Electronics Assembly
My bike has 27.5 inch wheels, and each spoke fits 36 pixels.
Figure out the length you want for your bike and cut 6 strips to that length. When cutting, leave the full width of the copper pads on the IN end of the cut-off strip. This will make soldering the strips a whole lot easier - these pads are tiny so do yourself a favor here and keep them intact.
Slip some clear heat shrink on to both cut ends of the strips. Don't shrink it down until you're done testing, but it's good to put it on now so you don't forget later.
The 6 clock pins (CI) on the LED strips will all connect to the same pin on the Feather: SCK.
Cut three yellow wires to about 5-6" long. Find the center, and carefully cut through the shielding on the silicone wires with your fingernail or a pair of wire strippers to expose a little bit of the wire in the middle.
Twist the three wires together so the exposed wires all snuggle together. You want a good solid connection of the metal here. Now you have six wires all neatly joined together. These six wires will connect to the CI pins on your six strips.
Cut one more 3-4" piece of yellow wire -- this one will connect all these wires to the Feather. Wrap it around the metal connection point so you have a seven wire bundle. Solder the connection thoroughly so all the wires have good connectivity. Cover the joint with heat shrink.
Repeat this process with the red wires - you want a 7-wire bundle there too. The 7th wire will connect to VCC on the USB breakout.
For the black wires, use the same technique but end up with 8 wires (so, 4 twisted pairs). The ground wires need to go to both the Feather G and the USB breakout G so we need one more in the black bundle.
For the green (data) wires: each LED pair will connect to a different data pin, so we need to keep them separate and not bundle them all up.
Make three 3-wire splice junctions. One wire from each set will go to the Feather (pins A1, A2, and A3) and the others will go to the DI pins on the LED strips.
Solder the wires onto the LED strips, making sure you're soldering to the IN end:
- Red > VCC
- Yellow > CI
- Green > DI
- Black > G
You should be left with three green wires, two black wires, one red wire and one yellow wire left unconnected.
Solder the red wire and one of the black wires to the USB breakout:
- Red > VBUS
- Black > G
Slide on some heat shrink, but again, don't seal anything yet.
Solder JST connectors onto the remaining wires: Black and yellow to the 2-pin connector, and the 3 green wires to the 3-pin connector.
I also ended up extending the wires leading to the USB breakout a bit just to give myself more wiggle room during installation.
Connect the other sides of the JST connectors to the Feather:
- 3-pin connector to A1, A2, and A3
- 2-pin connector to G and SCK
The order isn't too important for the 3 pin connector. We'll sort them out during installation. But make sure you get the G wire and SCK wire consistent with the LED wiring for the 2-pin connector.
Be sure you've uploaded the test code from the software page.
Plug the 3-pin and 2-pin connectors from the Feather into the LED strips. Plug the USB breakout into the battery. Also plug the Feather's USB port into the battery using a short USB cable.
If all goes well, your lights will turn on in red, green, and blue. Sort them out so the pairs are together.
Troubleshooting
This is a devilishly complicated wiring job. If all your lights come on in the right colors on the first try, I'd love to shake your hand! Mine sure didn't. If yours didn't either, here are some things to try:
- Look closely at the solder connections on the LED strips. These pads are SO tiny and SO close together that it's easy to bridge the solder, or have a stray wire from one pad touching another pad. With the power turned OFF, run a utility knife gently between the pads of the offending strip to see if there are any tiny stray wires.
- Make sure you soldered to the IN end of all the strips. If one is soldered on the OUT end (arrows pointing toward the solder joints), flip the strip around.
- If you had a hard time soldering, and the solder pads are burned or unsalvageable and you want to start again, cut off one LED from the front of the strip. If one or two of these strips have 35 instead of 36 in the length, the bike will still look great.
- Check all your connections again. Follow each wire through the connectors to make sure it goes where you think it goes. Some connectors have different color-coding order from other connectors and it's easy to accidentally plug the red wire into the black wire port on a connector from a different lot.
- Try re-uploading the test code. Open your serial monitor in Mu (or your favorite code editor) and see if the code is running correctly.
- Make sure both the USB breakout and the Feather are plugged into power, and that your battery is capable of running two ports at once. Try plugging them into a USB hub or wall socket to determine whether the battery is the problem.
Seal Your Connections. And Then Seal Them Some More.
I brought my bike to Burning Man on a very dusty and rainy year, and my project did not completely survive. Two of the strips started flickering on and off intermittently, and one of the silicone sleeves got torn somehow, either through riding or during transport - probably because I was too aggressive when tightening the zip tie.
When I pulled the JST connectors apart, there was playa dust inside both of them making the electrical connections much weaker. I also didn't seal the USB ports on either the battery or the controller. The bike did work for the first couple days of the festival but by the end I was experiencing problems.
This build will survive normal city use and forest or beach festivals, but for windy, dusty, muddy desert festivals I recommend adding a LOT more sealing.
Sealing Ideas
- Use a second layer of heat shrink over all wire connections. Squirt some hot glue inside the heat shrink before shrinking it down, or use heat shrink with adhesive already inside.
- Use a lot of self-sealing silicone tape. Bring an extra roll and really pile it on over the USB battery port connections. You'll need to cut it off to charge the battery, but your electronics will work a lot longer. All the connections I covered with this stuff DID survive!
- Wrap the JST connectors in self-sealing silicone tape as well to keep the dust out
- Be sure to seal up both ends of the LED strips. Two of my strips had exposed wire on the OUT end that I hadn't noticed during the build, and those were definitely giving me trouble after the burn.
- Be careful when attaching the strips to the bike! I got a zip tie too tight and it rubbed its way right through the silicone sleeve.
Page last edited September 16, 2026
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