Sunday, November 28, 2021

Sewing with Conductive Thread inTucson

 As the Christmas holiday approaches while our bus is parked in Tucson,  I found myself inspired to create an Arizona inspired e-textile project that can function as this year's Christmas hat. 

I started with a straw hat that I had purchased to walk around the desert with; the  decorative holes were begging for sewable LED's.   

I have aspired to learn how to use color changing Adafruit neopixels that  I've been carrying around for a few years.

I broke off 7 of them and considered where I might want to sew them on my hat. 

I also experimented with where I might want to place a micro-bit and battery pack
 so it would be comfortable and secure inside the hat.  The microbit would be used to control the lights using code.

Out came the alligator clips so I could attach the neopixels to the  the microbit 
and play with controlling them with block code (via MakeCode).  This was actually the first time I have used neopixels in a project.  I always felt intrigued but  intimidated by them.  
Thanks to the  Adafruit Uberguide to Neopixels, I started to understand them better.

I felt comfortable sewing conductive thread to the Ground and Power pads in extexile
but adding a third conductive trace through the DATA IN and the DATA OUT pads was new to me. 
It still baffles me how so much data can pass through a single piece of conductive thread through a series of neo-pixel lights. 

After some frustrating and unpredictable results when I experimented with
wiring the circuit, the code and neopixels. 

Eventually I  felt like I understood the circuit paths and started to use conductive thread 
to sew 7 neo pixels onto a piece of black ribbon. 

Unfortunately the final results didn't light up.  
No matter how hard I looked I couldn't spot the problem. 
Eventually I started to cut apart the black ribbon, but on a hunch, I  tested the 
circuits after each cut.

My hunch paid off, and after sacrificing two neo-pixels, the 5 remaining neo-pixels lit. 
I reworked my design to one with the 5 working neo-pixel strip and moved on. 

The next challenge was thinking how I might attach the three strands of thread to the microbit without shorting out the circuit from loose conductive thread moving around under my hat. 

The plan I came up with was to use conductive thread to sew a piece of fabric onto the microbit -  then add snaps to the fabric that were connected to the microbit via conductive thread. 
This would make the microbit removable to be used in other projects if needed. 
It also kept things soft and flexible.
Of course I tested to snaps in my basket to make sure they were conductive before sewing them on. 

I hit another obstacle when I came to attach the threads from the black ribbon to the snaps.

I could not see anyway to create a short circuit.  I came to the conclusion that I would need to insulate the threads to prevent a short circuit. 

I finally decided to make cloth channels for each piece of thread.  This insulated  the thread while keeping everything soft and flexible.   It was not pretty, but it worked.  I also chose fabric scraps that created a way to color code the (now hidden) wire to match Ground (black fabric scrap), Power (red fabric scrap) and NEOPIXEL data (multi-colored fabric scrap)

I'm almost embarrassed to post this one picture, but I  reminded myself that this was really a proof of concept prototype level project, and it was okay to forgo beautiful for functionality and focusing on my aspiration to learning to code and control neopixels. 

I tacked the black ribbon with just a few stitches - and when I was convinced that that the circuit worked with no shorts, I applied a layer of nail polish to  any exposed thread as an insulating layer.  Crossing my fingers that this would prevent shorts from happening as I moved around wearing my hat.
I grabbed some good old white thread, a glue gun, and velcro and did a quick job securing  everything in place before heading over to play with code. 

Next I started to play with the MakeCode environment and soon had written some code to control the 5 Neo-pixel lights. 
I was ready to continue playing with code, but the two empty pins on the microbit called for something. 

  So I grabbed a black ribbon and some red and white holiday decorations and added a festive looking band to the hat.     I added two simple sewable LEDS  which I attached to PIN 0 on the microbit.   This would allow me demonstrate the code needed to control straightforward external LEDS as well as NeoPixel LED's

I made sure they worked by adding a couple simple code snippets that would turn the little LED sequins off and on with button A and B 

And voila a physical computing project that has me vested enough to experiment with 
Microbit code.  

But wait -- there is one more pin left open.
I can't let that go unused. 

Considering that I also aspire to gain more creative confidence with sensors --
I think that this seems like the perfect use for that open PIN. 

I've received some interesting suggestions from my online network. 
More experimenting ahead -- 

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