This Cup Holder Crystal Ball Tells Your MPG Future

November 1, 2018 by Tom Nardi 22 Comments

Hybrid vehicles, which combine an eco-friendly electric motor with a gasoline engine for extended range, are becoming more and more common. They’re a transitional technology that delivers most of the advantages of pure electric vehicles, but without the “scary” elements of electric vehicle ownership which are still foreign to consumers such as installing a charger in their home. But one element which hybrids are still lacking is a good method for informing the driver whether they’re running on petroleum or lithium; a way to check at a glance how “green” their driving really is.

[Ben Kolin] and his daughter [Alyssa] have come up with a clever hack that allows retrofitting existing hybrid vehicles with an extremely easy to understand indicator of real-time vehicle efficiency. No confusing graphics or arcade-style bleeps and bloops, just a color-changing orb which lives in the cup holder. An evolved version which takes the form of a smaller “dome light” that sits on the top of the dashboard could be a compelling aftermarket accessory for the hybrid market.

The device, which they are calling the ecOrb, relies on an interesting quirk of hybrid vehicles. The OBD II interface, which is used for diagnostics on modern vehicles, apparently only shows the RPM for the gasoline engine in a hybrid. So if the car is in motion but the OBD port is reporting 0 RPM, the vehicle must be running under electric power.

With a Bluetooth OBD adapter plugged into the car, all [Ben] and [Alyssa] needed was an Arduino Nano clone with a HC-05 module to read the current propulsion mode in real-time. With some fairly simple conditional logic they’re able to control the color of an RGB LED based on what the vehicle is doing: green for driving on electric power, purple for gas power, and red for when the gas engine is at idle (the worst case scenario for a hybrid).

Check out our previous coverage of OBD hacking on the Cadillac ELR hybrid if you’re looking to learn more about what’s possible with this rapidly developing class of vehicle

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LED Stick Person Costume Lights Up The Night

October 31, 2018 by Drew Littrell 16 Comments

Sometimes a simple idea can yield fantastic results. A few runs of LED strips fastened to a black hoody and sweatpants and just like that…a LED stick person costume for Halloween. The creator of the “Glowy Zoey” [Royce] originally put together some glow in the dark stick person suits to stand out when hitting the slopes at night. Now he’s taken that simple idea for a costume and made a small business out of it.

“I had a lot of extra parts laying around. I gathered everything up and got to work soldering.” – Royce Hutain

The suits themselves consist of button snaps and ribbon loops sewn into a pattern that routes the LED strips around the jacket’s hood and down each arm. To make the lighting effect pop, an all black plastic mask is used to cover the wearer’s face. It wouldn’t be that much a stretch to substitute EL wire in place of the LED strips if one were so inclined. We’d wager a number of you could pull this off straight out of the junkbox.

The Glowy Zoey stick figure suits even received some mainstream television press a few years ago when they were featured on Jimmy Fallon’s Late Night show. Note that visiting the Glowy Zoey website may take you back a bit since it features one of those autoplay jingles that were so prevalent in the Web 1.0 days. In fact the same jingle is used in the video below from their YouTube channel:

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History Of White LEDs

October 29, 2018 by Brian Benchoff 122 Comments

Compared to incandescent lightbulbs, LEDs produce a lot more lumens per watt of input power — they’re more efficient at producing light. Of course, that means that incandescent light bulbs are more efficient at producing heat, and as the days get shorter, and the nights get colder, somewhere, someone who took the leap to LED lighting has a furnace that’s working overtime. And that someone might also wonder how we got here: a world lit by esoteric inorganic semiconductors illuminating phosphors.

The fact that diodes emit light under certain conditions has been known for over 100 years; the first light-emitting diode was discovered at Marconi Labs in 1907 in a cat’s whisker detector, the first kind of diode. This discovery was simply a scientific curiosity until another discovery at Texas Instruments revealed infrared light emissions from a tunnel diode constructed from a gallium arsenide substrate. This infrared LED was then patented by TI, and a project began to manufacture these infrared light emitting diodes.

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Easy Blinking LED Eyes For Halloween

October 28, 2018 by Tom Nardi 16 Comments

There’s not much time left now. If you’re going to put something together to give the youngsters some night terrors in exchange for all that sweet candy, you better do it quick. This late to the game you might not have time to do anything too elaborate, but luckily we’ve come across a few quick Halloween hacks that can get you some pretty cool effects even if it’s only a few hours before the big night.

As a perfect example, these LED “blinking eyes” were created by [Will Moser]. Using nothing more exotic than some bare LEDs, an Arduino, and a cardboard box, these little gadgets can quickly and easily be deployed in your windows or bushes to produce an unsettling effect after the sun goes down. Thanks to the pseudorandom number generator in the Arduino code, the “eyes” even have a bit of variability to them, which helps sell the idea that your Halloween visitors are being watched by proper creatures of the night.

The hardware side of this project is very simple. [Will] takes a container such as a small cardboard box and cuts two holes in it to serve as the eyes. He notes that containers which are white or reflective on the inside work best. You’ll want to get a little artistic here and come up with a few different shaped sets of eyes, which is demonstrated in the video after the break. Inside each box goes a colored LED, wired back to the Arduino.

For the software, [Will] is using a floating analog pin as a source of random noise, and from there comes up with how often each LED will blink on and off, and for how long. Both the hardware and software sides of this project are perfect for beginners, so it might be a good way to get the Little Hackers involved in the festivities this year; if you’re the type of person who enjoys replicating small humans in addition to creeping them out.

LEDs seem to be the hacker’s decoration of choice come Halloween, from wearable LED eyes to remote controlled illuminated pumpkins.

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Custom LED Signage From Household Items

October 27, 2018 by Tom Nardi 6 Comments

We’ll admit it: sometimes we overthink things. We imagine some of you are the same way; there seems to be something in the hacker mentality that drives us to occasionally over-engineer ideas to the point of unrecognizability. There’s nothing inherently wrong with this, but sometimes it does keep us from seeing easier solutions.

For example, the very slick looking personalized LED sign (Google Translate) that [Clovis Fritzen] recently wrote in to share with us. If we were tasked with creating something like this there would certainly have been a 3D printer and likely a CNC involved before all was said and done, and a few days later we’d still be working out the bugs in our OpenSCAD code. But his approach is very different. Fantastically simple and constructed largely from household items, this is a good project to keep the Junior Hackers entertained on a rainy weekend.

The first step of the process is to draw out the characters you want onto a piece of cardboard, and then carefully cut it out. If you’re worried that you’re not particularly artistic, this step will go a bit better if you print out the design and tape the paper over the cardboard to serve as a template. Once you’ve got your design cut out, you glue or tape a piece of standard printer paper over it. This is the face of the display; it just needs to be lit from behind.

If you wanted to make a sign that was just a single color and didn’t have individually addressable elements, then it would be enough to illuminate the whole cutout with a single light source. But where’s the appeal in that? As [Clovis] shows, you can get much better results by constructing a segmented box, with one LED in each cell. By wiring each LED to a pin on an Arduino or other microcontroller, you’ll have control over the color and brightness of each section of the sign.

Of course, if you’re not big on the whole cardboard aesthetic, you could even recreate this design with the aforementioned CNC and 3D printer. [Clovis] shows how the basic concept works, and that it can be scaled pretty easily depending on the kind of materials you have access to.

IoT Traffic Light Is Cardboard Made Fun

October 20, 2018 by Lewin Day 10 Comments

Traffic lights! Kids love them, hackers love them, and they’re useful in industrial contexts to see if the giant machine is currently working or having a bad day. While the real deal are unwieldy and hard to come by, there’s nothing stopping you tackling a fun cardboard build at home.

It’s a great way to teach kids about traffic rules, too.

In this case, the light is courtesy of WS2812b LED strips. They’re a great choice, as they interface easily with most microcontrollers thanks to readily available libraries. An ESP8266 runs the show here, serving up a basic web interface over WiFi. This allows the color of the various LEDs to be controlled remotely. It also allows the lights to be switched on and off to direct whatever traffic you may be controlling. The whole project is all wrapped up in a simple cardboard enclosure, mimicking the municipal street furniture which so resolutely commands our movements.

The cardboard traffic light is a project that shows just what can be done with some off-the-shelf parts and some good old-fashioned kindergarten-style arts and crafts. If you find yourself similarly admiring these devices, check out our primer on the North American traffic signal. Video after the break.

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Shedding A Bit Of Light On Some Logic

October 15, 2018 by Jenny List 30 Comments

When it comes to logic technologies, we like to think we’ve seen them all here at Hackaday. But our community never ceases to surprise us with its variety and ingenuity, so it should be a surprise that [Dr Cockroach] has delivered one we’ve not seen before. Light logic doesn’t use the conventional active devices you’d expect such as transistors, tubes, or even relays. Instead, it uses LEDs and CdS cells to make rudimentary switches. So far there is a NAND, a NOR, and a set-reset latch that appears in the video below the break, and it is not inconceivable that much more complex devices could be crafted.

The CdS cell switch is not too far different in operation to a transistor, with the CdS cell forming half of a potential divider as a rough equivalent of a collector-emitter circuit, and the LED feeding its light to the cell and forming a rough equivalent of a base circuit. It would probably not form a very good analog of a transistor and it seems likely that is will not be the fastest of devices, but we applaud the ingenuity in coming up with it.

CdS cells are a component that seems almost to come from another era, redolent of childhood electronic kits from days of yore. It’s no surprise we don’t see them too often, though, they pop up in the occasional automatic sunglasses.

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