A drone is shown hovering in the sky, with two bright lights shining from its underside.

2025 Component Abuse Challenge: Overdriven LEDs Outshine The Sun

November 6, 2025 by Aaron Beckendorf 13 Comments

Tagging wildlife is never straightforward in the best of times, but it becomes a great deal more complicated when you’re trying to track flying insects. Instead of trying to use a sensor package, [DeepSOIC] attached tiny, light retroreflectors to bees and hornets, then used a pulsed infrared light mounted on a drone to illuminate them. Two infrared cameras on the drone track the bright dot that indicates the insect, letting the drone follow it. To get a spot bright enough to track in full sunlight, though, [DeepSOIC] had to drive some infrared LEDs well above their rated tolerances.

The LEDs manage to survive because they only fire in 15-µs pulses at 100 Hz, in synchrony with the frame rate of the cameras, rather like some welding cameras. The driver circuit is very simple, just a MOSFET switch driven by an external pulse source, a capacitor to steady the supply voltage, and a current-limiting resistor doing so little limiting that it could probably be removed. LEDs can indeed survive high-current pulses, so this might not really seem like component abuse, but the 5-6 amps used here are well beyond the rated pulse current of 3 amps for the original SFH4715AS LEDs. After proving the concept, [DeepSOIC] switched to 940 nm LEDs, which provide more contrast because the atmosphere absorbs more sunlight around this wavelength. These new LEDs were rated for 5A, so they weren’t being driven so far out of spec, but in tests they did survive current up to 10A.

We’ve seen a similar principle used to drive laser diodes in very high-power pulses a few times before. For an opposite approach to putting every last bit of current through an LED, check out this low-power safety light.

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2025 Pet Hacks Challenge : Poopopticon Is All Up In Kitty’s Business

May 29, 2025 by Tyler August 6 Comments

After seeing this project, we can say that [James] must be a top-tier roommate. He has two flatmates– one human, one feline, and the feline flatmate’s litterbox was located in a bathroom close to the other human’s room. The odors were bothersome. A bad roommate might simply say that wasn’t their problem, but not [James].

Instead, he proclaimed “I shall build a poopopticon to alert me so I may clean the litterbox immediately, before smells can even begin to occur, thus preserving domestic harmony!”* We should all aspire to be more like [James].

It was, admittedly, a fairly simple project. Rather than dive into feline facial recognition, since it only has to detect a single cat, [James] used a simple IR sensor out of his parts bin, the sort you see on line-following robots. The microcontroller, an ESP8266, also came from his parts bin, making this project eligible for the ‘lowest budget’ award, if the contest had one.

The ESP8266 is set to send a message to a waiting webhook. In this case it is linked to a previous project, a smart ‘ring light’ [James] uses to monitor his Twitch chats. He’s also considered hooking it up to his lazy-esp32-banner for a big scrolling ‘change the litterbox!’ message. Since it’s just a webhook, the sky is the limit. Either way, the signal gets to its recipient and the litter gets changed before it smells, ensuring domestic bliss at [James]’ flat. If only all our roommates had been more like [James], we’d be much less misanthropic today.

He did not, in fact, say that.

The host stands in his electronics lab with the image of four remote controls overlaid.

Introducing Infrared Remote Control Protocols

April 13, 2025 by John Elliot V 23 Comments

Over on his YouTube channel [Electronic Wizard] has released a video that explains how infrared (IR) remote controllers work: IR Remote Controllers protocol: 101 to advanced.

This video covers the NEC family of protocols, which are widely used in typical consumer IR remote control devices, and explains how the 38 kHz carrier wave is used to encode a binary signal. [Electronic Wizard] uses his Rigol DS1102 oscilloscope and a breadboard jig to sniff the signal from an example IR controller.

There is also an honorable mention of the HS0038 integrated-circuit which can interpret the light waves and output a digital signal. Of course if you’re a tough guy you don’t need no stinkin’ integrated-circuit IR receiver implementation because you can build your own!

Before the video concludes there is a brief discussion about how to interpret the binary signal using a combination of long and short pulses. If this looks similar to Morse Code to you that’s because it is similar to Morse Code! But not entirely the same, as you will learn if you watch the video!

Flashlight shining through gold leaf on glass

Shining Through: Germanium And Gold Leaf Transparency

January 5, 2025 by Heidi Ulrich 26 Comments

Germanium. It might sound like just another periodic table entry (number 32, to be exact), but in the world of infrared light, it’s anything but ordinary. A recent video by [The Action Lab] dives into the fascinating property of germanium being transparent to infrared light. This might sound like sci-fi jargon, but it’s a real phenomenon that can be easily demonstrated with nothing more than a flashlight and a germanium coin. If you want to see how that looks, watch the video on how it’s done.

The fun doesn’t stop at germanium. In experiments, thin layers of gold—yes, the real deal—allowed visible light to shine through, provided the metal was reduced to a thickness of 100 nanometers (or: gold leaf). These hacks reveal something incredible: light interacts with materials in ways we don’t normally observe.

For instance, infrared light, with its lower energy, can pass through germanium, while visible light cannot. And while solid gold might seem impenetrable, its ultra-thin form becomes translucent, demonstrating the delicate dance of electromagnetic waves and electrons.

The implications of these discoveries aren’t just academic. From infrared cameras to optics used in space exploration, understanding these interactions has unlocked breakthroughs in technology. Has this article inspired you to craft something new? Or have you explored an effect similar to this? Let us know in the comments!

We usually take our germanium in the form of a diode. Or, maybe, a transistor.

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Lock-In Thermography On A Cheap IR Camera

October 28, 2024 by Dan Maloney 17 Comments

Seeing the unseen is one of the great things about using an infrared (IR) camera, and even the cheap-ish ones that plug into a smartphone can dramatically improve your hardware debugging game. But even fancy and expensive IR cameras have their limits, and may miss subtle temperature changes that indicate a problem. Luckily, there’s a trick that improves the thermal resolution of even the lowliest IR camera, and all it takes is a little tweak to the device under test and some simple math.

According to [Dmytro], “lock-in thermography” is so simple that his exploration of the topic was just a side quest in a larger project that delved into the innards of a Xinfrared Xtherm II T2S+ camera. The idea is to periodically modulate the heat produced by the device under test, typically by ramping the power supply voltage up and down. IR images are taken in synch with the modulation, with each frame having a sine and cosine scaling factor applied to each pixel. The frames are averaged together over an integration period to create both in-phase and out-of-phase images, which can reveal thermal details that were previously unseen.

With some primary literature in hand, [Dmytro] cobbled together some simple code to automate the entire lock-in process. His first test subject was a de-capped AD9042 ADC, with power to the chip modulated by a MOSFET attached to a Raspberry Pi Pico. Integrating the images over just ten seconds provided remarkably detailed images of the die of the chip, far more detailed than the live view. He also pointed the camera at the Pico itself, programmed it to blink the LED slowly, and was clearly able to see heating in the LED and onboard DC-DC converter.

The potential of lock-in thermography for die-level debugging is pretty exciting, especially given how accessible it seems to be. The process reminds us a little of other “seeing the unseeable” techniques, like those neat acoustic cameras that make diagnosing machine vibrations easier, or even measuring blood pressure by watching the subtle change in color of someone’s skin as the capillaries fill.

DIY Laser Tag Project Does It In Style

October 26, 2024 by Donald Papp 21 Comments

This DIY lasertag project designed by [Nii], which he brought to Tokyo Maker Faire back in September, is a treasure trove. It’s all in Japanese and you’ll need to visit X (formerly Twitter) to see it, but the images do a fine job of getting the essentials across and your favorite translator tool will do a fair job of the rest.

There’s a whole lot to admire in this project. The swing-out transparent OLED display is super slick, the electronics are housed on a single PCB, the back half of the grip is in fact a portable USB power bank that slots directly in to provide power, and there’s a really smart use of a short RGB LED strip for effects.

The optical elements show some inspired design, as well. An infrared LED points forward, and with the help of a lens, focuses the beam tightly enough to make aiming meaningful. For detecting hits, the top of the pistol conceals a custom-made reflector that directs any IR downward into a receiver, making it omnidirectional in terms of hit sensing but only needing a single sensor.

Want to know more? Check out [Nii]’s earlier prototypes on his website. It’s clear this has been in the works for a while, so if you like seeing how a project develops, you’re in for a treat.

As for the choice of transparent OLED displays? They are certainly cool, and we remember how wild it looks to have several stacked together.

Automatic Garbage Can Keeps Cooking Cleaner

July 23, 2024 by Bryan Cockfield 30 Comments

Over the last decade or so, we’ve been inundated with appliances with wireless or “smart” technology that is often of dubious utility. No one really needs a tablet in their refrigerator or Wi-Fi on their coffee maker. A less glamorous kitchen appliance that actually might benefit from some automation and connectivity is the garbage can, or “bin” for those speaking the Queen’s English, and [Mellow_Labs] is here to show off just how to get that done with this automatic garbage can lid.

As he explains, the real impetus behind this build is to not have to touch a dirty lid while cooking to avoid having to take time to wash one’s hands again afterwards. There are a few other design criteria as well; it has to be roommate-approved so nothing permanently attached to the lid, overly complicated, or with an unnecessary amount of wires or other fixtures. A servo with an extension sits on the lid itself, and when activated forces the lid open. A distance sensor provides basic gesture recognition and a microcontroller with wireless connectivity controls both and provides home automation integration as well. With a 3D printed case that includes a quick disconnect function for easy cleaning of the lid, the build was ready to be put into service.

The first iteration used an infrared distance sensor, but placing it by an open window caused it to continuously open and close since sunlight has the same wavelengths of light the sensor is tuned for. A quick swap with an ultrasonic sensor solved the problem, and the garbage can is working flawlessly in the kitchen now. Another appliance that is generally not targeted by off-the-shelf automation solutions is the range fume hood, but another build tackled that problem a while back.

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