Charliplexed Led E-textile Patch

April 15, 2011 by

Did you bring a hack? – (Spring of 2011 -Pre Maker Faire SF Bay Area)

Answering this question was the driving motivation in getting this project underway. After seeing several Charlieplex links on hack-a-day, I decided it was high time that I give it a try myself. I wanted something I didn’t have to carry around, so a T-shirt seemed like a logical choice. I had seen some other LED based e-textiles, but didn’t want to use huge 3mm or 5mm LED’s. Surface Mount Led’s came to mind, but I was not sure how to go about soldering anything to conductive thread.

Fortunately, I ran across an article describing how to mount surface mount LEDs to fabric by way of soldering small crimp beads to each end. This provided a place to loop the conductive thread through the LED.

First, acquire crimp beads and leds:

Seccond: Assemble

Each SMT led has a silver ring attached to it.

Next I had to decide how to design and control the Charlieplex.

The first step, was a prototype¬†circuit and layout. I really have to thank this guy [Ben] for posting helpfull information on the web. His 5×4 Charliplex display walkthrough provided me with the design I used to lay out the e-textile. I ended up taking his hand drawn schematic and using it as my t-shirt layout with minimal changes. I don’t have a printer at home, so I actually traced this schematic from a sheet of paper I placed over my monitor, and transferred that to the front and back of the fabric.

Then I added the conductive thread and components.


then I cut out a square, attached some connectors and an Arduino, and stuck it to a shirt!