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1347 Articles

Raspberry Pi-Powered Back To The Future Time Circuits

November 10, 2015 by 13 Comments

Here’s something that’s a little late to celebrate the fact that all the events in Back to the Future have happened in the past, but that’s what time machines are for, right? [Deater] created Pi-powered time circuits and a flux capacitor. He might not have a DeLorean, but he does have the equipment to turn a DeLorean into a cool car.

The ‘time circuits’ shown on-screen in Back to the Future actually weren’t very complex; the times were just cutouts with lights and gels; no real electronics wizardry necessary. Of course the BttF DeLorean has since been remodeled and refurbished with time circuits that look and act the part, and [Deater]’s time circuits have everything you would expect: a display of the destination, current, and last time, sound effects, numeric keypad, flux capacitor, and a speedometer.

While it doesn’t simulate the time circuits from the movie exactly, that’s not necessarily a bad thing. The movie time circuits were colored gels, and wouldn’t exactly be practical for a Raspberry Pi-based prop. It’s a great build, and one that would look great in either a ’98 Nissan Altima or a DeLorean

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Three Watt Individually Addressable RGB LEDs

November 6, 2015 by 32 Comments

While the gold standard for colorful blinky projects are individually controllable RGB LEDs, the usual offerings aren’t really that impressive. Yes, a few hundred Neopixels, WS2812, or other RGB LEDs will sear your retinas, but what if you wanted blinky glowy stuff that is so over the top as to be an affront to whatever creator you believe in?

This is it. [Ytai Ben-Tsvi] created an individually addressable RGB LED called the Pixie that is perfect for all the times when you need something bright, colorful, and want to blind a few people in the process.

WS2812s and Neopixels are basically RGB LEDs with a small microcontroller tucked tucked away inside, and so far there is no design house or fab plant in China that is crazy enough to add one of these tiny dies to an already overpowered LED. To build the Pixie, [Ytai] took a bare RGB LED module and added a microcontroller – a PIC12FF157X in this case. It’s not exactly a powerful microcontroller, but it can handle the shift register-like function of an individually addressable RGB, and adds gamma correction, over heating protection (something necessary when you’re dumping this much power into a tiny board, and other safeguards for each individual LED.

[Ytai] is working with Adafruit to produce these Pixies, and although they’re rather expensive at $15 per LED, you won’t need very many to blind yourself.

Tiny PIC Clock Is Not A Tiny Bomb

October 13, 2015 by 100 Comments

It’s been a few weeks since the incident where Ahmed Mohamed, a student, had one of his inventions mistaken for a bomb by his school and the police, despite the device clearly being a clock. We asked for submissions of all of your clock builds to show our support for Ahmed, and the latest one is the tiniest yet but still has all of the features of a full-sized clock (none of which is explosions).

[Markus]’s tiny clock uses a PIC24 which is a small yet powerful chip. The timekeeping is done on an RTCC peripheral, and the clock’s seven segment displays are temporarily lit when the user presses a button. Since the LEDs aren’t on all the time, and the PIC only consumes a few microamps on standby, the clock can go for years on a single charge of the small lithium-ion battery in the back. There’s also a phototransistor which dims the display in the dark, and a white LED which could be used as a small flashlight in a pinch. If these features and the build technique look familiar it’s because of [Markus’] tiny MSP430 clock which he was showing around last year.

Both of his tiny clocks are quite impressive for their size, features, and power consumption. Some of the other clocks we’ve featured recently include robot clocks, clocks for social good, and clocks that are not just clocks (but still won’t explode). We’re suckers for a good clock project here, so keep sending them in!

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Halloween Hood Has Hideous LED Gaze

October 8, 2015 by 12 Comments

Looking to create fear and dread with your Halloween costume? [Becky Stern] over at Adafruit has you covered, with her tutorial on building a mystical hood with LED eyes, perfect for your next Jawa, Black Mage, or Orko costume.

This creepy-looking creation is based around a Gemma controller driving two NeoPixel Jewels, small circular RGB LED boards. The Gemma drives the boards to slowly fade on and off for the required creepy eye effect, but it would be easy to create other lighting patterns.

Speaking of patterns, the tutorial also includes a sewing pattern for the hood, and plans for a 3D printed battery holder that would make the whole thing very easy to carry. If the eyes aren’t enough, how about adding an LED magic staff to complete your creepy ensemble? Or perhaps some light-up dinosaur spiky plates?

Do you have any good Halloween costume hack plans? Let us know in the comments, and we’ll put together a list of the best closer to the hideous day.

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Doubling Down On A Big LED Display

October 4, 2015 by 16 Comments

Last year at the 2014 NC Maker Faire, Manical Labs brought a large LED display. Blinking LEDs and pixel animations are always welcome, but at 24 inches square this build was impressive, but it wasn’t impressive enough. This year, [Adam] at Manacal Labs wanted to go bigger. Much bigger. This build is called Colossus, and at two square meters and with 1250 individual LEDs, this LED display is a colossal build.

When building a big LED display, an enormous amount of planning pays off in dividends. The backbone of this project is a sheet of 3/8″ plywood, ripped down to 1 meter by 2 meters. 1250 half-inch holes are drilled in this sheet over four or five very long and very tedious evenings. The LEDs are installed in the thousand or so holes, and a grid of foam core board encases each individual LED.

One of the biggest problems with large arrays of LEDs is the sheer scale of it all. If one LED pixel draws 60mA, 1250 pixels means a draw of 75 Amps. This current will melt most wires, so the power is delivered over custom made copper bus bars. Driving this display with a reasonable refresh rate is another important consideration; WS2812 lights, with an 800kHz signal over one wire, is far too slow for a huge display. Instead of the 2812s, [Adam] went with LPD8806 LEDs that can be clocked at 30MHz. This is controlled with two AllPixels, effectively making this two displays acting as one. It all comes together in a very big LED display. You can check out a video of it below.

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A Thousand LED Lights For Your Room

October 3, 2015 by 18 Comments

Sure, you could get a regular light fixture like a normal person… Or you could use close to a thousand RGB LEDs to light your room!

That’s what [Dmitry] decided to do after trying to figure out the best way to light his pad. You see, his room is 4 by 4 meters, and WS2812 RGB LED strips happen to come in 4 meter lengths… Coincidence? We think not.

The problem with using 16 meters of LED strips is powering them… You see, at 16 meters, you’re looking at about 5V @ 57.6A — and we’re guessing you probably don’t have a 5V 60A power supply handy. Not to mention if you run them in series, the resistance of the system is going to kill your efficiency and the last LEDs probably won’t even work… So [Dmitry] had to break the system up. He has two power supplies feeding the strips from the middle of each pair — that way, he doesn’t have to worry about any voltage drops due to the length of the strips.

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Because Burning Man Needed More LEDs

October 1, 2015 by 10 Comments

There are a lot of blinky glowy things at Burning Man every year, and [Mark] decided he would literally throw his hat into the ring. He built a high visibility top hat studded with more RGB LEDs than common sense would dictate. It’s a flashy hat, and a very good example of the fashion statement a few hundred LEDs can make.

[Mark]’s top hat has 481 WS2812b addressable LEDs studded around the perimeter, a common LED choice for bright and blinky wearables. These LEDs are driven by a Teensy 3.1, with a Bluetooth transceiver, a GPS module, a compass, and gyro/accelerometer attached to the microcontroller. That’s a lot of hardware, but it gives [Mark] the capability of having the hat react to its own orientation, point itself North, and allow for control via a modified Nintendo NES controller.

The WS2812 LEDs draw a lot of power, and for any wearable project having portable power is a chief concern. [Mark]’s original plan was to use an 8x battery holder for the electronics enclosure, and use five AA batteries to power the hat. The total idle draw of the LEDs was 4.5 Watts, and with even a few LEDs blinking colors there was a significant voltage drop. The idea of powering the hat with AA batteries was discarded and the power source was changed to a 195 Watt-hour lithium ion battery bank that was topped off each day with a solar panel.

The hat is awesome, exceedingly bright, and something that gets a lot of attention everywhere  it goes. For indoor use, it might be too bright, but this could be fixed with the addition of a bit of black stretchy fabric, like what our own [Mike Szczys] did for his DEF CON hat. [Mark]’s hat is just version 1, and he plans on making a second LED hat for next year.