Antenna Hidden In Holiday Lights Skirts HOA Rules

February 27, 2023 by Bryan Cockfield 87 Comments

For all their supposed benefits, homeowner’s associations (HOAs) have a reputation of quickly turning otherwise quaint neighborhoods into a sort of Stanford prison experiment, as those who get even the slightest amount of power often abuse it. Arbitrary rules and enforcement abound about house color, landscaping, parking, and if you’ve ever operated a radio, antennas. While the FCC (at least as far as the US is concerned) does say that HOAs aren’t permitted to restrict the use of antennas, if you don’t want to get on anyone’s bad side you’ll want to put up an antenna like this one which is disguised as a set of HOA-friendly holiday lights.

For this build, a long wire is hidden along with a strand of otherwise plain-looking lights. While this might seem straightforward at first, there are a few things that need to be changed on the lighting string in order to make both the antenna and the disguise work. First, the leads on each bulb were removed to to prevent any coupling from the antenna into the lighting string. Clipping the leads turns what is essentially a long wire that might resonate with the antenna’s frequency into many short sections of wire which won’t have this problem. This also solves the problem of accidentally illuminating any bulbs when transmitting, as the RF energy from the antenna could otherwise transfer into the lighting string and draw attention from the aforementioned HOA.

Tests of this antenna seemed to show surprising promise while it was on the ground, but when the string and antenna was attached to the roof fascia the performance dropped slightly, presumably because of either the metal drip edge or the gutters. Still, the antenna’s creator [Bob] aka [HOA Ham] had excellent success with this, making clear contacts with other ham radio operators hundreds of miles away. We’ve shared another of [Bob]’s HOA-friendly builds below as well which hides the HF antenna in the roof’s ridge vent, and if you’re looking for other interesting antenna builds take a look at this one which uses a unique transformer to get wide-band performance out of an otherwise short HF antenna.

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Computer Vision Maps Christmas Lights

November 3, 2020 by Bryan Cockfield 26 Comments

There’s a small but dedicated group of folks out there who spend all year planning their Christmas decorations. These aren’t simple lawn ornaments or displays, either, but have evolved into complex lightning performances that require quite a bit of computer control. For some things, hooking up a relay to a microcontroller can get the job done, but [Andy] has turned to computer vision to solve some of the more time-consuming aspects of these displays.

Specifically, [Andy] has a long string of programmable RGB LED lights to wrap around a Christmas tree, but didn’t want to spend time manually mapping out each light’s location. So he used OpenCV to register the locations of the LEDs from three different camera angles, and then used a Python script to calculate their position in the 3D space. This means that he will easily be able to take the LEDs down at the end of the holidays and string them back up next year without having to do the tedious manual mapping ever again.

While [Andy] notes that he may have spent more time writing the software to map out the LEDs than manually doing it himself, but year-after-year it may save him a lot of time and effort, not to mention the benefits of a challenge like writing this software in the first place. If you want to get started on your own display this year, all you really need is some lights and a MIDI controller.

Take Security Up A Notch By Adding LEDs

January 12, 2020 by Bryan Cockfield 14 Comments

All computers are vulnerable to attacks by viruses or black hats, but there are lots of steps that can be taken to reduce risk. At the extreme end of the spectrum is having an “air-gapped” computer that doesn’t connect to a network at all, but this isn’t a guarantee that it won’t get attacked. Even transferring files to the computer with a USB drive can be risky under certain circumstances, but thanks to some LED lights that [Robert Fisk] has on his drive, this attack vector can at least be monitored.

Using a USB drive with a single LED that illuminates during a read OR write operation is fairly common, but since it’s possible to transfer malware unknowingly via USB drives, one that has a separate LED specifically for writing operations will help alert a user to any write operations that might be trying to fly under the radar. A recent article by [Bruce Schneier] pointed out this flaw in USB drives, and [Robert] was up to the challenge. His build returns more control to the user by showing them when their drive is accessed and in what way, which can also be used to discover unique quirks of one’s chosen operating system.

[Robert] is pretty familiar with USB drives and their ups and downs as well. A few years ago he built a USB firewall that was able to decrease the likelihood of BadUSB-type attacks. Be careful going down the rabbit hole of device security, though, or you will start seeing potential attacks hidden almost everywhere.

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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Bringing A Christmas Lights Show Inside

December 21, 2017 by James Hobson 15 Comments

Instructables user [Osprey22] has been building towards this Christmas for years. Why? This year, he has brought an impressive musical Christmas light display inside, and at a fraction of the cost too!

An box at the tree’s base hides the power supply and the controller boards — a Raspberry Pi and a SanDevices e682 Pixel controller for the 400 WS2811 RGB LEDs — with an added router to connect them to the main network. The Pi is running Falcon Pi Player and a projector somewhere in the region of $100 complements the light show.

As far as mapping out the LEDs, Xlights is the program of choice, locating the LEDs in space with the help of a cell phone video recording. [Osprey22] had to write a quick program in C to fix the LED overlaps in the grid. (A spreadsheet would work just as well, here). Oh, and the gifts at the bottom of the tree double as a projector screen!

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A Mobile Bar In A Trailer!

June 4, 2017 by James Hobson 4 Comments

Ok, there are some worthy laws in place regulating the sale and distribution of alcohol — and for good reason. For many a bootlegger, however, the dream of renovating an old trailer from 1946 into a mobile bar is a dream that must– wait, what? That already exists?

It’s no mobile workshop, but the bar was initially built to accommodate guests at their wedding. [HelloPennyBar] has shared the reconstruction process with the world. Inside, there’s everything you’d need to serve beverages, including a (double) kitchen sink. In addition to a water tank, a pair of car batteries serve as the central power with electrical work installed for interior lights, a small fan to keep the bartenders cool, exterior lights, a water pump, the trailer lights, and more exterior lights so the patrons can party the night away.

Before you say anything, [HelloPennyBar] says they would need a license to sell alcohol, but alleges that for serving alcohol at private events in their state it suffices to have an off-site responsible serving license. Furthermore, a few helpful redditors have chimed in regarding battery safety and cable-mounts, to which [HelloPennyBar] was amenable. Safety and legality noted, the mobile bar must make for a novel evening of fun.

[via /r/DIY]

A Very MIDI Christmas Lightshow

February 1, 2017 by James Hobson 22 Comments

Christmas light displays winking and flashing in sync to music are a surefire way to rack up views on YouTube and annoy your neighbours. Inspired by one such video, [Akshay James] set up his own display and catalogued the process in this handy tutorial to get you started on your own for the next holiday season.

[James], using the digital audio workstation Studio One, took the MIDI data for the song ‘Carol of the Bells’ and used that as the light controller data for the project’s Arduino brain. Studio One sends out the song’s MIDI data, handled via the Hairless MIDI to serial bridge, to the Arduino which in turn sets the corresponding bit to on or off. That gets passed along to three 74HC595 shift registers — and their three respective relay boards — which finally trigger the relay for the string of lights.

From there, it’s a matter of wiring up the Arduino shift register boards, relays, and connecting the lights. Oh, and be sure to mount a speaker outdoors so passers-by can enjoy the music:

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