Author: Bryan Cockfield

1832 Articles

City Lights Telling Stories

September 12, 2014 by 27 Comments

If you’re walking around town and you see a light suddenly start to switch on and off seemingly at random, don’t discount it as a loose wire so quickly. [René] has been hard at work on a project to use city lights of all shapes and sizes for Morse messages, and a way for anyone to easily decode these messages if they happen upon one while out and about.

The lights can tell any story that is programmed into them. The code on the site is written for an Arduino-style microcontroller but it could be easily exported to any device that can switch power to turn a light on and off. Any light can work, there’s even video of a single headlight on a van blinking out some dots and dashes.

The other part of this project is a smartphone app that can decode the messages using the camera, although any Morse code interpreter can translate the messages, or if you’re a ham radio enthusiast you might recognize the messages without any tools whatsoever!

The great thing about this project is that it uses everyday objects to hide messages in plain sight, but where only some will be able to find them. This is indeed true hacker fashion! If you’re interested in making your own Morse code light, the code is available on the project site.

Homemade Omnidirectional Speakers In A Unique Enclosure

September 11, 2014 by 36 Comments

While studying acoustics in college (university for non-Americans), [Nick] had a great idea for an omnidirectional speaker. Some models available for purchase have a single speaker with a channel to route the sound in all directions, but [Nick] decided that a dodecahedron enclosure with 12 speakers would be a much more impressive route.

To accommodate the array of speakers, the enclosure needs twelve pentagons with a 58.3 degree bevel so that they fit together in a ball shape. After thinking about all of the complicated ways he could get this angle cut into the wood pentagons, he ended up using a simple circular saw!

Once the enclosure was painted [Nick] started wiring up the speakers. The equivalent impedance of the array of 8-ohm speakers works out to just around 10 ohms, which is easily driven by most amplifiers. The whole thing was hung from a custom-made galvanized pipe (all the weight adds up to about 15 kilograms, or 33 pounds for Americans, so the rig needed to be sturdy). We’ve featured other unique speaker builds, but this is the first 12-speaker omnidirectional speaker we’ve seen. [Nick] is happy to report that the speakers sound great, too!

file server

Antique Case For Custom File Server

September 11, 2014 by 46 Comments

Michigan Tech was throwing out a bunch of old electronic equipment, and [Evan] snagged quite a gem: a UHF signal generator built by Hewlett Packard circa 1955. He stripped all of the remaining electronics out of the case, but kept the slide-out trays and the front instrument panel to create this antique-looking file server.

The bottom tray was where the bulk of the electronics were housed, and since widespread adaptation of transistors for electronics wasn’t common at the time (the first silicon transistor wasn’t made until 1954), the original equipment was all vacuum tubes. This meant that there was just enough space for a motherboard, heat sink, and a couple of power supplies.

The hard drives are held in custom housings in the top portion of the case. The real magic, however, is with the front display panel. [Evan] was able to use the original meters, including a display for “megacycles” which is still technically accurate. The meters are driven by a USB-to-serial cable and a python script that runs on the server.

The antique case is a great touch for this robust file server. Make sure to put it in a prominent place, like next to your antique tube radio.

Biofeedback Flowers At Burning Man

September 10, 2014 by 14 Comments

Burning man, the premier desert-based convention, is a vacation for some. [Sam], on the other hand, points out that he is there to get his hands dirty. This year, he (with a team of six) built a set of 20 interactive lotus flowers that light up in sync with a heartbeat.

[Sam]’s biofeedback circuit is able to sense up to two heartbeats per flower. When a person’s heartbeat is detected, a set of high-power LEDs light up from the base of the stem upwards towards the petals for an incredible illuminated display of biofeedback.

The lotus flowers themselves aren’t anything to scoff at, either. They range from 8 to 18 feet high and are made out of steel and rowlux plastic. The circuit boards are all custom-made as well, with every part chosen to be as affordable as possible. The whole installation is powered by a deep-cycle marine battery and a set of 6V batteries, which can run all of the electronics in the flowers for the entire night before needing a recharge.

Burning man is a great example of art meeting technology. For other examples, check out this 2010 pyrotechnic ball, or head there yourself next August! Be sure to check out the videos and the project’s code on the project site as well.

Mood Lighting With LEDs And An Arduino

September 9, 2014 by 4 Comments

Regular candles can be awfully boring at times. They can only produce one color and the flicker is so… predictable. They can’t even be controlled by an infrared remote control, not to mention the obvious fire hazard. Now, however, [Jose] has come up with an LED candle that solves all of these problems. (Original link to the project in Spanish.)

The heart of the project is an Arduino Pro Mini, which is especially suited for this project because of its size. [Jose] put the small form-factor microcontroller in the base of a homemade wax enclosure and wired it to a Neopixel WS2812b LED strip. The strip can produce any color, and has some programmed patterns including flicker, fade, rainbow, and fire.

The artificial candle is controlled with an infrared remote control, and all of the code for the project is available on the project site if you want to build your own. [Jose] has been featured here before for his innovative Arduino-driven RGB lighting projects, and this is another great project which builds on that theme!

 

 

Infrared-controlled Light Switch

September 7, 2014 by 9 Comments

If you’re looking for your first electronics project, or a project to get someone else started in electronics, [Vadim] has you covered. Back when he was first starting out in electronics he built this infrared-controlled light switch that works with a standard TV remote control.

[Vadim]’s first few projects ended up as parts for other projects after they were built, so he wanted to build something useful that wouldn’t ultimately end up back in the parts drawer. The other requirements for the project were to use a microcontroller and to keep it simple. [Vadim] chose an ATtiny2313 to handle the RC-5 IR protocol and switch the light.

The circuit still has a switch to manually control the lights, preserving the original functionality of the light switch. The rest of the design includes a header for programming the board and another header for tying into the high voltage lines. This is a great project for anyone who knows what they’re doing with mains power but is just getting started with microcontrollers. If properly designed and implemented you’ll never stumble across a room to turn the lights out again!

Perhaps mixing high and low voltages on the same circuit board doesn’t spark your fancy or you can’t modify the light switch in your place of residence? Check out this mechanically-switched light switch.

 

Master Clock Keeps Time For All Other Clocks

September 4, 2014 by 23 Comments

[Brett] just finished construction and long-term testing of this extremely accurate timepiece. It keeps such great time by periodically syncing with the atomic clock in Mainflingen, Germany.

The core of the project is an ATMega328 which uses the new DCF77 library for decoding the signal broadcast by an atomic clock. The libraries written by Udo Klein significantly increase the noise tolerance of the device reading the signal, but they will not work with any project that use a resonator rather than a crystal.

In the event of a complete signal loss from the atomic clock, the micro driving the clock also has a backup crystal that can keep the clock running to an accuracy of within 1 second per day. The clock can drive slave clocks as well, using pulses with various timings depending on what [Brett] needs them to do. The display is no slouch either: six seven-segment displays show the time and an LCD panel reads out data about the clock. It even has chimes for the hour and quarter hour, and is full of many other features to boot!

One of the most annoying things about timekeeping is daylight savings time corrections, and this clock handles that with a manual switch. This can truly take care of all of your timekeeping needs!