Simple Solar Mason-Jar Lights

January 7, 2016 by Anool Mahidharia 12 Comments

[Michael Mogenson] built Firefly Jar – a simple circuit to light up flickering LEDs inside a standard Mason Jar, to give away to friends and family for the holidays. Given it’s simplicity and through-hole design, it’s an ideal project for a “learn to solder” class or for those wanting to get started with building some really simple electronics. There’s just a handful of parts and putting it together shouldn’t take long. Given that he’s made available all of the source design files, it should be easy for others to spin off the project.

A 55mm solar cell fits on top of the 63.5mm diameter PCB, which in turn fits perfectly in a standard Mason Jar with a collar lid. When in the light, the solar cell charges two 1.2V NiMH batteries. This also switches off the P-channel MOSFET, turning the LED’s off. The LED’s are turned on only when the solar cell voltage is low and the Ni-Mh batteries are charged. A 2.1V LDO directly drives the two LEDs with built-in flickering circuits, eliminating the need for any further parts. Check out the video of the Firefly Jar below.

Continue reading “Simple Solar Mason-Jar Lights” →

Break Your Wrist? Twitter-Enable That Plaster Cast

December 31, 2015 by Anool Mahidharia 1 Comment

Plaster casts are blank canvases for friends and family to post their get well messages. But if it’s holiday season, adding blinky LED lights to them is called for. When [Dr Lucy Rogers] hurt her hand, she put a twitter enabled LED Christmas tree on her cast.

The hardware is plain simple – some RGB LEDs, an Arduino, a blue tooth module and a battery. The LEDs and wires formed the tree, and all the parts were attached to the plaster cast using Velcro. This allowed the electronics to be removed during future X-ray scans. The fun part was in connecting the LEDs to the #CheerLights project. CheerLights is an “Internet of Things” project that allows people’s lights all across the world to synchronize to one color set by a Tweet. To program the Arduino, she used code written by [James Macfarlane] which allowed the LED color to be set to any Cheerlights color seen in blue tooth UART data.

Connectivity is coordinated using MQTT — lightweight standard popular with connected devices. By connecting the MQTT feed to the cheerlights topic from [Andy Stanford-Clark’s] MQTT feed (mqtt://iot.eclipse.org with the topic cheerlights) the lights respond to tweets (Tweet #cheerlights and a color). The LED colors can also be selected via the phone from the color picker tool in the controller, or directly via the UART. If the Bluetooth connection is lost, the LEDs change colors randomly. Obviously, delegates had great fun when she brought her Twitter enabled LED blinky lights plaster cast arm to a conference. It’s not as fun unless you share your accomplishments with others!

Must-Have Overkill Christmas Tree Lights

December 30, 2015 by Elliot Williams 9 Comments

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!

Continue reading “Must-Have Overkill Christmas Tree Lights” →

Christmas Bauble Is Neither Spherical Nor Runs Arduino

December 26, 2015 by Anool Mahidharia 11 Comments

[Jordan Wills] was tasked by his company, Silicon Labs, to build some Christmas Baubles to give away to co-workers. While the commissioned units were designed to be simple battery and LED affairs, he decided to make one of his own with bells and whistles. His Mario themed Christmas Ornament uses a Silicon Labs FM972 micro controller, capacitive sensing, PWM controlled 8 bit audio, and blinky lights.

The interesting part is some of the construction techniques that he used. The finger-joint style cube is built from circuit boards. Electrical connections between panels were routed using solder wicking copper braid. That’s a interesting trick which we’ll keep in mind along with some of our favorite creative structural uses of PCB.

The top of the cube has four LED’s which light up the Mario “Question Mark” symbols on the four sides of the cube while the base contains all of the electronics. The outside of the base piece was a large copper plane to act as the capacitive sensing element. This meant all electronics needed to be surface mounted with tracks laid out on one side – which posed some layout challenges. Adding the Capacitive sense function was a cinch thanks to support from the in-house design team. PWM output from the micro controller takes care of audio, and the output is routed through a buffer to boost the signal. A bandpass filter then cleans up the PWM output before feeding it to the speaker.

Continue reading “Christmas Bauble Is Neither Spherical Nor Runs Arduino” →

Comparing Movies Between Rottentomatoes And IMDB

December 26, 2015 by James Hobson 7 Comments

Well, it’s the holiday season! Which means two things. Long, sometimes uncomfortable gatherings with family, and our favorite — free time. So if you’re looking to catch up on some movies, [Rajesh Verma] has you covered. He’s compiled a database that aggregated data from both Rotten Tomatoes and IMDB!

That means you can very easily sort through based on critic’s favorite, audience favorite, IMDB favorite, underrated, overrated, year, etc. He started by dabbling with aggregation scripts with just Rotten Tomatoes, and after he released one showing both Audience and Critic scores, Rotten Tomatoes updated their site to include that sorting method! Coincidence? Maybe.

Either way, it broke his original script when the site was updated — so he’s come back with something even better — a list for both IMDB and Rotten Tomatoes.

He started the project thanks to [Michael] at Meta Film List, who had the idea of making movie databases more accessible. Without further ado, you can check out the list on Google Docs.

Cyberpunking Home Alone

December 25, 2015 by Mike Szczys 7 Comments

~~[Macaulay Culkin]~~ err… [Kevin McCallister] pulled off some epic 1990 hacks to scare off a couple of bumbling burglars in the classic film Home Alone. Now celebrating its 25th Anniversary, it’s fun to see the tricks [Kevin] used to spoof a house party brought into this age of high-technology.

The trick in the original movie was all about silhouettes in the windows that made the house look full of people. [Michael Jordan’s] cardboard cutout taped to a model train is fairly believable. But really, who has a half-dozen mannequins just sitting in their attic? Creepy.

The marketing company RedPepper are behind the facelift of this pop culture icon. They outfitted their offices with some window dressings that are perfect for the silhouettes. In a delightful cyberpunk twist they went with projects and digital silhouettes. Embracing our current tech-heavy lives is the mobile aspect of it all. Of course there’s an app for that. It means [Kevin] doesn’t have to pull the strings. He can hide outside the building and decide which animations are played by the projectors within. Check it out after the break.

Continue reading “Cyberpunking Home Alone” →

Here Comes Santa Claws

December 24, 2015 by Richard Baguley 4 Comments

Liberty Games in the UK was looking for a fun way to support charity for the holidays, and we think they succeeded. They decided to set up an arcade crane machine to run over the internet, with each type of toy snagged earning a donation. Snag a bear, and they will donate £5 to St Mungos, a UK charity that works with homeless or at risk people. Snag one of the rarer Santa toys, and they will donate £20. It’s a great cause, and a nice hack. Behind the scenes, the Internet side of things runs on a Raspberry Pi connected to a PiRack and a couple of PiFace digital interface cards that are wired into the electronics of the crane machine so they could control the buttons on the machine from a Web interface. Unfortunately, it didn’t seem to be running when we tried it, but hopefully someone will give the machine a swift kick shortly to get it going until the Hackaday traffic invariably brings it down again.

One of the interesting thing that they discovered while working on these hacks: they have a pay-out ratio that is determined by the strength of the grabbing arm. The owner can tweak this so that the arm does not grab very firmly, which means a dropped bear. Want to torture your friends with hopes of snagging the best stuffed animals?. Follow the example of this claw machine build all from parts on hand.