A Shareable Wireless Biometric Flash Drive

Wireless storage and biometric authentication are both solved problems. But as [Nathan] and [Zhi] have noticed, there is no single storage solution that incorporates both. For their final project in [Bruce Land]’s ECE 4760, they sought to combine the two ideas under a tight budget while adding as many extras as they could afford, like an OLED and induction coil charging.

final_product_600Their solution can be used by up to 20 different people who each get a slice of an SD card in the storage unit There are two physical pieces, a base station and the wireless storage unit itself. The base station connects to the host PC over USB and contains an Arduino for serial pass-through and an nRF24L01+ module for communicating with the storage side. The storage drive’s components are crammed inside a clear plastic box. This not only looks cool, it negates the need for cutting out ports to mount the fingerprint sensor and the OLED. The sensor reads the user’s credentials through the box, and the authentication status is displayed on an OLED. Files are transferred to and from the SD card over a second nRF24L01+ through the requisite PIC32.

Fingerprint authorization gives the unit some physical security, but [Nathan] and [Zhi] would like to add an encryption scheme. Due to budget limitations and time constraints, the data transfer isn’t very fast (840 bytes/sec), but this isn’t really the nRF modules’ fault—most of the transmission protocol was implemented in software and they simply ran out of debugging time. There is also no filesystem architecture. In spite of these drawbacks, [Nathan] and [Zhi] created a working proof of concept for wireless biometric storage that they are happy with. Take a tour after the break.
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Custom Wireless Headphone Charging Station

wirelessHeadphoneChargingStation

We’ve come to expect quite a lot of convenience from our technology, to the point where repeatedly plugging in a device for recharging can seem tedious. Hackaday regular [Valentin Ameres] decided to ditch the plugs and built his own wireless headphone charger. We’ve seen [Valentin’s] work before, and one thing’s for certain: this guy loves his laser cutter. And he should, considering it’s churned out key components for a gorgeous Arc Reactor replica and his Airsoft Turret. [Valentin] fired it up yet again to carve the charging stand out of acrylic, then used a small torch and the edge of a table to bend the stand into shape.

He sourced the needed coils online and soldered the receiving coil to a spare miniUSB plug. These components are glued onto a laser-cut acrylic attachment, which fits against the side of the headphone and is held in place by plugging directly into the earpiece’s miniUSB jack. The headphones rest on the laser-cut charging stand, which has an extrusion of acrylic on one side that holds the emitter coil in position against the receiver coil. [Valentin] also added a simple momentary switch at the top of the stand to activate both the emitter coil and a status LED when pressed by the headphones.

Stick around for a video of the build below, and check out some other headphone hacks, like adding a Bluetooth upgrade or making a custom pair out of construction earmuffs.

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How about a nice game of Nixie chess?

[Tony] sent in a Nixie tube chess set he’s been working on, and we’re just floored with the quality of this build. The chess pieces glow without any visible wires, the board is extremely elegant with touches of gilding and brass, and extremely well designed using (mostly) materials and components contemporary to the old Russian Nixie tubes.

Instead of numeric Nixies, [Tony] chose IN-7 and IN-7A tubes originally made to display scientific symbols such as A, V, and ~. To power the these tubes, [Tony] used 64 air-core transformers underneath each square on the chess board, allowing these Nixie tubes to be powered just like an induction charger.

Even though his blog posts are a little thin on details, we’ve got to hand it to [Tony] for an amazing build. He says there will be a kit available that includes a gigantic PCB, but we wouldn’t hazard a guess as to how much that will cost.

You can check out a pair of videos of the Nixie chess set in action after the break.

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