For my Hexiwear university research project I’m exploring wireless charing options. I have built a DIY Qi charging station and created a 3D printed enclosure for it:

Qi Charging Transmitter

A weak point of the Hexiwear is that it needs a wire connection to charge the battery: either micro USB or with the docking station connector. That connector is fragile and subject to wear out: that connector is specified for 50 cycles (insert/removal) (see DF12(5.0)-30DP-0.5V(86) Spec Sheet) only!

Hexiwear Docking Station Connector

So why not using wireless charging?

Qi Charging Standard

Qi  (pronounced “chee” means “natural energy) is an interface standard developed by the Wireless Power Consortium for inductive electrical power transfer. It is getting popular for charging mobile devices. Adafruit offers a wireless transmitter hardware (https://www.adafruit.com/product/2162):

Qi Transmitter Board

The board takes 5V input (2A max) and is able to charge up to 5W. For the board and transmitter I have designed a simple 3D printed enclosure:

Qi Transmitter Enclosure Models

Below how to use it to charge an iPhone with a max charging input of 900 mA:

Charging iPhone with Qi

Some mobile devices already have a built-in charging receiver, otherwise a receiver can be added:

Qi Transmitter and receiver

I plan to add a LiPo battery to the charging station to have a true mobile charger. For the Hexiwear I have ordered a Qi receiver, but it is out of stock now. So not there yet, but making progress. Until I can charge the Hexiwear, I charge my mobile phone :-).

Happy Qi-ing 🙂

Links

• 3D files on GitHub: https://github.com/ErichStyger/Hexiwear_v2/tree/master/3D
• Qi description: https://en.wikipedia.org/wiki/Qi_(standard)
• Adafruit Qi Transmitter: https://www.adafruit.com/product/2162