Shark with Frickin’ LED Tells People not to Bother you

Everybody is busy these days, but sometimes it’s hard to tell. What with teleconferences being conducted over tiny Bluetooth headphones and Skype meetings where we seem to be dozing in front of the monitor, we’ve lost some of the visual cues that used to advertise our availability. So why not help your colleagues to know when to give you space with this shark themed WiFi-enabled meeting light?

Why a shark and not a mutated intemperate sea bass? Only [falldeaf] can answer that. But the particulars of the build are well-documented and pretty straightforward. A Photon runs the show, looking for an Outlook VFB file to parse. An RGB LED is used to change the color of the translucent 3D printed shark based on whether you’re in a meeting, about to step into one, or free. The case is 3D printed as well, although [falldeaf] farmed the prints out to a commercial printing outfit because of the size and intricacy of the parts. He did fabricate a nice looking wood base for the light, though.

There are plenty of ways to tell people to buzz off, but this is a pretty slick solution. For those in open floor plan workspaces, something like this IoT traffic light for you and your cube-mates might be in order.

Must-Have Overkill Christmas Tree Lights

The yuletide fire is out, so we’re starting to receive this year’s Christmas hacks. [Chris] sent us his awesome video-mapped tree lighting hack. His project made clever use of a bunch of cool tools, so even if you’re not thinking forward to next December, it’s worth a look. Still images don’t do it justice; check out the video below the break.

The end result is an addressable string of WS2812B LEDs connected up to a Raspberry Pi Zero that can display a video image even though it’s wrapped around a roughly cone-shaped (pine) object. But this is actually more impressive than you’d think at first; how would you map a flat image to a string of LEDs wrapped around a tree?

[Chris]’s solution was to write a routine that lit up the LEDs in a unique pattern and then detected them using OpenCV and a webcam, making the mapping directly. He then samples images from a video at exactly the points where the pixels are located on the tree, and sends this data out to the LEDs.

The basic framework here should transform fairly easily into a generic image-mapping procedure with randomly located LEDs, so we think it’s a hack that’ll outlast the season. And because it runs on the Pi Zero, everything is in Python so it’d be a good project for beginners to replicate. However, the code section on the project page still lists it as coming soon. We hope so!

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Parts bin Emergency Lights Deal with Tornado’s Aftermath

Sometimes having a deep inventory of parts in your shop is a pain – the clutter, the dust, the things you can’t rationally justify keeping but still can’t bear to part with. But sometimes the parts bin delivers and lets you cobble together some emergency lighting when a tornado knocks out your power.

It has been hard to avoid discussions of the weird weather in the US this winter. The eastern half of the country has had record warm temperatures, the west has been lashed by storms, and now December tornadoes have ripped through Texas and other parts of the south, with terrible loss of life and wide-ranging property damage. [TheTimmy] was close enough to one massive EF4 tornado to lose power on Saturday night, and after the charm of a candlelight Christmas evening wore off, he headed to the shop. He had a bunch of sealed lead acid batteries from old UPSs and a tangle of 12V LED modules, and with the help of some elastic bands and jumper clips he wired up a bunch of lights for around the house. Safer than candles by a long shot, and more omnidirectional than flashlights to boot.

The power came back before the batteries ran out of juice, so we don’t get to see any hacks for recharging batteries in a grid-down scenario. Still, it’s good to see how a deep parts bin and good mindset can make a positive impact on an uncomfortable situation. We’ve seen similar hacks before, like this hacked cordless tool battery pack or powering a TV with 18650 batteries. Be sure to share your story of epic power-outage hacks in the comments below.

Hackaday Explains: Li-Fi & Visible Light Communications

A new way to transmit data is coming that could radically change the way that devices talk to each other: LiFi. Short for Light Fidelity, LiFi uses visible light to send data, creating the link between router and device with invisible pulses of light. This type of Visible Light Communication (VLC) uses something that is present in pretty much every room: an LED lightbulb.

What is LiFi?

Li-Fi sounds like the an engineer’s fevered dream: it is fast, cheap, secure and simple to implement. Speeds of up to 10Gbps have been demonstrated in the lab, and products are now available that offer 10Mbps speed. It is cheap because it can use a modified LED lightbulb. It is secure because it only works where the light is visible: step out of the room and the signal is lost. It is simple to implement because it uses an existing technology: LEDs.

The basis of the technology is in turning the LED light on and off very fast. By switching an LED on and off millions of times a second, you can create a data signal that can be detected by a sensor, but which is invisible to the human eye. At the other end, another LED detects these pulses, and can send light pulses back in response, creating a bi-directional link. If you combine this with wired Ethernet or a WiFi network, you have an awesome combination: an Internet connection that uses visible light for the last link.

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Sudden Death Night Light Sounds Scary, Is Sweet

We have to admit that we were mislead by the title “Sudden Death: Wall Sign + Night Light”. This naturally conjured up images of deadly night lights, but the truth turned out to be a lot less fatal: [Smerfj] had two weeks to make a present for a friend’s wedding. The project was either a go or a no-go depending on the deadline — that sort of sudden death. But as we all know, deadlines have a way of bringing the motivation out of us that’s not always bad.

The night light in question is a bunch of hand-made circuits, each stuffed into a wooden slice with a letter burned on the face, spelling out [Smerfj]’s friend’s name. But to really appreciate it, you have to dig through the build details.

55461447189465844We didn’t know how to burn precise lettering into wood. [Smerfj] covered the wood in metal foil tape, then cut the letters out of the foil. Now applying the torch blackens only the part of the logs that have tape removed. Slick.

To get accurate lettering cut into the aluminum tape, [Smerfj] made an impromptu projector out of a cell phone taped to a chandelier (approximately a point light source) and a stencil suspended somewhere between the chandelier and the wood target. Naturally, this is best done in a darkened room under tight deadline pressure.

The battery holders are fantastic. Springs from commercial battery holders were soldered to enamel wire and placed in holes drilled just the width of AA batteries. With the length of the battery taken into account, channels were drilled into the wood and copper wires jammed through, holding the batteries in place, and providing the other electrical contact. Brilliant.

And finally, the free-form night light circuits are great. Fine-tuned to draw the minimum current, they’re adjusted to the specific LEDs and phototransistors that [Smerfj] had on hand. Bespoke free-form electronics in hand-blackened wood. That’s a nice gift.

Now [Smerfj] just needs nice packaging to present them in. We’re thinking DIY laser-cut boxes with interior lighting, naturally.

The LED Roundsystem

Gavin Morris has been working on his awesome sound responsive LED sculptures for a while. Technically the sculpture is an interesting application of WS2812 RGB LEDs, Raspberry Pis and a load of styrofoam cups and flower pots. However the artistic development, and inspiration for this project is equally interesting. Gavin shares his thoughts and a brief technical description of the project below.

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90,000 Lumen Flashlight Is Illuminating, Impractical and Blindingly Good

It may be better to light a single candle than to curse the darkness, but that was before [RCTestflight] came up with this: a 1000W LED flashlight that outputs about 90,000 lumens of light. That’s a lot: the best pocket LED flashlights output about 700 lumens.

[RCTestflight] built this monstrosity using ten 100-Watt LEDs, running off two RC car batteries. Each of the LEDs is connected to a sizable voltage converter and a very large heatsink that holds all of them in place. He says he gets about 8 minutes of light out of this thing, and that the heatsink gets warm after a minute or two of use. We’re not surprised: LEDs are more efficient than most other devices at converting electrical energy to light, but some always gets lost as heat.

Check out the video after the break. It’s very impressive, but this thing isn’t particularly practical as a handheld. It is big, heavy and is visible for miles. If you really want to light something up it does a great job (for a short period of time) due in part to the inclusion of a glass lens for each of the LEDs. This effectively focuses the beam on a properly distributed area. We wonder what would happen if all the beams were focused on one point? As long as you don’t cross the streams

We have covered a few more practical builds using similar LEDs, but this thing does have a certain outrageous charm, and could be useful for high-speed video, where the more light, the better.

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