For our third project, Gabby and I worked together to create a LED twinkle zodiac constellation, based on the example given on learn.sparkfun.com We started with an outline of the design which we marked on a piece of thin black cloth, and decided which LED light color would go on each star marking.
We used conductive thread to attach the Lilypad coin cell battery holder and LilyTiny (connects the LEDs to the correct positive or negative circuit) to the back of the cloth, on the opposite side of the traced design.
Using the conductive thread, we began to attach the positive side of the battery cell to one of the positive holes on the LilyTiny. From there, we stitched the positive sides of the first three LEDs to the circuit on their respective spots on the front of the cloth. Some challenges we ran into included working with the conductive thread as it tended to tangle, and making sure the positive circuit stitches would not touch the negative stitches. We realized that it would be easier to navigate if we stitched the negative side first, so we started another thread at the negative side of the battery cell and TinyLily, and stitched the negative sides of each LED.
Once the negative side was completely stitched, we ran it back to a negative hole on the battery cell to complete the circuit, being careful to leave room for the positive circuit without crossing paths.
We continued stitching the positive circuit from where we left off on the third LED and finished the circuit back at the positive hole of the battery cell.
When all of the stitching was done, we inserted a battery into the cell, but none of the lights turned on. After checking the battery, we began to examine the circuit and figure out what could have gone wrong:
There are several spots on the negative circuit that may be too loosely stitched
It may have been necessary to divide up the positive side of the LEDs into smaller groups to connect back to the LilyTiny. Since we did not think of that when stitching the circuits, it may have caused an overload on the positive side.
As far as we can tell there are no spots where the threads may have overlapped or short-circuted, but to be sure Professor Meadows will take a closer look.