The Lichtspiel: Not A Simple Child’s Toy.

April 3, 2018 by James Hobson 9 Comments

For his niece’s second birthday, [Stefan] wondered what a toddler would enjoy the most? As it turns out, a box packed with lights, dials and other gadgets to engage and entertain.

For little Alma’s enjoyment, three potentionmeters control a central LED, a row of buttons toggle a paired row of more lights, a rotary encoder to scroll the light pattern of said row left and right, and some sockets to plug a cable into for further lighting effects. Quite a lot to handle, so [Stefan] whipped up a prototype using an Arduino — although he went with an ATmega 328 for the final project — building each part of the project on separate boards and connected with ribbon cables to make any future modifications easier.

[Stefan] attempted to integrate a battery — keeping the Lichtspiel untethered for ease of use — and including a standby feature to preserve battery life. A power bank seemed like a good option to meet the LED’s needed 5V, but whenever the Lichtspiel switched to standby, the power bank would shut off entirely — necessitating the removal of the front plate to disconnect and reconnect the battery every time. The simpler solution was to scrap the idea entirely and use the charging port as a power port instead — much to the delight of his niece who apparently loves plugging it in.

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A Gif-Playing Top Hat For FRC 2018!

April 3, 2018 by James Hobson 13 Comments

In gearing up to mentor a team at the 2018 FIRST Robotics Competition, redditor [dd0626] wanted to do something cool that resonated with this year’s 8-bit gaming theme. Over the course of a few days, they transformed a top hat into a thematically encapsulating marquee: a LED matrix display loaded with gifs!

The display is actually a sleeve — made from shipping foam, a pillow case, and an old t-shirt — that fits over the hat, leaving it intact and wearable for future events. A Teensy3.6 displays the gifs on four WS2812 16×16 RGB LED matrices, and while a sheer black fabric diffuses the light, it’s still best viewed from several feet away. This is decidedly not intended to be a stealthy hat display.

To mitigate current draw, [dd0626] is using a 5V 30A DC/DC converter and keeping the brightness at a minimum — otherwise, each panel can pull up to 15A! To offset any dip in performance, they’ve bundled in a massive 22,400mAh, 24V battery pack to keep the hat running for a while. Despite all the hardware, the hat weighs under two pounds — eminently wearable for a long day of competition. Continue reading “A Gif-Playing Top Hat For FRC 2018!” →

Pavement Projection Provides Better Bicycle Visibility At Night

April 2, 2018 by Dan Maloney 67 Comments

Few would question the health benefits of ditching the car in favor of a bicycle ride to work — it’s good for the body, and it can be a refreshing relief from rat race commuting. But it’s not without its perils, especially when one works late and returns after dark. Most car versus bicycle accidents occur in the early evening, and most are attributed to drivers just not seeing cyclists in the waning light of day.

To decrease his odds of becoming a statistics and increase his time on two wheels, [Dave Schneider] decided to build a better bike light. Concerned mainly with getting clipped from the rear, and having discounted the commercially available rear-mounted blinkenlights and wheel-mounted persistence of vision displays as insufficiently visible, [Dave] looked for ways to give drivers as many cues as possible. Noticing that his POV light cast a nice ground effect, he came up with a pavement projecting display using four flashlights. The red LED lights are arranged to flash onto the roadway in sequence, using the bike’s motion to sweep out a sort of POV “bumper” to guide motorists around the bike. The flashlight batteries were replaced with wooden plugs wired to the Li-ion battery pack and DC-DC converter in the saddle bag, with an Arduino tasked with the flashing duty.

The picture above shows a long exposure of the lights in action, and it looks very effective. We can’t help but think of ways to improve this: perhaps one flashlight with a servo-controlled mirror? Or variable flashing frequency based on speed? Maybe moving the pavement projection up front for a head-down display would be a nice addition too.

There’s More To MIDI Than Music – How About A Light Show?

March 31, 2018 by Sven Gregori 6 Comments

MIDI instruments and controllers are fun devices if you want to combine your interest in music and electronics in a single project. Breaking music down into standardized, digital signals can technically turn anything with a button or a sensor into a musical instrument or effect pedal. On the other hand, the receiving end of the MIDI signal is mostly overlooked.

[FuseBerry], a music connoisseur with a background in electronics and computer science, always wanted to build a custom MIDI device, but instead of an instrument, he ended up with a MIDI controlled light show in the shape of an exploded truncated icosahedron ([FuseBerry]’s effort to look up that name shouldn’t go unnoticed). He designed and 3D-printed all the individual geometric shapes, and painstakingly equipped them with LEDs from a WS2818B strip. An Arduino Uno controls those LEDS, and receives the MIDI signals through a regular 5-pin DIN MIDI connector that is attached to the Arduino’s UART interface.

The LEDs are mapped to pre-defined MIDI notes, so whenever one of them is played, and their NoteOn message is received, the LEDs light up accordingly. [FuseBerry] uses his go-to DAW to create the light patterns, but any software / device that can send MIDI messages should do the trick. In the project’s current state, the light pattern needs to be created manually, but with some adjustments to the Arduino code, that could be more automated, something along the lines of this MIDI controlled Christmas light show.

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Color Spaces: The Model At The End Of The Rainbow

March 30, 2018 by Kerry Scharfglass 23 Comments

When I learned about colors in grade school everything started with red, yellow, and blue and getting fancier colors was easy. I mixed some blue into my yellow to get green, or into red to get purple, and so on. After painting enough terrifying “art” for my parents, this made intuitive sense. That is until my mind was blown by the revelation that this wasn’t always true!

To make the same colors with light instead of paint I had to use red, green, and blue, not yellow. It was until much later when trying harness banks of RGB LEDs that this knowledge became useful. I was struggling to make my rogue diodes look quite the way I wanted when I stumbled into the realization that maybe there was another approach. What did the numbers representing R G and B actually mean? Why those parameters? Could there be others? [Elliot Williams] has written about the importance of gamma correction and adjustment for human perception of color, but we can ask a more fundamental question. Why do we represent color this way at all?

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An LED Effect For Every Occasion

March 28, 2018 by Kerry Scharfglass 13 Comments

Quality software development examples can be hard to come by. Sure, it’s easy to pop over to Google and find a <code> block with all the right keywords, but having everything correctly explained can be hit or miss. And the more niche the subject, the thinner the forum posts get. Bucking the downward trend [HansLuijten] provides an astoundingly thorough set of LED strip patterns in his comprehensive post titled Arduino LED strip effects.

Don’t let the unassuming title lead you astray from the content, because what’s on offer goes beyond your average beginner tutorial on how to setup a strand of NeoPixels. [HansLuijten] is thorough to a fault; providing examples for everything from simple single color fades and classic Cylon eyes to effects that look like meteors falling from the sky. Seriously! Check out the videos on their webpage. Those chasing lights you see around theater signs? Check. Color twinkle and sparkle? Check. Color wipes and rainbow fades? Check, and check. Continue reading “An LED Effect For Every Occasion” →

It’s A Nixie! It’s A VFD! No, It’s A Custom LED Display In A Tube

March 26, 2018 by Dan Maloney 42 Comments

Like the look of Nixies but they just seem a little overdone? Or perhaps you just don’t want the hassles of a high-voltage power supply? Then maybe these faux-Nixie LED “tube” displays will find a way into your next clock build.

For his 2018 Hackaday Prize entry, [bobricius] decided that what the world needs is a Nixie that’s not a Nixie. To that end, each display is formed by seven surface-mount LEDs soldered to a seven-segment shaped PCB and slipped into a glass tube. The LEDs are in 4014 packages so they’re only 4 millimeters long, but what they lack in size they make up for in brightness. We’re not sure if it’s a trick of the camera, but the LEDs certainly seem to put off a bluish glow that’s reminiscent of vacuum-fluorescent displays — it’s like a Nixie and a VFD all rolled up in one package. The current case, which hides the clock circuitry on the lower part of the PCB, is just plastic, but this would look spiffy in a fine wooden case.

Could this be another Nixie tube killer that never was? Perhaps, but wherever it ends up, we like the look of it, and we’re glad it’s one of the early Hackaday Prize entries. Have you got something to enter in the greatest hardware competition on Earth? If not, get cracking!