Year: 2017

Teenage Engineering The Raspberry Pi

September 5, 2017 by 22 Comments

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

September 5, 2017 by 10 Comments

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

September 4, 2017 by 14 Comments

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

September 4, 2017 by 13 Comments

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.

Continue reading “The (Robot) Body Electric” →

Hackaday Prize Entry: Elderly Autonomous Fall Detection

September 4, 2017 by 16 Comments

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.

Continue reading “Hackaday Prize Entry: Elderly Autonomous Fall Detection” →

The Day Six Spaceships Landed In England

September 4, 2017 by 36 Comments

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].

Tough Pi-ano Can Take A Punch

September 4, 2017 by 14 Comments

There will be no delicate solos for [24 Hour Engineer’s] Tough Pi-ano. It was built to soak punishment from aggressive youngsters in musical therapy, specifically those on the autism spectrum and those with Down’s syndrome. The Tough Pi-ano will be bolted to a wall with heavy-duty shelf brackets so it can’t fall on anyone. The keyboard is covered in plastic and it doesn’t have any exposed metal so there will be no splinters.

[24 Hour Engineer] made a short video demonstration and if you listen closely, he has a pun in all but one sentence. We love that kind of easter egg in YouTube videos. Check it out after the break.

Inside the 48-key instrument are four Raspberry Pi Zeros where each Pi controls one octave. The redundancy ensures that a hardware failure only drops out a single octave and the kids can keep playing until replacement parts arrive. Each Pi has identical programming and a thumbwheel switch tells it which octave it will be emulating.

Programming was done with Python and Pygame and all the inputs are run to a homemade “hat” where the wires are soldered. Pygame’s sole responsibility is to monitor the GPIO and then play the appropriate note when a button is pressed, slapped, punched or sat upon.

Similar in name, the Touch Piano has no moving parts or perhaps you would rather use your Raspberry Pi in an upright piano.

Continue reading “Tough Pi-ano Can Take A Punch” →