Pulse Necklace 11Oct2009
Hack Notes, Pulse Choker, Oct 11th 2009
Ironing Durability Test
Chung-Hay brought one of our old silver conductive paint prototype home and ironed it on the high heat mode for cottons:
I ironed through a towel as well as directly on the silver painted prototype. There was no melting or physical deformation. I even ironed on top of one of the three LEDs in quick sweeps.
We tested conductivity at today's Sensebridge meeting, and all LEDs lit. The ironing did not ruin the LED. The silver traces were conducting fine too.
In short, ironing silver conductive paint-based fabric will be fine.
Conductive Thread-based Prototype
I sewed us another prototype using conductive thread, rather than the silver paint. Both Eric and I like the look of the thread, though making this choker is more labor intensive. It'll be faster with a sewing machine...assuming I become competent.
To attach LEDs, Eric curled the legs into loops. Then I sewed the LEDs onto the thread traces like buttons. For the connection from the choker to the Arduino + board, I sewed jewelry hoops at the ends. The wires from the Arduino + board can be attached to clasps, which then hook through the hoops. However, for speed prototyping, we just soldered the wires to the hooks. We attached a 9V battery to power the circuitry. LEDs lit, and everything was functional! The blinking was still finicky - we'll focus on the signal processing later.
We learned that the weakest point for conductive thread is knotting. Two of the three hoops broke off, because the knots undid themselves. They stayed the second time around when we knotted many times over.
Overall, conductive thread works well as long as knots are tight and thread ends do not short each other.