Electronics Assembly
Figure out how many pixels you need to wrap around the slippers. Mine fit 16 pixels each. Cut two lengths of LED strip to this length.
Cut the connector off the IN end of your NeoPixel strip. Usually this is the female connector, but verify you've got the correct end by looking for arrows on the strip itself -- they should be pointing away from the end you're working with.
Extend the red, black, and white wires by a few inches by soldering on a short length of wire to each. Cover the connections with heat shrink.
For the second slipper, solder these three wires directly to the copper pads on the strip: red to +, white to DI, and black to G.
If you need more help with this, check out our How to Solder NeoPixels guide.
The trickiest part of this project is preparing the force sensitive resistor (FSR). These little leads are delicate and hard to solder, and it's easy to accidentally melt the plastic so take your time.
Tin both pads with a blob of solder. Cut a couple of 2-3" long wires and tin the ends of each as well. Put the wire in place and gently melt the solder on the pad and the wire at the same time, then hold it very still until the solder solidifies for a firm connection. Cover the connections with heat shrink or electrical tape to protect them from pulling out.
Solder the two wires into the holes marked G and A0. Insert the wires from the NeoPixel strip into the screw terminal as shown: red to +5v, black to G, and white to NEO.
Plug the switch into the JST connector on the Feather, and plug the battery into the other side of the switch. Flick the switch to "on" and the LEDs should light up with a quick red, green, blue "startup" sequence.
Tap on the force sensitive resistor (FSR) and the LED strip will light up with a ripple effect in the colors you chose in the code.
Troubleshooting
If your strip isn't lighting up, here are a few things to try:
- Check that the pins you soldered to match the pins in the code. The FSR should be connected to G and A0, and the LED strip should be in the three rightmost screw terminals reading red, black, white from left to right.
- Be sure your battery is charged. Try plugging the battery directly into the JST port without the switch in between and make sure you get a status light on your board. If not, try powering from the USB port to see if you get different behavior.
- Try re-uploading the code. Check the serial monitor in your code editor to see if you're getting errors. ChatGPT or Claude can be helpful with debugging any errors you see.
- If you get a startup flash of red, green, blue but then nothing when you tap the sensor, then the sensor is likely the problem. Check to be sure you haven't bridged the pads with solder and that the plastic didn't get melted or the lines get broken. These things are super delicate!
- Be sure the wire connections into the screw terminal are secure.
Page last edited April 22, 2026
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