Begin tightening the knob on the outer ring and also pulling the fabric taut in the hoop.
Thread a needle with 2-ply conductive thread and pierce the fabric from back to front next to the pad marked D6 on FLORA.
Leave a 5" tail at the back of the fabric and make a few stitches through the D6 hole, securing it to the pant leg.
Learn more tips over at our Conductive Thread guide!
Knot and seal at the back, then cover the snap by folding the fabric in half.
Stitch two lines as shown in plan thread, creating the shape of a fin. Cut off excess fabric about 1/4" from the seam and turn the fin right side out.
You should have a long piece of conductive thread coming from the inside of the fin.
Line up the snap on the fin and snap together, then stitch the fin to the body with plain thread.
Pick up the conductive thread tail coming out of the fin and use it to stitch a path to TX (aka D1, or any digital pin) on FLORA.
These two parts will serve as a switch, detectable when you snap and unsnap the fin.