When Appliance Hackers Hit The Music Scene

The art-music-technology collective “Electronicos Fantasticos!” (commonly known as Nicos) is the brain child of artist/musician [Ei Wada] in Japan. They revive old, retired and out-dated electrical appliances as new “electro-magnetic musical instruments” creating not just new ways to play music, but one that also involves the listener as a musician, gradually forming an interactive orchestra. They do this by creatively using the original functions of appliances like televisions and fans, hacking them in interesting ways to produce sound. The project started in the beginning of 2015, leading to the creation of a collaborative team — Nicos Orchest-Lab — around the end of that year. They have since appeared in concerts, including a performance at “Ars Electronica”, the world’s largest media arts festival in 2019.

For us hackers, the interesting bits can be found in the repository of their Work, describing sketchy but tantalising details of the musical instruments. Here are a few of the more interesting ones, but do check out their website for more amazing instruments and a lot of entertaining videos.

CRT-TV Gamelan – A percussion instrument made from old CRT monitors. Coloured stripes projected on the screen cause changes in static-electricity picked up by the players hands, which then propagates to an electrical coil attached to their foot. This signal is then patched to a guitar amplifier.

Electric Fan Harp – They take out the fan blade, and replace it with a “coded disk” containing punched holes. Then they shine a bulb from under the rotating disk, and the interrupted light is picked up by an optical receiver held by the player. Controlling the fan speed and the location of the receiver pickup, they can coax the fan to produce music – based on the idea “What if Jimi Hendrix, the god of electric guitars, played electric fans as instruments?”

Barcoder – This one is quite simple but produces amazing results, especially when you pair up with another Barcoder musician. The output of the barcode reader is pretty much directly converted to sound – just wave the wand over printed barcode sheets. And it works amazingly well when pointed at striped shirts too. Check out the very entertaining videos of this gizmo. This led to the creation of the Barcodress – a coded dress which creates an interactive music and dance performance.


The Striped Shirtsizer

Striped Shirtsizer – This one is a great hack and a synth with a twist. A camera picks up video signals, which is then fed to the “Audio” input of an amplifier directly. In the video on the project page, [Ei Wada] explains how he accidentally discovered this effect when he wrongly plugged the “yellow” video out connector to the audio input of his guitar amplifier. At an outdoor location, a bunch of people wearing striped shirts then become an interactive musician-audience performance.

The Kankisenthizer

Kankisenthizer a.k.a Exhaust Fancillator  – This one consists of an array of industrial exhaust fans – although one could just as well use smaller instrument cooling fans. On one side is a bright light, and on the other a small solar cell. Light fluctuations picked up by the solar cell are then fed to the guitar amplifier. The array consists of fans with different numbers of blades. This, coupled with changing the fan speed, results in some amazing sound effects.

There’s a whole bunch more, and even though the “instructions” to replicate the instruments aren’t well documented, there’s enough for anyone who’s interested to start experimenting.

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Extremely Simple Tesla Coil With Only 3 Components

Tesla Coils are a favourite here at Hackaday – just try searching through the archives, and see the number of results you get for all types of cool projects. [mircemk] adds to this list with his Extremely simple Tesla Coil with only 3 Components. But Be Warned — most Tesla coil designs can be dangerous and ought to be handled with care — and this one particularly so. It connects directly to the 220 V utility supply. If you touch any exposed, conductive part on the primary side, “Not only will it kill You, it will hurt the whole time you’re dying”. Making sure there is an ELCB in the supply line will ensure such an eventuality does not happen.

No prizes for guessing that the circuit is straight forward. It can be built with parts lying around the typical hacker den. Since the coil runs directly off 220 V, [mircemk] uses a pair of fluorescent lamp ballasts (chokes) to limit current flow. And if ballasts are hard to come by, you can use incandescent filament lamps instead. The function of the “spark gap” is done by either a modified door bell or a 220 V relay. This repeatedly charges the capacitor and connects it across the primary coil, setting up the resonant current flow between them. The rest of the parts are what you would expect to see in any Tesla coil. A high voltage rating capacitor and a few turns of heavy gauge copper wire form the primary LC oscillator tank circuit, while the secondary is about 1000 turns of thinner copper wire. Depending on the exact gauge of wires used, number of turns and the diameter of the coils, you may need to experiment with the value of the capacitor to obtain the most electrifying output.

If you have to look for one advantage of such a circuit, it’s that there is not much that can fail in terms of components, other than the doorbell / relay, making it a very robust, long lasting solution. If you’d rather build something less dangerous, do check out the huge collection of Tesla Coil projects that we have featured over the years.

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AVR Microcontroller Doubles Up As A Switching Regulator

[SM6VFZ] designed, built and tested a switched-mode DC-DC boost regulator using the core independent peripherals (CIP) of an ATtiny214 micro-controller as a proof of concept, and it looks pretty promising!

A Buck, Boost, or Buck-Boost switching regulator topology usually consists of a diode, a switching element (MOSFET) and an energy storage device (inductor/capacitor) in the power path, and a controller that can measure the output voltage, control the switching element and add safety features such as current limiting and temperature shutdown. A search for switching regulators or controllers throws up thousands of parts, and it’s possible to select one specifically well suited for any desired application. Even so, the ability to use the micro-controller itself as the regulator can have several use cases. Such an implementation allows for a software configurable switch-mode regulator and easy topology changes (boost, buck, fly back etc.).

The “Getting Started with Core Independent Peripherals on AVR®” application note is a good place to get an overview of how the CIP functionality works. Configurable Custom Logic (CCL) is among one of the powerful CIP peripherals. Think of CCL as a rudimentary CPLD — a programmable logic peripheral, which can be connected to a wide range of internal and external inputs such as device pins, events, or other internal peripherals. The CCL can serve as “glue logic” between the device peripherals and external devices. The CCL peripheral offers two LookUp Tables (LUT). Each LUT consists of three inputs, a truth table, a synchronizer, a filter, and an edge detector. Each LUT can generate an output as a user programmable logic expression with three inputs and any device that have CCL peripherals will have a minimum of two LUTs available.

This napkinCAD sketch shows how [SM6VFZ] implemented the boost regulator in the ATtiny214. The AND gate is formed using one of the CCL LUT’s. The first “timer 1” on the left, connected to one input of the AND gate, is free running and set at 33 kHz. The analog comparator compares the boosted output voltage against an internally generated reference voltage derived from the DAC. The output of the comparator then “gates” timer 1 signal to trigger the second “timer 2” — which is a mono-shot timer set to max out at 15 us. This makes sure there is enough time left for the inductor to completely release its energy before the next cycle starts. You can check out the code that [SM6VFZ] used to built this prototype, and his generous amounts of commenting makes it easy to figure out how it works.

Based on this design, the prototype that he built delivers 12 V at about 200 mA with an 85% efficiency, which compares pretty well against regular switching regulators. Keep in mind that this is more of a proof-of-concept (that actually works), and there is a lot of scope for improvement in terms of noise, efficiency and other parameters, so everyone’s comments are welcome.

In an earlier blog post, we looked at how ATmegas with Programmable Logic came about with this feature that is usually found in PIC micro-controllers, thanks to Microchip’s acquisition of Atmel a few years back. But we haven’t seen any practical example of the CCL peripheral in an Atmel chip up until now.

Replacement LED Light Build Uses A Few Tricks

Microscopes have become essential work bench tools for hackers, allowing them to work with tiny SMD parts for PCB assembly and inspection. Couple of years back, mad scientist [smellsofbikes] picked up a stereo microscope from eBay. But its odd-sized, 12 volt Edison-style screw base lamp, connected to a 17 volt AC supply, burned off after a while. He swapped the burnt lamp with the spare, which too blew up after some time. Dumb lamps. Maybe the original spec called for 24 volt lamps, which were unobtanium due to the odd Edison screw base, but those would throw out a pretty yellow-orange glow. Anyhow, for some time, he worked with a jury-rigged goose neck lamp, but frequently moving the microscope and the lamp was becoming a chore. When he got fed up enough about it, he decided to Build a Replacement LED Microscope Light.

Usually, such builds are plain vanilla and not much to write in about, but [smellsofbikes] has a few tricks worth taking note of. He found a couple of high power, SMD LEDs in his parts bin. They were just slightly wider than 1.6 mm across the terminals. So he took a piece of double sided, copper clad FR4, and edge mounted the LED against one side of the PCB piece, twisting it slightly so he could solder both terminals. This works as a great heat sink for the LED while still having a very narrow profile. This was important as the replacement LED board had to fit the cylinder in which the original lamp was fitted.

The LED is driven by a constant current buck regulator, powered by the original 17 volt transformer. A bridge rectifier and several filter capacitors result in a low ripple DC supply, for which he used the KiCad spice functionality to work out the values. The LM3414 driver he used is a bit off the beaten track. It can run LEDs up to 60 watts at 1 amps and does not require an external current sense resistor. This was overkill since he planned to run the LED at just 150 mA, which would result in a very robust, long lasting solution. He designed the driver PCB in KiCad, and milled it on his LPKF circuit board plotter. The nice thing with CNC milled PCBs is that you can add custom copper floods and extend footprint pads. This trick lets you solder either a 0805 or a 1206 part to the same footprint – depending on what you can dig up from your parts bin.

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Custom Controller Makes Turbomolecular Pump Suck

[Mark Aren] purchased a pair of Turbomolecular pumps (TMP) sans controllers, and then built an FPGA based BLDC controller for the Turbomolecular pumps. A TMP is similar to a jet turbine, consisting of several stages of alternating moving turbine blades and stationary stator blades, and having turbine rotation speeds ranging from 10,000 rpm to 90,000 rpm. TMP’s cannot exhaust directly to atmosphere, and must be combined with a backing (or roughing) pump to create a lower grade vacuum first. They find use in lots of applications such as electron microscopy, analytical sciences, semiconductors and lamp manufacturing. With the lamp industry rapidly embracing LEDs, many of the traditional lamp making lines are getting decommissioned, and if you are lucky, you can snag a TMP at a low cost – but it still will not be cheap by any means.

The two BOC-Edwards EXT255H Compound Molecular Pumps (PDF), that [Mark] bought did not have their accompanying EXC100E Turbomolecular Pump Controllers (PDF), and given pandemic related restrictions, he decided to build a controller of his own, using components and modules from his parts bin. The pump and controller user manuals offered only sketchy details about the sensored BLDC motor used in the pump. The low phase-to-phase resistance implied low drive voltage, and [Mark] decided to try running it at 24 V to start with. He already had experience using the Mitsubishi PS21245-E IGBT inverter bridge, and even though it was rated for much higher voltages, he knew that it would work just fine at 24 V too.

After figuring out a state machine for motor commutation that utilized PWM based adjustable current control, he implemented it on a 128 element FPGA board. Considering how expensive the TMP was, he wisely decided to first try out his driver on a smaller “expendable” BLDC motor. This whole process was non-trivial, since his available IGBT module was untested and undocumented, and required several tweaks before he could run it at the required 12 kHz PWM signals. His test motor was also undocumented, failing to run correctly when first hooked up. Fixing that issue meant having to disassemble the motor to check its internal wiring. Eventually, his efforts paid off, and he was able to safely run the TMP motor to confirm that his design worked.

With FPGA code, IGBT wiring and power supply issues sorted, the next step was to add a supervisory micro-controller, using an Arduino Nano. Its functions included interfacing with a touch screen LCD as a user interface, communicating with the FPGA module, and controlling several relays to switch power to the motor power supply, the roughing pump, TMP cooling fan, and a solenoid for the vacuum vent. Spindle current is calculated by measuring voltage drop across shunt resistors on the low side of the IGBT. Motor speed is measured using one of the motor hall sensors, and a thermistor provides motor temperature sensing. [Mark]’s PCB fabrication technique seems a bit different too. Using an Excellon drill file, he drills holes in a piece of plastic using a laser cutter to create a bare board, and then solders copper tracks by hand.

His initial tests at atmospheric pressure (although not recommended unless you monitor pump temperature), resulted in 7300 rpm while consuming about 7 Amps before he had to shut it down. In further tests, after adding a roughing pump to the test setup, he was able to spin the TMP to 20,000 rpm while it consumed 0.6 A. Obviously, the pump is rated to operate at a higher voltage, possibly 48 V based on the values mentioned in the TMP controller manual. The project is still “work in progress” as [Mark] hopes to eventually drive the pump up to its specified 60,000 rpm operating speed. What is not clear is what he eventually intends to do with this piece of exotic machinery. All he mentions is that “he has recently taken an interest in high-vacuum systems and is interested in exploring the high-vacuum world of electron guns.”

Maybe [Mark] can compare notes with the Open Source Turbomolecular Pump Controller that we featured some time back. And if you’d like to be a little bit more adventurous and build you own TMP, we got you covered with this DIY Everyman’s Turbomolecular Pump.

Uncommon Bárány Chair Gets Fixed Up

Ever heard of a Bárány chair? Neither had [Troy Denton] before he was asked to repair one, but that didn’t stop him from rolling up his sleeves and tying to get the non-functional device back in working order. As it didn’t come with a user guide, manual, schematic or any other information, he had to rely on his experience and acumen gathered over years of practical work. Luckily for us, he decided to document the whole process.

While it’s not well known outside of aviation circles, the Bárány chair is an important piece of equipment in training pilots to get used to spatial disorientation. The device is essentially a motorized revolving chair, the idea being to spin the subject to induce disorientation. Rotation speed and direction can be controlled via a handheld wireless remote terminal.

When [Troy] first powered it up, the error code on the remote indicated “no power to base unit”. That turned out to be a quick fix – he simply had to move the power connection from a switched socket that had been turned off to a different outlet. But while that cleared the error message, the chair still wouldn’t rotate for any of the knob settings.

Manually rotating the chair showed the RPM on the remote, so [Troy] narrowed down his search to the motor related sections. The motor was being driven by a servo type signal, but changing the speed and direction knob on the remote didn’t seem to alter the control signal when he checked it with his scope. Opening up the hand held remote immediately uncovered the failed part – the rotary encoder for setting the speed and direction had physically split in to two pieces.

Since there was a clean split in the encoder, he was able to temporarily hold it back together to confirm that the chair could spin up. The cause was most likely “User Error” – the last person to conduct the test probably turned the knob rather enthusiastically. A new part is on the way, and the chair should be getting back to making prospective pilots dizzy in no time.

We love a good repair story here at Hackaday. Whether it’s patiently rebuilding a snapped PCB with bodge wires or coming up with replacement parts that may well be better than the originals, we never get tired of seeing a broken piece of gear put back together.

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Vintage Meters Reborn As Steam Punk Clock

[Build Comics], purveyors of comic strips “where tools are heroes”, have saved another pair of old, vintage, analog meters from the junkyard by converting them into a Meter Clock. The real heroes of the story are their trusty tools – Mac X the knife, Mr. TS the table saw and his trusty band of clamps, G. Rinder the angle grinder, Weldy the welder, Sharp Eye the marker, rounded up by Sandy the Sander and Jiggy Saw. The Drake & Gorham (London) meters going under the knife appear similar to vintage hardware from just after the end of World War II, such as this Ferranti Ammeter found at the Science Museum Group, making them at least 75 years old.

A small cam is used to engage the DST switch.

As you might expect, the conversion process is reminiscent of their previous projects. The original moving-coil movements are discarded, and the pointer is attached to a servo which will act as the new movement. Fresh dials are prepared to replace the original ampere markings with hours and minutes. To retain some of the original charm, the new dials have discoloration and blemishes replicated from the old dials.

The set screw which was once used to align the pointer with the zero mark on the dial is now used to activate a micro switch that enables daylight savings time. Two additional buttons provide a convenient interface to adjust the time. Precision time signals are derived from a DS3231 RTC module connected to an Arduino. A pair of seven segment displays are connected to the Arduino to make it easier to set the time. A piece of oak plank, surrounded by a metal angled frame, is used as a base for mounting the two meters so that the clock can be hung up on the wall.

If you’d like to build some more vintage inspired instrumentation, [Build Comics] have you covered with a Classy Weather Display or a Plant Moisture Gauge.

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