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:
A proper soldering iron is one of the fundamental tools that a good hacker needs. Preferably one that has a temperature control so it can handle different types of solder and connectors.
Decent soldering stations aren’t cheap, but [Code and Solder] show you how to make one for about $15 in parts. This uses a cheap non-temperature-controlled USB soldering iron, an Arduino and a few other bits that they got from AliExpress. The plan is to add a thermocouple to the soldering iron, and let the Arduino control the temperature. A rotary dial and LCD screen control the set-point, and the Arduino switches the feed to the heating element on and off through the FET.
It’s not the cleanest build in the world, and these USB soldering irons aren’t suitable for large joints or long soldering jobs, but it’s a neat little hack for the builder on a budget. We’ve seen teardowns of these rather neat little USB soldering irons before, but this is an interesting way to expand its capabilities.
One of the standout talks at the 33rd Chaos Communications Congress concerned pseudo-random-number generators (PRNGs). [Vladimir Klebanov] (right) and [Felix Dörre] (left) provided a framework for making sure that PRNGs are doing what they should. Along the way, they discovered a flaw in Libgcrypt/GNUPG, which they got fixed. Woot.
Cryptographically secure random numbers actually matter, a lot. If you’re old enough to remember the Debian OpenSSL debacle of 2008, essentially every Internet service was backdoorable due to bad random numbers. So they matter. [Vladimir] makes the case that writing good random number generators is very, very hard. Consequently, it’s very important that their output be tested very, very well.
So how can we test them? [Vladimir] warns against our first instinct, running a statistical test suite like DIEHARD. He points out (correctly) that running any algorithm through a good enough hash function will pass statistical tests, but that doesn’t mean it’s good for cryptography. Continue reading “33C3: How Can You Trust Your Random Numbers?”→
Here’s a blast from the past, or future, reminiscent of the self-lacing shoes from Back to the Future Part II. [Vimal Patel] made his own self-lacing shoe using LEGO “bolted” to the shoe’s sole. We think these are cooler than the movie version since we get to see the mechanism in action, urging it on as the motor gets loaded down pulling the laces for that last little bit of tightness.
The electronics are all LEGO’s Power Functions parts. A Dremel was used to make holes in the soles to hot glue LEGO pieces for four attachment points. The attachment points are permanent but the rest can be easily removed. In case you want to look them up or make your own, he’s using the using the 8878 rechargeable LiPo battery box, the 88003 L-motor, the 8884 IR receiver, and the 8885 IR remote control. That’s right, these shoes are laced up under command of an IR remote control, well, provided the battery box is powered on. There’s a 1:24 worm gear reduction to get the needed torque.
This was a quick build for [Patel], done over two afternoons. He initially tried with the winding axle behind the heel but that didn’t work well so he moved the axle adjacent to the laces instead, which works great as you can see in the video after the break.
In the days before semiconductor diodes, transistors, or even vacuum tubes, mechanical means were used for doing many of the same things. But there’s still plenty of fun to be had in using those mechanical means today, as [Manuel] did recently with his relay computer. This post is a walk through some circuits that used those mechanical solutions before the invention of the more electronic and less mechanical means came along.
This Friday at 5pm PST, [Sprite_tm] will be leading a Hack Chat talking about the ESP32.
[Sprite_tm] should require no introduction, but we’re going to do it anyway. He’s can install Linux on a hard drive. He can play video games on his keyboard. He built the world’s tiniest Game Boy, and gave the greatest talk I’ve ever seen. Right now, [Sprite] is in China working on the guts of the ESP32, the next great WiFi and Bluetooth uberchip.
[Sprite] recently packed his bags and headed over to Espressif, creators of the ESP32. He’s one of the main devs over there, and he’s up to his neck in the varied and weird peripherals contained in this chip. His job includes porting NES emulators to a WiFi-enabled microcontroller. If you want to learn about the latest and greatest microcontroller, this is the guy you want to talk to, and he’s taking all questions.
Note that we usually do these things earlier in the day but this week we start rolling at 5 PM Pacific Friday to help match up with [Sprite’s] timezone. You can figure out when this event will happen with this handy time and date converter.
Here’s How To Take Part:
Buttons to join the project and enter the Hack Chat
Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. Log into hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.
You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.
And Tindie Too
In addition to [Sprite]’s Hack Chat on Friday, we’re going to have a Tindie Chat in the Tindie Dog Park on Friday at noon, Pacific time. You can figure out when that’ll be in your local time by following this link.
In the Tindie Chat, we’re going to be talking about all the aspects of selling hardware on Tindie. This is a phenomenal community that keeps on growing, and right now there’s some really, really cool hardware being offered up from makers and creators around the world.
Upcoming Hack Chats
We have a few more Hack Chats on the books. On February 10th, we’ll be talking RF with [Jenny List]. Sparkfun will be around for a Hack Chat on February 17th. If stats are your thing, we’ll have a chat on the ins and outs of R in a few weeks.
Most of our readers are already going to be familiar with how electromagnets work — a current is induced (usually with a coil) in a ferrous core, and that current aligns the magnetic domains present in the core. Normally those domains are aligned randomly in such a way that no cumulative force is generated. But, when the electric field created by the coil aligns them a net force is created, and the core becomes a magnet.
As you’d expect, this is an extremely useful concept, and electromagnets are used in everything from electric motors, to particle accelerators, to Beats by Dre headphones. Another use that you’re probably familiar with from your high school physics class is levitation. When two magnets are oriented with the same pole towards each other, they repel instead of attract. The same principle applies to electromagnets, so that an object can be levitated using good ol’ electricity.
That, however, isn’t the only way to levitate something using magnets. As shown in the video below, permanent magnets can be used to induce a current in conductive material, which in turn exerts a magnetic field. The permanent magnets induce that current simply by moving — in this case on rotors spun by electric motors. If the conductive material is placed below the magnets (like in the video), it will push back and you’ve got levitation.
