Non-standard circuit boards

Non-standard Circuits: Jazz For Electrons

How creative are you when you make your circuit boards? Do you hunt around for different materials to use for the board? As long as it’s an insulator and can handle the heat of a soldering iron, then anything’s fair game. Or do you use a board at all? Let’s explore some options, both old favorites and some you may not have seen before, and see if we can get our creative juices flowing.

Transparent Circuit Boards

Let’s start with the desire to show more circuit and less board. For that we can start with [CNLohr]’s circuits on glass, usually microscope slides. What’s especially nice about his is that he provides detailed videos of the whole process, including all the failed things he tried along the way. Since he didn’t start with copper clad board, he instead glued his copper sheet to the glass using Loctite 3301. That was followed by the usual etching process, though with plenty of gotchas along the way.

In the end, he made a number of circuits, including an LED clock with the LEDs on the glass itself, and even attempted leading the community in making a glass keytar. The latter didn’t work out, but the resulting glass circuits are a work of art anyway.

What about making a transparent circuit board out of acrylic? [Frank Zhao] attempted just that by laser cutting troughs into the acrylic for the traces, and then drawing in nickel ink. But something in the ink ate into the acrylic, and as if that wasn’t bad enough, the voltage drop across the nickel was too high for his circuit. Suggestions were made in the comments for how to solve these problems, but unless we missed it, we haven’t seen another attempt yet.

But we’ve only just begun. What if you wanted even more transparency?

Continue reading “Non-standard Circuits: Jazz For Electrons”

Teenage Engineering The Raspberry Pi

The Teenage Engineering OP-1 is a tiny, portable synthesizer loaded up with 4-track recording, a sampler, sequencers, and a quite good synthesis engine. It also fits in your pocket and looks like a calculator built in West Germany. As you would expect with a synth/sampler/sequencer, you can save sounds, tracks, and other creations to a computer. [Doug] thought if you can connect it to a laptop, you can also connect it to a Raspberry Pi. He created an all-in-one storage solution for the OP-1 using only a Pi and a small character LCD.

The process of connecting the Pi to the OP-1 is pretty simple. First, plug a USB cable into the OP-1 and the Pi. Then, place the OP-1 into Disk Mode, the synth’s method of transferring files between itself and a computer. The Pi then synchronizes, changes the color of its character display from red to green, and becomes a web server available over WiFi where all the files can be accessed.

This is the bare minimum tech required to get files into and off of the OP-1. All you need is a bit of power and a USB connection, and all the files on the OP-1 can be backed up, transferred, or replaced without any other futzing around. It’s perfect for the minimalist OP-1, and a great example of how handy a WiFi enabled Pi can be.

Thanks [Pator] for sending this one in.

Coin-Sized LED Control

EE and firmware developer [Enrico] had played with LEDs as a kid, burning out his fair share of them by applying too much current. With the benefit of his firmware chops, he set about creating a board that drives LEDs properly.

[Enrico]’s project centers around a Texas Instruments LM3405 buck controller. It accepts input voltage from anywhere from 3V to 20V and outputs up to 20V/15W to one or more LEDs. He built a ton of safety features into it like short-circuit and open-circuit immunity, temperature control, and auto-off switching when idle. He also created a LED board to test the maximum efficiency of the driver. It consists of four Luxeon Rebel ES diodes, one each RGB and W. The entire back of the LED board is copper, with a monster heat sink attached.

You can follow along with the Glighter-S project on Hackaday.io, or you can buy one of his boards from his Tindie store.

We’ve covered LED drivers extensively in the past, with posts on a simple 10-watt LED driver and how to design your own LED driver.

RaspiReader, An Open Source Fingerprint Reader

In 2008, the then German interior minister, [Wolfgang Schäuble] had his fingerprint reproduced by members of the German Chaos Computer Club, or CCC, and published on a piece of plastic film distributed with their magazine. [Schäuble] was a keen proponent of mass gathering of biometric information by the state, and his widely circulated fingerprint lifted from a water glass served as an effective demonstration against the supposed infallibility of biometric information.

Diagram showing the fingerprint reader's operation.
Diagram showing the fingerprint reader’s operation.

It was reported at the time that the plastic [Schäuble] fingerprint could fool the commercial scanners of the day, including those used by the German passport agency, and the episode caused significant embarrassment to the politician. The idea of “spoofing” a fingerprint would completely undermine the plans for biometric data collection that were a significant policy feature for several European governments of the day.

It is interesting then to read a paper from Michigan State University, “RaspiReader: An Open Source Fingerprint Reader Facilitating Spoof Detection” (PDF downloadable from the linked page) by [Joshua J. Engelsma], [Kai Cao], and [Anil K. Jain] investigates the mechanism of an optical fingerprint reader and presents a design using the ever-popular Raspberry Pi that attempts to detect and defeat attempts at spoofing. For the uninitiated is serves as a fascinating primer on FTIR (Frustrated Total Internal Reflection) photography of fingerprints, and describes their technique combining it with a conventional image to detect spoofing. Best of all, the whole thing is open-source, meaning that you too can try building one yourself.

If [Cao] and [Jain] sound familiar, maybe it’s from their Samsung Galaxy fingerprint hack last year, so it’s neat to see them at work on the defense side. If you think that fingerprints make good passwords, you’ve got some background reading to do. If you just can’t get enough fingerprints, read [Al Williams]’ fundamentals of fingerprint scanning piece from earlier this year.

Via Hacker News.

The (Robot) Body Electric

If you deal with electronics, you probably think of static electricity as a bad thing. It blows up MOSFETs and ICs and we take a lot of pains to prevent that kind of damage. But a start-up company called Grabit is using static electricity as a way to allow robots to manipulate the real world. In particular, Nike is using these robots to build shoes. You can see a demo video, below.

Traditional robots use human-like hands or claw-like grippers to mimic how humans handle material. But Grabit has multiple patents on electroadhesion. The original focus was wall-climbing robots, but the real pay off has been in manufacturing robots since the electrostatic robots can do things that mechanical hands are a long way from duplicating.

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Hackaday Prize Entry: Elderly Autonomous Fall Detection

For his Hackaday Prize entry, [having11] is building a simple and cheap fall detection notification button that can be worn by senior citizens, young kids, or others affected by medical conditions. [having11] did some fact-finding, and it appears that falls are one of the leading causes of injury for seniors, according to data available from the Centres for Disease Control and Prevention (CDC).

This device will sense a fall and send a text message or email to a recipient caregiver, loved one, or friend. The notification can also be manually triggered using a pushbutton. There’s a 5-second delay before it actually sends the alert, allowing a false trigger to be canceled. On receiving the alert, the recipient can decide how to proceed and if the situation requires a call to emergency services.

The device uses an ESP8266, a MPU6050 MEMS gyro-accelerometer combo, and MyDevices Cayenne IoT service. The Cayenne IoT service is free for Makers and non-commercial use at the moment. The only other components needed are a few discretes and a small LiPo battery, keeping the cost of the device under $10. The whole assembly is housed in a 3D-printed enclosure. The next steps would probably be to make it more compact and design a housing that can be worn as an arm or chest band or on a waist belt. An important requirement of such monitoring devices is being able to notify when/before it is unable to fulfill its primary requirements. Towards that end, maybe adding a low battery and low WiFi signal strength indicators would be nice.

If you have more suggestions on making this better, chime in with your comments below.

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The Day Six Spaceships Landed In England

The BBC, as the British national broadcaster for so many decades, now finds itself also performing the function of keeper of a significant part of the collective national memory. Thus they have an unrivaled resource of quality film and audio recordings on hand for when they look back on the anniversary of a particular story, and the retrospectives they create from them can make for a particularly fascinating read.

This week has seen the fiftieth anniversary of a very unusual event, the day six flying saucers were found to have crash-landed in a straight line across the width of Southern England. It was as though a formation of invaders had entered the atmosphere in a manoeuvre gone wrong, and maintained their relative positions as they hurtled towards the unsuspecting countryside.

Except of course, there were no aliens, and there were no flying saucers. Instead there was a particularly resourceful group of apprentices from the Royal Aircraft Establishment at Farnborough, and the saucers were beautifully made fibreglass and metal creations. They contained electronic sound generators to give an alien-sounding beeping noise, and a fermenting mixture of flour and water for an alien-looking ectoplasmic goo should anybody decide to drill into them. The police were called and the RAF were scrambled, and a media frenzy occurred before finally the jolly hoaxters were unmasked. In those simpler times everyone had a good laugh and got on with their lives, while without a doubt now there would have been a full-blown terrorism scare and a biohazard alert over all that flour paste.

A Hackaday writer never admits her age, but this is a story that happened well before the arrival of this particular scribe. We salute and envy these 1960s pranksters, and hope that they went on to do great things. If you are a British resident you can see an accompanying TV report on their southern regional news programme, Inside Out, on BBC One South East and South today at 19:30 BST, or via BBC iPlayer should you miss it.

Flying saucer confectionery image: jo-h [CC BY 2.0].