Teardown and Repair of a Police Recorder

You should probably hope you haven’t seen [Techmoan’s] cassette recorder before. That’s because it is a Neal interview recorder that was mainly used by police to tape interrogations. This one was apparently used by the Royal Navy and was sold for parts. Turns out, the repair was simple, but the teardown and the analysis of the machine — you can see it in the video below — is pretty interesting if you’ve never seen one of these before.

The unit looks like a heavy-duty piece of industrial electronics from the 1980s. Unlike a commercial tape deck, this one is made to do one thing: record. You can’t even rewind a tape in it. Also unlike a consumer recorder, the Neal has a few special features aimed at making sure you didn’t miss some important confession on tape. First, it beeps if there’s no microphone plugged in. When [Techmoan] showed the recording head, we noticed it looked like it was split in half. Towards the end of the video, we found out why. In addition, the unit records two tracks: one audio track and another with a voice reading the elapsed time every 10 seconds — pretty high tech for its day.

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The Magic Flute of Rat Mind Control Aims to Mix Magic and Science

Well this is unusual. Behold the Magic Flute of Rat Mind Control, and as a project it is all about altering the response to the instrument, rather than being about hacking the musical instrument itself. It’s [Kurt White]’s entry to the Musical Instrument Challenge portion of The Hackaday Prize, and it’s as intriguing as it is different.

The Raspberry-Pi controlled, IoT Skinner box for rats, named Nicodemus.

[Kurt] has created a portable, internet-connected, automated food dispenser with a live streaming video feed and the ability to play recorded sounds. That device (named Nicodemus) is used as a Skinner Box to train rats — anywhere rats may be found — using operant conditioning to make them expect food when they hear a few bars of Black Sabbath’s Iron Man played on a small recorder (which is a type of flute.)

In short, the flute would allow one to summon hordes of rats as if by magic, because they have been trained by Nicodemus to associate Iron Man with food.

Many of the system’s elements are informed by the results of research into sound preference in rats, as well as their ability to discriminate between different melodies, so long as the right frequencies are present. The summoning part is all about science, but what about how to protect oneself from the hordes of hungry rodents who arrive with sharp teeth and high expectations of being fed? According to [Kurt], that’s where the magic comes in. He seems very certain that a ritual to convert a wooden recorder into a magic flute is all the protection one would need.

Embedded below is something I’m comfortable calling the strangest use case video we’ve ever seen. Well, we think it’s a dramatized use case. Perhaps it’s more correctly a mood piece or motivational assist. Outsider Art? You decide.

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Custom made MIDI recorder for an 8 year old girl

recorder

[KDM] over at The Controller Project forums let us know about a cool project he’s been working on: a MIDI recorder for an 8-year-old girl born with two digits per hand.

The recorder – a simple woodwind instrument usually made of plastic – is a staple of grade school music classes the world over. It’s an excellent introduction to the performing arts, but for those with two fingers per hand, the fingering is a little difficult.

[KDM] contacted a manufacturer of these instruments and they were kind enough to send over a half-dozen for his experimentations. He drilled out these recorders on a lathe and started work on a simple circuit to turn this recorder into a MIDI instrument. A simple PIC micro and a few buttons were used, with a DIN 5 port on the horn of the instrument.

The build works, but we’re thinking with a small electronic wind sensor, this instrument could easily become a full-fledged MIDI wind controller that could be easily and cheaply reproduced for other budding musicians with special needs.

Oh, one more thing. We’d like to give a big shout out to the giant dork who started The Controller Project. A lot of Hackaday readers know how to work a microcontroller and a soldering iron, so how about heading over to their forums and doing some good with your skills?

Steam fife

This auto-flute does it with steam. Well, electricity gets its piece of the action too as the tone holes are opened and closed using a set of solenoids.

We’re at a loss on how the sound is actually produced. We would think that a penny whistle has been used here, except if that were the case the solenoid nearest the kettle would have no use. Then again, after watching the demo after the break we’re not sure that it does have much of an effect. It may be meant to stop the sound but it doesn’t really work all that well.

At any rate we’d love to see some spin-off hacks. Assuming the plastic can stand up to the steam heat this would be a perfect robot controller for recorder controlled snake. You can get a recorder for a buck at the right dollar store, and solenoids can be made out of simple materials. If you know of a way to produce the sound yourself, all it takes are a few careful calculations to place the tone holes.

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Electronic recorder conversion

As we wrote the title to this feature we can see why [Jeff Ledger] calls it an electronic flute and not a recorder; this is a musical instrument and not something for archiving audio. Confusion aside, we’re all familiar with these plastic ‘musical’ instruments. Many elementary schools in our area require students to buy one as part of music class. So it shouldn’t be hard to find one if you want to try this for yourself (heck, [Jeff] grabbed his a the dollar store).

Basically, he’s replaced the finger holes with momentary press switches, then uses a Propeller dev board to turn the button presses into music. It’s simple and quick, but what does it for us is the breath actuator. Sure, you can set this up to play whenever a button is depressed, but [Jeff] went that extra mile and added a piezoelectric element to the bottom. When you blow through the instrument it flexes slightly, generating a tiny current that can be measured by the microcontroller. Check out the short clip after the break.

Do a little more work and you could turn this into some type of musical game controller. We’re thinking Zelda!

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Cheap audio equipment makes ATM theft easier

ATM information theft is nothing new. Neither is the use of skimmers to gain access to the data. But it’s a little surprising just how easy it has become to hack together the devices using audio equipment. The images above are samples of a skimmer for sale from an Eastern-European do-no-good. It is the magnetic stripe sniffer portion of the attack which captures card data as an audio recording. That is later turned into the binary code that was read from the card. We’re just speculating, but that looks an awful lot like the PCB from a pen recorder, something you can pick up for just a couple of bucks.

Of course this is used in conjunction with a camera to capture PIN data as the second part of the security protocol, but it really underscores the need for new ATM technology. Some skimmers don’t even require retrieval of the hardware, and you never know where the sketchy machines might pop up next.

[via Engadget and Slashdot]