THP Entry: A Theatrical Lighting Controller Powered By A Calculator

August 3, 2014 by 5 Comments

DMX

Theatrical lighting usually runs with the help of DMX, a protocol that’s basically MIDI for lights; small, lightweight, ancient, and able to run on the lowest spec computers imaginable. For his Hackaday Prize entry, [Alex] figured a regular ‘ol graphing calculator was sufficient to run a complete DMX controller, and with the help of an Arduino, figured out a way to do it.

The hardware for the system consists of a TI-84 graphing calculator, a few bits and bobs in the way of components, and an Arduino Pro Mini powered from the USB port on the calculator. The Arduino handles the transmitting of DMX packets at 250 kbaud using the DMXSimple library over a 5-pin XLR jack.

The software running on the calculator is where the novel part of the project begins. The software is designed to be extremely lightweight, sending packets to the Arduino using the 2-wire link cable. DMX Commands are wrapped up and transferred using the TI-83/84 link protocol, decoded on the Arduino, and sent out to the lighting rig.

While this probably won’t replace the multi-thousand dollar lighting consoles found in theatres, it’s still a very handy and portable tool for debugging lights. It’s also [Alex]’s My First Electronics Project™, and a pretty good one at that.

SpaceWrencherThe project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

Behold! The Most Insane Crowdfunding Campaign Ever

August 3, 2014 by 150 Comments

Hold on to your hats, because this is a good one. It’s a tale of disregarding the laws of physics, cancelled crowdfunding campaigns, and a menagerie of blogs who take press releases at face value.

Meet Silent Power (Google translation). It’s a remarkably small and fairly powerful miniature gaming computer being put together by a team in Germany. The specs are pretty good for a completely custom computer: an i7 4785T, GTX 760, 8GB of RAM and a 500GB SSD. Not a terrible machine for something that will eventually sell for about $930 USD, but what really puts this project in the limelight is the innovative cooling system and small size. The entire machine is only 16x10x7 cm, accented with a very interesting “copper foam” heat sink on top. Sounds pretty cool, huh? It does, until you start to think about the implementation a bit. Then it’s a descent into madness and a dark pit of despair.

There are a lot of things that are completely wrong with this project, and in true Hackaday fashion, we’re going to tear this one apart, figuring out why this project will never exist.

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Fixing A BASIC Calculator

August 3, 2014 by 26 Comments

HPThe early days of modern computing were downright weird, and the HP 9830B is a strange one indeed: it’s a gigantic calculator, running BASIC, on a CPU implemented over a dozen cards using discrete logic. In 2014 dollars, this calculator cost somewhere in the neighborhood of $50,000. [Mattis] runs a retrocomputer museum and recently acquired one of these ancient machines, and the walkthrough of what it took to get this old machine running is a great read.

There were several things wrong with this old computer when it arrived: the keyboard had both missing key caps and broken switches. The switches were made by Cherry, but no one at Cherry – or any of the mechanical keyboard forums around the Internet – have ever seen these switches. Luckily, the key cap connector isn’t that complex, and a little bit of bent wire brings the switches back up to spec. The key caps were replaced from a few collectors around the globe.

Getting as far as booting the machine, [Mattis] found some weirdness when using this old calculator: the result of 2+2 was 8.4444444, and 3+1 was 6.4444444. Simply pressing the number 0 and pressing execute resulted in 2 being displayed. With a little bit of guesswork, [Mattis] figured this was a problem with the ALU, and inspecting the ROM on that board proved to be correct: the first 128 nibbles of the ROM were what they were supposed to be, and the last 128 nibbles were the OR of the last half. A strange error, but something that could be fixed with a new replacement ROM.

After hunting down errors with the printer and the disk drive, [Mattis] eventually got this old calculator working again. For such an astonishingly complex piece of equipment, the errors were relatively easy to hunt down, once [Mattis] had the schematics for everything. You can’t say that about many machines only 10 years younger than this old calculator, but then again, they didn’t cost as much as a house.

Repurposed Laptop Batteries With A Twist

August 3, 2014 by 14 Comments

Arduino with lithium ion battery

Lithium ion batteries are becoming more and more common these days, but some of the larger capacity batteries can still carry a pretty hefty price tag. After finding Acer’s motherboard schematics online and doing a little reverse-engineering, [Tiziano] has found a way to reuse batteries from his dead laptop, not only saving the batteries from the landfill but also cutting costs on future projects.

These types of batteries have been used for many things in the past, but what makes this project different is that [Tiziano] is able to monitor the status of the batteries and charge them using I2C with an Arduino and a separate power supply, freeing the batteries from the bonds of the now-useless laptop.

With this level of communication between the microcontroller and the battery pack, there is little chance of the batteries catching on fire when they’re used in another project. Since the Arduino can also monitor the current amount of charge in the batteries, there is also a reduced risk that they will be damaged from under- or over-charging.

This wasn’t just as simple as hooking up the positive and negative leads of a power supply to the battery. [Tiziano] also had to model the internal resistance of the motherboard that the battery expects to see, and get the supply voltage just right so the battery’s safety protocols wouldn’t kick in to prevent them from charging. After a few other hurdles were jumped, [Tiziano] now has a large capacity lithium ion battery at his disposal for any future projects.

Hypno-Jellyfish Is Great For Kids (and Kids At Heart)

August 2, 2014 by 9 Comments

hjf3_blue

LED’s are fun. They are easily seen, not to hard to hook up, and produce a nice glow that can be gazed at for hours. Kids love them, so when [Jens] daughter was born, he knew that he wanted to create a device that would alternate colors depending on the object’s movement.

He utilized a mpu6050 accelerometer to detect changes in position, and wired together an Arduino Nano, a 9V battery, and a 12 LED neopixel ring from adafruit. Design requirements were jotted down beforehand ensuring that any child playing with the Hypno-Jellyfish would not be injured in any way. For example, anything that fits in a child’s mouth, will go in that child’s mouth; meaning that any materials used must be non-toxic, big enough not to be swallowed, and drool proof/water proof. The kids will pull, and throw, and drop the toy as well, so everything has to be of sturdy quality too. Epilepsy is also a concern when dealing with LED’s. But, [Jens] project hit the mark, making something that is kid-friendly while at the same time enjoyable for anyone else who likes color-changing lights.

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Finding And Repairing Microscopes From The Trash

August 2, 2014 by 24 Comments

scope We’re not quite sure where [Andy] hangs out, but he recently found a pile of broken microscopes in a dumpster. They’re old and obsolete microscopes made for biological specimens and not inspecting surface mount devices and electronic components, but the quality of the optics is outstanding and hey, free microscope.

There was a problem with these old scopes – the bulb used to illuminate specimens was made out of pure unobtainium, meaning [Andy] would have to rig up his own fix. The easiest way to do that? Some LEDs made for car headlights, of course.

The maker of these scopes did produce a few for export to be used in rural areas all across the globe. These models had a 12 Volt input to allow the use of a car battery to light the bulb. A LED headlight also runs off 12 Volts, so it was easy for [Andy] to choose a light source for this repair.

A little bit of dremeling later, and [Andy] had the new bulb in place. An off the shelf PWM controller can vary the brightness of the LED, controlled with the original Bakelite knob. The completed scope can easily inspect human hairs, the dust mites, blood cells, and just about anything down to the limits of optical microscopy. Future plans for this microscope might include another project on hackaday.io, a stage automator that will allow the imaging of huge fields at very high magnification – not bad for something pulled out of the trash.

Home Theater, Tribute To A Friend

August 2, 2014 by 12 Comments

The Greg Williams Theater

Ever since purchasing this house, [Ed] Always wanted a to turn his living room into a home theater, but not just any old projector and a white wall would do. He wanted the whole experience. [Ed] Started with a slightly damaged 12′ wide 4:3 roll up projector screen, he removed the damaged bottom portion and built a static frame to support the now 16:9 screen. Before he could mount the screen, he needed to drywall over a window that was inconveniently located. With the screen now in place, [Ed] framed out the elevated seating platform and steps with some 2×12 topped off with plywood. Next, the carpet that was sitting directly below the platform and steps was removed and then secured on top. Down firing LED fixtures were installed in the steps, to give them that movie theater look and feel. To provide the image, a refurbished HD projector acquired from the Bay of Electronics, was installed in the loft above the living room.

With the theater functional, [Ed] turned his attention to theater decorations. Dimmable ambiance lighting fixtures, using laser cut acrylic and CNC routed starboard (a marine-grade polymer), were made to resemble a film strip. Next a coffee table was crafted out of an equipment road case filled with movie props. Studio logos were painted on the sides with the use of laser cut stencils, and with a glass top, gives the illusion it came off the set of a hollywood movie. The addition of a rebuilt movie poster marquee, movie posters, candy stand, pop corn machine, and with the existing soda fountain and the arcade in the loft, the home theater was almost complete.

In a fitting tribute, [Ed] designed and built a marquee sign to dedicate and name the theater after his cousin Greg, one of his closest friends and avid movie watcher, who had sadly passed away. Video overview of all the hard work after the break.

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