Hardware
The hardware giving functionality to the pillow consists of:
- Microcontroller - Adafruit QT Py
- Capacitive touch sensor - Bela Trill Craft
- Printed Circuit Board (PCB)
- Snap-wire connectors
The microcontroller and capacitive touch sensor are both commercially available and can be purchased online. The PCB has been designed for this project, but you can download the design files to have one fabricated for your own projects or even use KiCAD to edit the board to better suit your needs.
The snap-wires are how the PCB connects to the e-textile electrodes and they are built from basic parts.
Cut a length of wire about 2cm longer than desired final distance from the PCB to the textile electrode. 24 AWG is used in the workshops. Strip about 1cm from one end and twist into a ring.
Cut a 1.5 x 2cm rectangle of a thick fabric that doesn't fray like felt or neoprene.
Cut a 1.5 x 2 cm rectangle of conductive fabric with iron-on adhesive already applied on one side.
Sandwich the curled up ring of stripped wire in between the thick fabric and conductive fabric. Using a clothing iron, iron the conductive fabric onto the thick fabric glueing the wire in place.
Press fit a snap centring the ring of wire in the middle of the snap.
Strip about 0.5 cm from the exposed end of the wire. Weave the wire through the holes on the PCB for the selected pin. Keep the loops loose to make it easier to solder in place.
Once the wire is soldered, gently pull the wires so that they lie flat against the PCB.
