DIY IKEA Wireless Qi Charging for the Hexiwear


The Achilles Heel of the Mikroelektronika Hexiwear is its charging: the charging and USB connector are only designed for a limited number of plug-unplug cycles, and it does not have a wireless charging capability like the Apple iWatch. Until now! I have built a DIY wireless charging system for the Hexiwear πŸ™‚ :

Wireless Qi Charging the Hexiwear

Wireless Qi Charging the Hexiwear

Wireless Qi Charging? IKEA!!!!

I have been experimenting with wireless charing for a few weeks, including building a Qi charging station using a kit from Adafruit (see “Qi Wireless Charging Transmitter with 3D Printed Enclosure“). The problem is that getting Qi charging receivers seems not to be that simple. With my research I have found that the Apple iWatch is using Qi technology, but they tweaked it in a way that it only works with the Apple chargers/receivers (see “Apple tweaked the Qi charging standard so that Apple Watch only works with its own chargers“). Interestingly, the furniture company IKEA is selling Qi transmitters and receivers (http://www.ikea.com/us/en/catalog/categories/departments/wireless_charging/). To my surprise, when I visited a nearby IKEA store yesterday, the older iPhone and Samsung Galaxy S4 (VITAHULT) Qi receivers were on sale for CHF 0.95 (about US$1): what could be wrong with buying a few of them? At this point, I should probably mention the ‘rolling eyes’ of my wife ;-).

Treasure of Qi Receivers

Treasure of Qi Receivers

Opening

The question is: can I use these for my projects? So I decided to open up the wireless phone cover. The cover has to plastic parts, and with a bit tweaking I was able to separate them. Insider there is the battery connector, the receiver circuit and the charging coil under a black FFDM (Flux Field Directional Material):

VITAHULT open

VITAHULT open

The FFDM is a high magnetic permeability and low energy loss material which enhances the power transfer efficiency. The FFDM can be easily removed. Under the FFDM there is the receiver coil:

Removed FFDM

Removed FFDM

Removing Coil

The coil is glued to the plastic cover with a double side adhesive tape. I used a tooth pick to carefully lift it up:

Toothpicking the Coil

Toothpicking the Coil

Removing Board

Same approach for the board. Removing the board was a bit more difficult, the board is very thin and I did not want to damage it. At the end, both the coil and the board were separated from the back cover:

Removed Board and Coil

Removed Board and Coil

Backside of Board and Coil

Backside of Board and Coil

iPhone 4/4S Receiver

The above Samsung S4 receiver is rated up to 650 mA charing current. They had the iPhone 4/4S on sale for CHF 0.95 too which can charge up to 1000 mA:

IKEA iPhone 4 Qi Receiver

IKEA iPhone 4 Qi Receiver

Opening that case is best from the backside:

Open IKEA Qi iPhone 4 Receiver

Open IKEA Qi iPhone 4 Receiver

The coil is a larger one, and the receiver electronics are shielded with a piece of FFDM (?). As the coil is too large for the Hexiwear, I’m continuinig with the Samsung S4 receiver and coil.

Attaching Power Wires

I removed the battery connector from the receiver board and soldered wires to connect the Hexiwear docking station PCB (5V and GND to the battery charging circuit):

Charging Test Setup

Charging Test Setup

And voilΓ : I’m able to charge the device πŸ™‚ :

Qi Charing Works!

Qi Charching Works!

3D Printed Enclosure

The next step is to put everything in a 3D printed enclosure:

3D Printed Enclosure

3D Printed Enclosure

And is charging (not the charing icon on the Hexiwear) πŸ™‚

Qi Charging the Hexiwear

Qi Charging the Hexiwear

IKEA Charging Station

Best of all, it works with the IKEA Qi charging station too:

IKEA Qi Charging Station

IKEA Qi Charging Station

Yes, that works too: πŸ™‚

Qi Charging with IKEA Transmitter

Qi Charging with IKEA Transmitter

Summary

Sometimes a quick IKEA shopping can turn into something very useful outside the normal furniture world: I’m now able to use wireless Qi charging for the Hexiwear :-).

Happy Charging πŸ™‚

PS: A big ‘thank-you’ to my wife and daughters. They fully understand what it means to have an engineering family member. Well, at least most of the time….

Links

9 thoughts on “DIY IKEA Wireless Qi Charging for the Hexiwear

  1. Hi Erich,

    nice report. Sometimes it is helpful to be at the right place on the right time to have such a gold rush situation. As a comfort for your wife she is not alone. I wish you good luck for further shopping adventures like this, which end in an interesting DIY project.

    Michael

    Like

  2. Pingback: Adding an IKEA Wireless Charger to a Project | Hackaday

  3. Pingback: Hexiwear | Here's how make Hexiwear Qi charging compatible - Hexiwear

  4. at last, something of real worth from IKEA! πŸ™‚ better than grabbing a pot brush to feel you haven’t wasted 2 hours of your life! will be trying it myself..

    Like

  5. can i suggest something, if you wanted to make you own coil – self bonding wire. i form coils when doing R & D in my business from this type of wire on a temporary former. all you need to do is look up the math for the change in copper resistance over temperature. Run a current through it from a bench PSU with Constant current on, and hey presto, you could even have a optimised Hexagonal shaped coil..
    typical wire:
    http://www.elektrisola.com/self-bonding-wire.html

    Like

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