Using a Standard Coil for NFC Tag Implant Reading

A few months ago Hackaday covered the xNT crowdfunding campaign which aimed at making an NTAG216 based NFC implant for different purposes. I actually backed it, found that standard NFC readers don’t perform well and therefore decided to try using a standard coil as an antenna for better reading performances.

Most NFC readers typically only have a small sweet spot where implant reading is possible. This is due to what we call coupling factor which depends on the reading distance and reader & NFC tag antenna geometries. Having a smaller antenna diameter increases the coupling factor and makes implant positioning easier.

In my detailed write-up you’ll find a good introduction to impedance matching, a process where a few passive components are added in series/parallel with an antenna to bring its complex impedance close to a RF signal transmitter’s. This usually requires expensive tools but allows optimal power transmission at a given frequency.

You may find our xNT coverage here.

Feed That Shoulder Boom Box with a Wrist Tune Transmitter

Next time you’re strutting down the block with that hi-fi on you shoulder, don’t subject yourself to the limitations of a radio station’s tight playlist or the short run time of a cassette tape. Pack your tunes on your wrist and beam them directly with this wearable FM transmitter. No wires… it’s like the future is now!

The Raspberry Pi has proven itself to be a dependable FM transmitter. This project follows in those footsteps but moves the goal line a few leaps further. The build has a full user interface which will make it easy to adapt to just about any application you can imagine. And the added twist is shown in the latter third of the video after the break. [Navic209] has included a microphone in the design which allows the wearer to transmit voice to an appropriately tuned radio. It gives the device a very Dick Tracey-esque feel.

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Prototype LED Light Suit runs off of a NES Power Glove

[Greg’s] been playing around with wearable hacks for quite some time now, and he’s decided to add a new twist for his latest LED light suit (Mk 4) — An ancient NES Power Glove to control it.

He was inspired by the band Hypercrush who had a music video where one of the guys was wearing a laser-shooting power glove — awesome. Having already made light suits before, he thought it’d be fun to do something similar.

The suit is controlled by an Arduino Pro Mini which has been hacked into the Power Glove for ultimate button pushing capabilities. He’s using 5 meter LED strips of the classic WS2812  RGB variety, which allow for individual LEDs to be addressed using a single pin. It’s powered by a 5V 2A USB battery pack, and he’s made all the components very modular, you could even say it’s “plug and play”!

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A Wrist-Mounted Flamethrower? Sure, Why Not?

There are three types of booths at Maker Faire. The first is the strange corporate booth, like Pepsi ‘revolutionizing fluid intake’ or some such nonsense. That one had the longest line of any booth, in case you’re wondering. The second type of booth is the people you would expect to be there – Atmel, TI, and Makerbot all came out in full force.

The third type of booth were a little hard to find. They’re the ‘show and tell’ spirit of Maker Faire, and [Stephen Hawes] was one of the best. Why? Wrist-mounted flamethrower, that’s why.

The flamethrower is fueled with a propane bottle originally meant for a camping stove, with a microcontroller and pot setup taking care of the height of the flame. Buttons underneath [Stephen]’s thumb takes care of the propane flow and tazer-based ignitor. The wrist measurement sensor can rescale to adjust the height of the flame to how far the wearer can move their wrist.

All in all, a great project for the Faire, although we did feel a little sorry for the NYC fire marshal that was assigned to [Stephen] for the entire faire. As an aside, we’re applauding [Stephen] for not referencing whatever comic book character has fire shooting out of his hand.

THP Semifinalist: B10N1C Yourself

The Hackaday Prize has had a few medical devices make the semifinalist cut, and of course wearables are on the list. How about implantables? That’s what Bionic Yourself 2.0 (or B10N1C) is doing with an implantable microcontroller, battery, and sensor system.

The hardware in B10N1C includes a electromyography sensor for measuring muscle activity, an accelerometer, a vibration motor, RFID reader/writer, temperature sensor, and – get this – a LED bar graph that will shine a light through the skin. That’s something we’ve never seen before, and if you’re becoming a cyborg, it’s a nice feature to have.

As with anything you would implant in your body, safety is a prime consideration for Bionic.the Lithium battery can be overcharged (yes, through a wireless charging setup) to 10V without a risk of fire or explosion, can be hit with a hammer, and can even be punctured. The enclosure is medical grade silicone, the contacts are medical grade stainless steel, and there’s a humidity sensor inside that will radio a message saying its time to remove the device if the moisture level in the enclosure increases.

Because the device is implanted under the skin, being able to recharge and update the code without a physical connection is the name of the game. There’s a coil for wireless charging, and a lot of work is going into over the air firmware updating. It’s an astonishing project, and while most people probably won’t opt for a cyborg implant, it will look really cool.


SpaceWrencherThe project featured in this post is a quarterfinalist in The Hackaday Prize.

THP Quarterfinalist: WALLTECH Smartwatch

While there is lots of hype about a big company launching a new wearable product, we’re more interested in [Walltech]’s open source OLED Smartwatch. This entry into The Hackaday Prize merges a collection of sensors and an OLED screen into a wearable device that talks to your smartphone over Bluetooth Low Energy.

The device is based on the IMUduino BTLE development board. This tiny Arduino clone packs an inertial measurement unit (IMU), a Nordic nRF8001 Bluetooth radio, and an ATMEGA32u4 microcontroller.

The 1.5″ OLED display comes from [miker] who makes an OLED module based on the SSD1351. A STP200M 3D pedometer provides activity monitoring in a tiny package.

On the hardware side, packaging all these components into something that will fit on your wrist is quite difficult. The prototype hardware is built from mostly off the shelf components, but still manages to be watch sized.

At this point, it looks like the code is the main challenge remaining. There’s a lot of functionality that could be implemented, and [Walltech] even mentions that it’s designed to be very customizable. It even supports Android; the Apple Watch can’t do that.


SpaceWrencherThe project featured in this post is a quarterfinalist in The Hackaday Prize.