“Trataka” by Alessio Chierico is an interactive installation controlled by Arduino and based on a brain-computer interface. It was exhibited at Ars Electronica last week. When a visitor totally relaxes and focuses, the candle magically extinguishes:

Trataka is a Sanskrit term which means “to look” or “to gaze” and it refers to a meditation technique. This practice consists in concentrate the attention in a small object, or more commonly in a flame. In meditation, this technique is used to stimulate the ajna chakra: a point located in correspondence of the brain. According to the Hindu tradition, this chakra is one of the six main centers of vital energy, and it is considered as the eye of the intuition and the intellect.

This installation is composed by a brain-computer interface that detect the brain waves and defines parameters like the level of attention. Wearing this device, the user is invited to concentrate his attention on a flame placed in front of him. The level of attention detected by this system, controls an air flow located under the flame: higher level corresponds with a more intense air flow. The interaction process aims to the user engagement for increase his attention in order to put the flame out. This will happen when the highest level of attention is reached: the air flow become strong enough to extinguish the flame.

 

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!

We’d like to share the performance, by Opificio Sonico,  recorded live in July 2014 of  Toa Mata Band, best known as the “World’s first LEGO robotic band” and controlled by Arduino Uno which is hooked up to a MIDI sequencer:

In this video, the third episode, the robots are playing some unconventional drum-percussions made by some food packaging are captured by a contact microphone (piezo) and processed in real time in the D.A.W. Ableton Live. A brand new device appears for the first time, it’s a moving platform on x-axis, made of Lego bricks, gears and servo motors that permits to move with semitones-steps the tiny synth. The song is a cover of the famous synth-pop band Depeche Mode, it’s a personal tribute to the band who made my days in the 80′s.

The Raspberry Pi has been the basis for many cool projects. Even so, Models A and B have been criticized for having only a handful of GPIO pins available. Sure, the new Model B+ has a 40-pin GPIO header but what if you want to use your old RaspPi with a bunch of in and outputs? [Steve] is one of those guys and has done something about it by creating a pretty neat solution he calls the PiMagic. It’s a Pi Plate that has an on board ATMEGA328 running an Arduino bootloader. The RaspPi and the Arduino communicate via UART as [Steve] felt it was a bit simpler than going the SPI or I2C route.

The RaspPi GPIO’s run on 3.3v and the ATMEGA328’s like 5v. To solve this, the PiMagic has a Level Shifter that keeps the I/O of the two boards happy. Older Pi’s had a problem burning out PCB traces when supplying too much current on the 5v supply line. [Steve] threw in a fuse that will burn out before the Pi does to ensure that no Pi’s were harmed in the making of this project.

Now that a bunch of I/O are available, how do you physically access them? Well, the PiMagic has female headers in the typical Arduino layout. This way any Arduino Shield will plug right in. [Steve] made all his source files available for those who want to make one themselves. Find an assembly video after the break.

Nikodem is a young maker  based in Poland and shared with us his latest project based on Arduino Leonardo. It’s a DIY bike tachometer providing you with a set of additional information:

It shows your speed, the average speed, the temperature, the trip time and the total distance. You can change it using the button. Additionally, the speed is shown on a tachometer. I built it because I like building new things, I have not found anything like this on the internet so I want to show you how to build a good speedometer as the one on my bike is not as cool as I want .

You can find all the steps to make one yourself on  his Instructable account, and in the meanwhile take a look at the two videos below.

What’s better than an ordinary end table? How about an end table that can serve you beer? [Sam] had this exact idea and used his skills to make it a reality. The first step of the build was to acquire an end table that was big enough to hold all of the components for a functional kegerator. This proved to be a bit tricky, but [Sam] got lucky and scored a proper end table from a garage sale for only $5.00.

Next, [Sam] used bathroom sealant to seal up all of the cracks in the end table. This step is important to keep the inside cold. Good insulation will keep the beer colder, while using less electricity. Next, a hole was cut into the top of the table for the draft tower.

The draft tower is mounted to a couple of drawer slides. This allows the tower to raise up and down, keeping it out of sight when you don’t want it. The tower raises and lowers using a simple pulley system. A thin, high strength rope is attached to the tower. The other end is attached to a spool and a small motor. The motor can wind or unwind the spool in order to raise and lower the tower.

The table houses an Arduino, which controls the motor via a homemade H bridge. The Arduino is hooked up to a temperature sensor and a small LCD screen. This way, the users can see how cold their beer will be before they drink it.

To actually keep the beer cold, [Sam] ripped apart a mini fridge. He moved the compressor and condenser coils to the new table. He had to bend the coils to fit, taking care not to kink them. Finally he threw in the small keg, co2 tank and regulator. The final product is a livingroom gem that provides beer on demand.

Demo video (which is going the wrong way) can be found after the break.

[Jose's] latest project brings an old visual effect toy up to date with digital electronics. Most of us are familiar with inexpensive kaleidoscope toys. Some of us have even built cheap versions of them with paper tubes, mirrors, and beads. [Jose] wanted to try to recreate the colorful pattern effects created by a kaleidoscope using an Arduino and an addressable LED strip.

The build is actually pretty simple. The base is a disc of PVC cut to just a few inches in diameter. [Jose] started with an addressable LED strip containing 60 LEDs. He then cut it into 12 sections, each containing five LEDs. The smaller strips were then mounted to the disc, similar to spokes on a bicycle wheel. The LED strip already has an adhesive backing, so that part was trivial.

The final step was to add some kind of diffuser screen. The LED strips on their own are not all that interesting. The diffuser allows the light to blend together, forming interesting patterns that are more reminiscent of the patterns you might see in a real kaleidoscope. Without the diffuser you would just see individual points of light, rather than blended color patterns.

The whole thing is controlled by a small Arduino. [Jose] has made the code available at the bottom of his blog post. Be sure to watch the video of the system in action below.

[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!

A new release of OpenWrt-Yún was announced today on Arduino Forum by Federico Fissore and you can download it from this page.

1.4.2 includes both bug fixes and new stuff.
We fixed some glitches in the webpanel (a bug was found by wildpalms: thank you!).
The OpenWRT Image Builder and the software produced by the http://allseenalliance.org/ is now available for download.

Compared to 1.4.1 this release contains:

• OpenWrt-Yún (Linux side)
  Added “image builder” to the build process. See details on Github
  Added alljoyn feeds and packages. See details on Github

• Web panel
  Fixed wrong JSONP serialization. See details on Github
  Fixed a javascript error in webpanel login page

The complete list of changes is available here.