LiPo batteries are a great power source for projects but they require care during use and charging. LiPo batteries can be a fire hazard if not handled properly.
Making the Fabric Friend
Duration
The time required will vary depending upon the complexity of the creation and the skill level of the creators. Two hours is probably a bare minimum to create a creature.
Materials
- Flora NeoPixels
- Conductive 2 or 3-ply thread
- Normal sewing thread
- Small needle
- Scissors
- Fabric of choice. Felt works well and is easier to work with.
- Stuffing material, like fiber fill
- Clear nail polish
- Alligator clip wires
Optional
- Fabric scissors (helpful!)
- Embroidery thread (for additional embellishment)
- Fabric glue (to hold NeoPixels down for sewing)
- Fabric pen or tailor’s chalk
Plan it!
Plan your friend. Sketch your plan, and be sure that the narrowest parts of the creation will still allow stuffing.You should also have an idea of where the Adafruit Circuit Playground Express and NeoPixels will be placed.
It’s important to also plan for where the battery pack will go. In your hand? Clipped to a loop? Lithium ion polymer (lipo) batteries can often be tucked inside a small pocket that you create in the project.
Cut out the paper plan, trace it onto the material, and cut out two versions. A fabric pen will fade away after an hour or so (or with rubbing). You can use a marking pen as well, but just be sure to cut inside the markings.
If the two sides of the friend don’t quite match, you can mark extra material on one, then trim it off.
Sketch your proposed wiring on paper. Remember that none of the lines of conductive thread can touch each other. The GND pins can service multiple NeoPixels, as can the 3.3V and VOUT for power. The Flora NeoPixels have arrows on them, and these should point away from the Adafruit Circuit Playground Express. Connect 3.3V to the positive side of the NeoPixel on the right, a pin from A0 - A7 in the center, and GND to the negative on the left.
If you are planning a number of NeoPixels in a chain, the GND and 3.3V / VOUT lines should connect all the way from the originating power or GND pin to every positive or negative loop on the NeoPixels. If you have to start a new piece of conductive thread on the needle, try to make this transition at the eyelet of the NeoPixel so you can loop it through a number of times and get a good contact between old and new thread. The middle signal thread will stop and start on either side of the NeoPixel (see below).
Be sure the arrows on the NeoPixels point away from the Adafruit Circuit Playground Express.
This view shows how the yellow signal thread that runs from a pin like A0, A1, etc. stops at one side of the NeoPixel and resumes on the other. This allows the signal to pass through the NeoPixel and give directions.
When you have drawn a plan that seems promising, test it with alligator clip wires. Make all the connections as you expect to make them with conductive thread, do your coding, and test. It’s much better to work out problems at this stage than after having invested time into sewing the lines incorrectly. Remember that the colors of alligator clip wires don’t matter in terms of functionality (they are all the same inside), but color coordinating helps keep you organized.
Sew on your board
Using traditional thread, secure the Adafruit Circuit Playground Express to your material. Use some of the pin tabs that you won’t need for the conductive thread.
To knot thread off, you can run the needle through a stitch on the back side.
Run the needle back through the resulting loop, repeat this process several times, and you will knot off the line.
Sew on the NeoPixels
Now that you have the Adafruit Circuit Playground Express securely fastened to the fabric, it’s time to use conductive thread to make the electrical connections. Using the wiring diagram you drew earlier as a guide, sew connections between the power, GND, and signal pin tabs. A simple running stitch works well. Take care that none of the lines of conductive thread touch each other. Also remember to end a line of stitching at the middle of a NeoPixel and resume with new thread on the other side.
You can use a single line of stitches that begin and end at eyelets on the hardware.
You can also use a double line of stitches. This is more work but makes a more reliable connection. If using this method, start sewing an inch or two away from the hardware, then sew to it, leaving a tail of thread hanging out of your first stitch.
Sew to one piece of hardware, then back to the other. At the eyelets, loop around the hole about three times, then run a stitch in through the loops, then go through the eyelet one more time. It’s vital that there be a solid connection at the eyelets.
Once you sew back to the starting place, you can use the tail you left sticking out to easily tie several knots. Add a dab of clear nail polish to help prevent it from unraveling.
The end result of either the single line of stitches or a double one should be lines of thread that make strong connections and that don’t touch.
For more on working with conductive thread and NeoPixels see a great video by Becky Stern of Adafruit:
https://learn.adafruit.com/flora-rgb-smart-pixels/add-more-pixels
Put the two pieces together
Sew the two pieces of fabric together. In the example Fabric Friend, the quadropus legs were sewn first because they would be the most difficult to stuff with fill. Sew and stuff them.
The whip stitch and the back stitch are two common ways of joining material. You have the option to join the two halves while reversed, then turn them inside out to stuff. This method makes most of the stitching invisible, but it is trickier and is not a good idea for beginners. If you do reverse your work, be sure to allow a big enough opening at the end to get the Circuit Playground Express itself out of the reversed inside. The sample quadropus was not reversed.
First, knot off your thread. See the video at 1:41 for tips on that and more:
When starting to join two pieces of fabric, begin inside one of them. That way, the knot is hidden.
The back stitch
This is a “one step forward, half a step back” stitch. You make a stitch, then come back to start the next stitch in the middle of the previous one. This forms a tight line of stitches that holds all kinds of fill well.
One step forward:
Half a step back:
The whip stitch
Come up through both pieces of material, then over the outside and back up again. Here, it would be up through red then yellow, then outside yellow and red, then back up through red then yellow.
If your fabric friend has small appendages, like the legs of this quadropus, stuff them before you keep going. Also, sew a simple pocket inside for your battery. Keep in mind that with the stuffing, it will tighten up.
Stuffing and battery
Here, a pencil helps push fill into a narrow leg. The battery pocket has also been sewn in.
Here’s a view of the end result with the battery pocket sewn to the purple (back) side.
View from back of battery pocket.
The thread has run out here, so it’s time to knot off the thread, and that’s best done inside the two pieces of fabric so that the knot won’t be visible. Push the needle through one layer, then exit through that same layer leaving a loop, then come back in through the loop. This will create a knot. Do that several times, and you’ll have knotted off the thread.
Stuff tricky parts of your Fabric Friend early, and leave a gap of at least two inches to insert the remaining fill.
Final Stitch
When you get to the end of your seam, use the method of leaving a loop in a stitch, then coming back through that loop with your needle to form a knot. Several of those will close up the seam.
To hide the tail, run the needle and thread through the body of the Fabric Friend. Compress it a little, then snip the thread. The tail will be hidden inside.
NEXT: Start coding!