon paint to achieve a plastic sheen that is remarkably faithful to its 5″ counterpart.  For the more precise lettering, custom cut vinyl stickers did the trick.

Of course, looking the part is only half the battle.  Tearing apart an original NES controller, he soldered wires to the button connections and ran them to eight arcade style buttons located under the replica button covers.  A collection of bolts and springs keep everything aligned and produce the right kind of tactile feedback to the user.  A removable cable in the back provides the connection to the console.

If a four foot NES controller isn’t practical enough for you, he also added some storage space in the base and a removable glass cover that converts the controller into a coffee table.  For more details on the build, check out the reddit discussion.  You can also find an eerily similar working NES controller table in this geeky coffee table roundup from five years ago.

The Bitbox Console: An Open Source Gaming Rig

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A simple resistive DAC is all you need to drive a VGA display. Combining that with an on-chip DAC for audio, the STM32F405RGT6 looks like a good choice for a DIY game console. [Makapuf’s] Bitbox console is a single chip gaming machine based on the STM32 ARM processor.

We’ve seen some DIY consoles in the past. The Uzebox is a popular 8 bit open source game system, and [makapuf] was inspired by its design. His console’s use of a more powerful 32 bit processor will allow for more complex games. It will also provide more colors and higher quality audio.

One of the keys of the Uzebox’s success is the development tools around it. There’s a full emulator which allows for debugging with GDB. [Makapuf] has already built an SDL based emulator, and can debug the target remotely using GDB. This will certainly speed up game development.

After the break, check out a demo of the first game for the Bitbox: JUMP. Also be sure to read through [makapuf]’s blog for detailed information on the build.

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