DIY Studio Lights To Improve Your Videos

September 25, 2018 by Lewin Day 22 Comments

It’s 2018, a full thirteen years since YouTube was founded. With an online sharing service up and running, and high-resolution cameras in just about every mobile phone, the production of video has been democratized. Sadly, for those citizens with eyes, the production of good video is not so widespread. What’s one thing you need for good video? Good lighting – and you can build it yourself.

This build from [DIY Perks] relies upon readily available components and uses simple build techniques accessible to the average maker. Using cheap LED strips (albeit photography-grade ones), along with off-the-shelf plastics and dimmer modules, it’s possible to build a light that preserves colour integrity while being lightweight, compact, and easy to use. The final product is remarkably elegant – at a glance it could be a commercial product. Nifty tricks like daisy chaining the power supplies and combining different spectrum LEDs for better control add to the functionality.

Overall, it’s a build that does take some time, but it could easily be completed in a weekend and the results are top notch. It’s not the first lightbox build we’ve seen here, either. Video after the break.

[Thanks to Keith O for the tip!]

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World’s Smallest LED Blinky

September 23, 2018 by Mike Szczys 21 Comments

[Mike Harrison] is known for incredibly tiny soldering. Now he’s claiming a “world’s smallest” in the form of a stand-alone LED blinker, and we think he’s got the record.

He brought it along with him to Friday’s Beagleboard Bring-a-Hack, and we got a close look at the diminutive assembly. The project was dreamed up when [Mike] saw an announcement from Seiko about a new supercapacitor in a tiny package (likely the CPH3225A giving the blinky a footprint of 3.2 x 2.5 mm). With that in hand he added a PIC 10f322 microcontroller in a SOT23 package, an 0603 smoothing capacitor, and an SMD LED.

Blinky net to a metric ruler

US Quarter for scale (ruler is metric)

Charging jig doubles as a carrying case

With such a tiny package, the trickiest part is figuring out how to charge that supercap. [Mike] used a drill and hand files to make a square hole in a CR2032 battery holder to serve as a jig. The bottom of the supercap rests against the battery as a pogo pin makes the second connection to a terminal on the side of his assembly. It charges quickly and will happily blink away for about six minutes after charging.

Mike set out to make two of these, but dropped the second supercap when at his workbench to be forever lost in the detritus common to every electronics workshop. When he first pulled it out at the meetup we were on a rooftop terrace and we were more than a bit concerned that this would just blow away. How do you begin to fabricate such a tiny assembly? He used UV cured epoxy to glue them together first, then somehow completed the soldering by hand!

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Unphotogenic Lighting As A Feature

September 12, 2018 by Brian McEvoy 13 Comments

Have you ever taken a picture indoors and had unsightly black bars interrupt your otherwise gorgeous photo? They are caused by lighting which flickers in and out in its normal operation. Some people can sense it easier than others without a camera. The inconsistent light goes out so briefly that we usually cannot perceive it but run-of-the-mill camera phones scan rows of pixels in sequence, and if there are no photons to detect while some rows are scanned, those black bars are the result. Annoying, right?

What if someone dressed that bug of light up as a feature? Instead of ruining good photos, researchers at the University of California-San Diego and the University of Wisconsin-Madison have found out what different frequencies of flicker will do to a photograph. They have also experimented with cycling through red, green, and blue to give the effect of a poorly dubbed VHS.

There are ways an intelligent photographer could get around the photo-ruining effect with any smartphone. Meanwhile DSLR cameras are already immune and it won’t work in sunlight, so we are not talking about high security image protection. The neat thing is that this should be easy to replicate with some RGB strips and a controller. This exploits the row scanning of new cameras, so some older cameras are immune.

Less Is More: A Micromatrix Display In A Square Inch

September 12, 2018 by Al Williams 7 Comments

In your living room, the big display is what you want. But in an embedded project, often less is more. We think [bobricius] will agree since he submitted a tiny 4×5 LED display into our square inch challenge. The board features an ATtiny CPU and twenty SMD LEDs in a nice grid. You can see them in action, scrolling to some disco music in the video below.

There is plenty of room left in the CPU for bigger text strings — the flash memory is just over 10% full. A little side-mounted header makes it easy to program the chip if you want to change anything.

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Monitoring blinking LED for home power usage

Monitoring Power By Counting Blinks

September 5, 2018 by Steven Dufresne 14 Comments

What do you do when you want to add a new feature to some electronics but you can’t or don’t want to tear into the guts? You look for something external with which you can interface. We like these hacks because they take some thinking outside the box, literally and figuratively, and often involve an Aha! moment.

[Simon Aubury’s] big household load was electric heating and his ancient heaters didn’t provide any way to monitor their usage. His power meters weren’t smart meters and he didn’t want to open them up. But the power meters did have an external LED which blinked each time 1 Wh was consumed. Aha! He could monitor the blinks.

Home power usage graph — Maximum is white, average is orange, and minimum is blue.

Doing so was simple enough. Just point photoresistors at the two meter’s LEDs and connect them and capacitors to a Raspberry Pi’s GPIO pins. Every time a pulse is detected, his Python code increments the LED’s counter and every fifteen minutes he writes the counters to an SQL database. Analysing his data he saw that nothing much happens before 5 AM and that the lowest daytime usage is around noon. The maximum recorded value was due to a heater accidentally being left on and the minimum is due to a mini holiday. Pretty good info given that all he had to go on was a blinking light.

Where else are there LED indicators which you can tap into? Here’s an only slightly more invasive usage where a washing machine’s “end of cycle” LED was removed and the power going to it was rerouted to an Arduino for remote monitoring.

When Are Dumb LEDs The Smart Choice?

September 4, 2018 by Kerry Scharfglass 25 Comments

A couple years ago I got into making electronic conferences badges by building a device for DEFCON 25 shaped like a dragonfly. Like all badges the most important design factor was quite literally how flashy it was, and two years ago I delivered on that with ten RGB LEDs. At the time I planned to hand-assemble each and every of the 105 badges at my kitchen table. Given those constraints, and a desire for electrical and programmatic simplicity, I landed on using APA102s (DotStar’s in Adafruit parlance) in the common 5050 sized package. They were easy to place, easy to design with electrically, simple to control, and friendly to a human pick-n-place machine. Though by the end of the production run I had discovered a few problems, the APA102s were a success.

This year I made a new and improved version of the dragonfly, but applying my lessons learned led me to choose a very different LED architecture than 2017. I swapped out the smart LEDs for dumb ones.

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The Quest For High Powered Blinky And Buzzing

September 3, 2018 by Brian Benchoff 3 Comments

Sometimes, we need devices to notify us of something. The oven timer is going off. Your phone has a push notification. The smoke detector battery is getting low. All of these problems can be solved with a buzzer or an LED. It’s a simple and cheap problem to solve.

But what if you need to know if something’s wrong with a diesel engine that throwing out 90 dB of noise? What if you’re not guaranteed to be around that engine? What if you need to tell everyone within a half mile that something is wrong. Again, LEDs and beepers, but the standard, off-the-shelf implementation isn’t going to cut it. You need massive amounts of buzzers and LEDs, and you’re going to need to drive them all with some reasonably high current. How do you solve that problem?

This is the problem [Tegwyn] had to solve for another one of his Hackaday Prize entries. The solution is what you would expect — buzzers and LEDs — but he’s putting some serious current behind these devices. There are, in fact, thermal considerations taken into account when you’re beeping this many buzzers.

The LEDs for this project are a handful of blindingly bright 1209 and 1206 SMD parts, and the buzzer is an obnoxiously loud SMD 97 dB buzzer. There are eight buzzers on this board. So, how do you drive these power-hungry devices? [Tegwyn] is using an L293E half-bridge motor driver, in a ‘Power-DIP’ package for relatively effective heat dissipation. Does it work? Oh, yes, and it’s very annoying. Take a look at the video below and judge for yourself. You can, indeed, make something louder and more annoying by adding more power.

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