Making good habits
So you're ready to make your wearable and you are going to start sewing with conductive thread, that's great! But you need to make sure you have these things done before getting to that point:
- Pick the right Conductive Thread
- Draw out the circuit and triple check the orientation of each component.
- Make sure you have a program that works that you've tested with
- Test your hardware and software before putting them in a circuit that's difficult to correct.
- Do not cross threads in a circuit unless you take protective measures - crosses will short your circuit.
There are several different conductive threads, but the main two types in textile projects are silver-coated nylon, and stainless steel thread made entirely of stainless steel.
Silver-coated nylon has a base of nylon, so it is most like regular thread when hand sewing the conducitve thread.
- Easy to work with due to flexible nylon core
- Cannot be soldered - the nylon base will not survive
- Varying amounts of resistance in different silver threads so this will need to be checked
Stainless Steel Thread
Stainless Steed thread is spun out of real steel fibers.
- Reliably low resistances
- Can be soldered
- The steel fibers grab onto fabric easily, so there is some skill involved to keep it untangled
Draw Out Connections Before Sewing
Once you start a project that has more than one or two components, drawing out your circuits becomes especially important. You can use these steps to draw it out:
- Lay out all the parts you're going to use on a blank piece of paper.
- Do any research you need in order to determine which pins should be connected.
- Draw the connections in the best way to minimize any crossing threads so that you have a guide to follow while you sew the components.
If you are using two different sides of fabric, (ie. a shirt with LEDs on the front, and the processor concealed on the other side of the fabric) make sure when you draw out your circuit that all components are oriented in the way they will be sewed.
I recently thought myself bulletproof with a wearable. I followed the golden rule of testing my program with hardware that I use for testing, and put brand new components into a circuit that was made with love, needle pricks, and a lot of time. I took extra time with every stitch to conceal my hardware and make everything look seamless, and did not test anything until every stitch was completed. When I went to upload my program, nothing worked and I had to trace back through my circuit and undo stitches and components until I was back to a working condition.
Always test the exact hardware that's going into your project so you don't end up getting frustrated and ditching your project! As you build your projects, try to plan simple tests along the way to get progress updates so you know when and where issues are if they occur. For example, if you're using 10 RGB LEDs in your project, test after each one is sewn into the circuit so you know if there are any shorts or other problems.
Get cables to simulate your threaded connections, and test test test.
Crossing Stitches without Shorts!
If you come to a point where you still have crossing stitches, there is a safe workaround.
- Make all the stitches necessary for the first thread.
- Find a spare piece of fabric.
- Sew the spare fabric on top of the first thread using regular thread that is not conductive. Make sure to note where the bottom fabric is mentally or by drawing it on the extra fabric.
- Keeping in mind where the first thread is sewn, sew the second thread on top of the extra fabric that is protecting the first thread.
Ta-da! Now you can build any circuit without worrying about shorts from unavoidable thread crossings!