CO2 P@tch

How To Guide

Hello again all P@tch workshop participants!! It was so lovely to see your bright shining faces in Melbourne.

For those of you asking, You can find the free Arduino IDE software here  The free software will allow you to see the readings when you upload the code I have attached to this email. there is a great tutorial on how to get the circuit playground  up and running with Arduino here.

You will find the Arduino code for the two different iterations of P@tch here. The first file is without bluetooth but will allow you to see the sensor readings in real time when connected to your computer. The second file will let you connect to bluetooth. There is a full guide on setting up bluetooth here

List of Materials 

CIrcuit Playground Classic

On-board Buttons

On-Board 10 LEDs

SGP30 Gas Sensor 

Lithium Ion Battery


Micro Usb Cable

Conductive Thread


Embroidery Floss

5in x 5in Scrap of Fabric

Fingernail Polish


Circuit Diagram

Attachment to fabric

The microcontroller and bluetooth module both have unused connections. We will use embroidery floss to connect these components to the fabric patch by sewing through these holes. This will help keep the board from sliding around while we use our conductive thread to sew the circuit. 

Sewing The Circuit

Using conductive thread

Because it is made of stainless steel fibers, it will not oxidize like silver does: your projects will not ‘stop working’ because of oxidation after a few months and it’s safe to wash.

Threading the Needle

Cut a length of thread roughly the length of one arm. Much longer and the thread will start to be unwieldy and twisted. 

Use only one strand of thread

Thread a medium size needle with the conductive thread. You may need to moisten the thread end to help it stay pointy for threading.

Good Stitches to know: 

Running Stitch

Back Stitch 

Making Strong Contacts with Board

Get an idea of where your circuit will go. You may wish to mark traces with tailor’s chalk or a water-soluble embroidery marker, or just freehand it! Get your circuit board onto your taut fabric and pick up your threaded needle.

The thread must travel between components to connect them, while avoiding other paths of conductive thread in the circuit. The thread acts like uninsulated wire or traces on a circuit board, but this circuit board is made out of fabric

Bring the needle through the fabric from back to front, right next to the circuit board.

Pull the needle all the way through until it is stopped by the knot at the other end.

Bring your needle from front to back through the hole in the circuit board. Pull the needle and slack thread all the way through until the thread tightly makes contact with the conductive pad ad the edge of the board.

Repeat 4-5 times through the hole to make a secure electrical connection.

Now you can begin your running stitch toward the next component. 

Keep your stitches small (2-3mm in length) and neat throughout your circuit.

Keep power and ground lines FAR apart from each other. A short between power and ground will prevent your project from working and may even cause your battery to heat up.

Knotting off 

Tie a knot with a sewing needle! Insert the needle under a previous stitch.

Pull the thread almost all the way through, leaving a small loop. Put your needle through this loop and pull the thread through, creating a tight knot.

Don’t forget to seal the knot with Fray Check or clear nail polish before trimming the tail closely.

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