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.

Building A Lightweight Softbox For Better Photography

March 13, 2018 by Brian Benchoff 14 Comments

If you want to take good photographs, you need good light. Luckily for us, you can get reels and reels of LEDs from China for pennies, power supplies are ubiquitous, and anyone can solder up a few LED strips. The missing piece of the puzzle is a good enclosure for all these LEDs, and a light diffuser.

[Eric Strebel] recently needed a softbox for some product shots, and came up with this very cheap, very good lighting solution. It’s made from aluminum so it should handle the rigors of photography, and it’s absolutely loaded with LEDs to get all that light on the subject.

The metal enclosure for this softbox is constructed from sheet aluminum that’s about 22 gauge, and folded on a brake press. This is just about the simplest project you can make with a brake and a sheet of metal, with the tabs of the enclosure held together with epoxy. The mounting for this box is simply magnets super glued to the back meant to attach to a track lighting fixture. The 5000 K LED strips are held onto the box with 3M Super 77 spray adhesive, and with that the only thing left to do is wire up all the LED strips in series.

But without some sort of diffuser, this is really only a metal box with some LEDs thrown into the mix. To get an even cast of light on his subject, [Eric] is using drawing vellum attached to the metal frame with white glue. The results are fairly striking, and this is an exceptionally light and sturdy softbox for photography.

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How To Control The Lights With A TV Remote

February 16, 2018 by Lewin Day 16 Comments

In this day and age of the Internet of Things and controlling appliances over the internet, the idea of using an old-fashioned television remote to do anything feels distinctly 2005. That doesn’t mean it’s not a valid way to control the lights at home, and [Atakan] is here to show us how it’s done.

To the experienced electronics maker, this is yesterday’s jam, but [Atakan] goes to great lengths to hash out the whole process from start to finish, from building the circuitry to switch the lights through to the code necessary to make a PIC do your bidding. It’s rare to see such a project done with a non-Arduino platform, but rest assured, such things do exist. There’s even some SPICE simulation thrown in for good measure, if you really want to get down to the nitty-gritty.

Perhaps the only thing missing from the writeup is a primer on how to execute the project safely, given that it’s used with a direct connection to live mains wiring. We’d love to hear in the comments about any changes or modifications that would be necessary to ensure this project doesn’t hurt anyone or burn an apartment complex down. Sometimes you can switch lights without a direct connection to the mains, however – like this project that interfaces mechanically with a standard light switch.

ESP32 Makes Not-So-Smart Lights Smart

January 11, 2018 by Will Sweatman 24 Comments

Long taken for granted – lights are a basic necessity of modern life. From the time of the first light bulb, we’ve been able to navigate the dark without the use of fire. With the advent of the Internet of Things, it has become somewhat of a requirement to bring a little intelligence to lights before labeling yourself as a hardware hacker. There are many ways to do this; one of the most common being making use of an ESP32. [Luca Dentella] is somewhat of an ESP32 expert, and has written a fantastic tutorial on how to use the chip. The tutorial builds up to making a set of lights controllable from a smartphone web browser as well a light intensity sensor.

Now before you brush this off as simple n0Ob stuff – consider the following. He’s using a Lolin32 lite dev board, a BH1750 light intensity sensor and a relay to interface with mains for the lights. He wrote his own firmware and gets into the gritty details of developing the HTTP interface and flashing code to the correct memory.

We’ve seen a lot of ESP32 projects here at Hackaday, including this most interesting clock. Be sure to check out the video below to see the smart lights in action.

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Aluminum Foil Heatsink Keeps LEDs In Check

December 20, 2017 by Tom Nardi 24 Comments

In your kitchen is very likely a roll of aluminum foil, like most people you probably use it to line pans or wrap food for baking. If you heard somebody used aluminum foil in the cooling of items, you could be forgiven for thinking they were referring to wrapping leftovers and tossing them in the refrigerator. But rather than preserving Mom’s famous meatloaf, [Michael Dunn] is using that classic kitchen staple to protect his LED strips.

Cheap LED strips are becoming extremely popular and have been popping up in more and more projects, but they have a pretty serious flaw: heat dissipation. Left on their own they can get hot enough to cook themselves, which is sort of a problem when you’re looking to replace as much of your home lighting with them like [Michael] is.

Heat was of particular concern as he was looking to retrofit a delicate shade with his beloved LED strips. Since he wanted a column of LEDs inside the unique shape of the shade, he reasoned that some kind of heat-conductive tubular structure could be used as both a mandrel to wrap the LEDs around and a way to dissipate heat. Like most of us, his first thought was copper pipe. But unfortunately the only copper pipe he had handy was of too small a diameter.

The tube of foil on the other hand was the perfect diameter, and while aluminum isn’t as good a conductor of heat as copper, it’s certainly no slouch either. Early tests weren’t that great when the tube was laying on the bench, but once it stood vertically convection got the air moving and cooled the LEDs down to where [Michael] was comfortable enough to put them inside the shade. Though he does have some lingering doubts about leaving the cardboard tube in such a toasty environment.

Going back through the archives, we’ve seen some absolutely fantastic projects utilizing LED strips in the past, some of which have come up with their own creative ways of beating the heat.

Resurrecting Dead LED Lightbulbs

December 19, 2017 by Tom Nardi 29 Comments

If you’ve gone down the lighting isle of a store recently, you’ve no doubt noticed we are firmly in the age of the LED light bulb. Incandescent bulbs are kept in small stock for those who still have the odd-ball use case, there’s usually a handful of CFL bulbs for those who don’t mind filling their house with explosive vials of hot mercury, but mostly its all LED now. Which is as it should be: LED lighting is clearly the superior choice in terms of energy efficiency, lifetime, and environmental impact.

Unfortunately, a lot of the LED bulbs you’ll see on the rack are of pretty poor quality. In an effort to drive cost down corners get cut, and bulbs which should run for decades end up blowing after a couple of months. After yet another one failed on him, [Kerry Wong] decided to do a teardown to examine the failure in detail.

He notes that most of the LEDs seem to fail in the same way, flickering after they are switched on until they just stop lighting up entirely. This hints at an overheating issue, and [Kerry] opines that aesthetic and cost considerations have pushed heat dissipation to the back burner in terms of design. It also doesn’t help that many of these bulbs are sitting in insulated recessed fixtures in the ceiling, making it even harder to keep them cool.

Once he separates the actual LEDs from the driver circuitry, he is able to determine that the emitters themselves still work fine. Rather than toss the whole thing in the trash, it’s possible to reuse the LEDs with a new power source, which is quickly demonstrated by showing off a shop light he built from “dead” LED light bulbs.

[Kerry Wong] isn’t the only one to put his LED bulbs under the knife. We’ve covered a number of teardowns which explore the cutting edge of home lighting; for better or for worse.

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Rocking Playmobil Wedding

October 4, 2017 by Brian McEvoy 6 Comments

Many of us have put our making/hacking/building skills to use as a favor for our friends and family. [Boris Werner] is no different, he set about creating a music festival stage with Playmobil figures and parts for a couple of friends who were getting married. The miniature performers are 1/24 scale models of the forming family. The bride and groom are on guitar and vocals while junior drums.

Turning children’s toys into a wedding-worthy gift isn’t easy but the level of detail [Boris Werner] used is something we can all learn from. The video after the break does a great job of showing just how many cool synchronized lighting features can be crammed into a tiny stage in the flavor of a real show and often using genuine Playmobil parts. Automation was a mix of MOSFET controlled LEDs for the stage lighting, addressable light rings behind the curtain, a disco ball with a stepper motor and music, all controlled by an Arduino.

Unless you are some kind of Playmobil purist, this is way cooler than anything straight out of the box. This is the first mention of Playmobil on Hackaday but miniatures are hardly a new subject like this similarly scaled space sedan.

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