Get your bike ready for festival season!

This guide will detail taking an old Trek mountain bike from ordinary to Extra-blingbling! We'll decorate the heck out of it, add lights, and then waterproof and playa-proof everything so it's far less likely to break while you're riding around a festival at night.

We'll talk about different light strip options and code for maximizing battery life and brightness, project timelines and management, and how to make sure that all your connections are as bulletproof as possible, so you can ride with confidence.

It's already mid-June at the time of writing, and I already feel a bit behind on this project. I'll post progress pics as I go, and build the guide out as I encounter problems and pitfalls.  

Ready to go?

The very first step is to make a list of all the wondrous features you'd like for your bike. I talked to some longtime Burner friends and got a ton of great ideas.  I also made a Pinterest board with some fun ideas I'd like to try.

Essentials

• A good headlight for seeing in the dark
• NeoPixels on the frame so you can be seen
• A basket for carrying water and other stuff

Extras

• A tall tail-fin "flag" so you can be seen from a distance
• Daytime color -- paint, bling, and fun fur
• Audio sound system / bluetooth speaker

Pie-in-the-Sky Ideas

• POV Spoke wheels that show images as you move
• Multiple bikes synched together for group riding
• A "find my bike" feature that makes it blink in the dark from a distance

There are so many ideas to have. One feels almost attacked by the flock of ideas!

The planning stage is a great time to get realistic about what your essentials are, how much time you have, and what can be realistically done with a reasonable battery pack and budget.

For this project, I'm going to start with the essentials, then move to the extras if I've got the time. The pie-in-the-sky ideas probably should have been started September of last year, the day I got home from the last festival of the season, but I'll give some suggestions for after-market solutions you can buy.

I've ordered my LED supplies and enclosures from the Adafruit store! While I wait for the UPS guy, I'll start by decorating the bike. 

I want to paint the bike before I add lights, and then add bling and other exciting add-ons after the lights are on. 

The first step is to disassemble the bike as much as possible so I can spray paint the frame. I want to paint the basket also, so I left that in place. I started with a couple coats of white primer, so my fancy paint is a lot less likely to flake off.

I chose three anodized paint colors -- a brilliant blue, shiny purple, and metallic green. I want them all intermingling with each other and shining prettily. The label emphasizes that this paint looks best over metallic shiny chrome.. so my next layer of paint was shiny silver. I used Mirror Effect paint as well as regular silver paint to cover up the primer on the bike.

Finally, once the silver dried, I sprayed the three colors of metallic paint on, blending them willy-nilly so the bike has a flowing, gradient-style "mermaid" look to it. 

This stuff is really gorgeous. The photos don't quite do it justice. Painting over the silver really does give it a depth that I'm quite happy with.

Once the paint dried, I wanted to add some fun fur to the seat. I found a scrap of rainbow fur in my closet and glued it onto the existing seat with a generous amount of E6000. I didn't worry too much about getting a perfect "fit" -- there was no sewing involved, I just sort of draped the fabric over the top of the seat and then trimmed around the edges, making sure to get plenty of glue all around the sides.

I've got a lot more bling to add, but I want to wait until the electronics are in place before going any further. The UPS guy just knocked on my door, so the next step will be planning out where my lights are going and where to mount enclosures and batteries. It's also time to do some wiring diagrams and figure out exactly how to lay everything out.

Materials List

Adafruit Parts Used

• 3w RGB LED
• Feather M4 Express
• PropMaker FeatherWing with headers
• Waterproof 3xAA battery case with switch
• Female JST connector

Additional Parts Used

• Clear 1" and 3/4" heat shrink
• 1/8" Adhesive heat shrink
• 18" long 3/4" polycarbonate tube
• 5 1/2' long 1/2" polycarbonate tube
• Fiber optics & light pipe in varying sizes, at least 6' long
• Gaffer's tape
• Hot Glue

You'll also need a soldering iron & accessories, some ordinary heat shrink, and a heat gun.

The Vision

I want to mount something tall and striking to the back of the bike so I can be seen from a distance (and for ease of finding my bike among the crowd). This should be:

• Bright and tall -- maybe around 6-7 feet high
• Add motion when I ride
• Maybe create shade? A parasol attachment? Though this might be problematic with wind
• Removable, for bike transport

My first idea was to buy a rear bike rack and figure out how to use that as the mount for my "flag".  I bought one from Amazon (yes, okay, I bought the cheap one) and it absolutely didn't fit. The screws were the wrong length and the wrong width, the metal bars weren't nearly long enough, and the stabilizer mount simply wouldn't fit at all. After a frustrating morning, I've scrapped that idea and am trying something a little different. 

I went to the plastic store and picked up a couple of acrylic tubes that fit nicely inside each other. My idea is to create a fiber optic system, with bright lights mounted permanently to the bike, with the actual fiber optics removable for transport. This way I'll be able to add interest up high without having to string long wires or use connectors, which could break or allow corrosion into my system.

For fiber optics, I want something that will shine screamingly bright. We're just using one LED, so I don't need anything that does fancy animations. A 3W RGB LED will work perfectly for this project.  3 watts is a LOT of brightness! (Do not shine into remaining eye...) 

I'm going to make the fiber optic "tail feathers" a separate system entirely from the rest of the lights on the bike. 3W LEDs draw a lot of power, so I want to give them their own battery pack and controller. I like the idea of two totally separate systems, so if one system breaks or runs out of juice, I've still got another light system on my bike, and all is not lost.

My idea is to mount the 3W LED and microcontroller to the bottom of the outer 3/4" tube, then mount the whole assembly to the bike. The smaller tube will contain the fiber optics, and will simply slip into the larger tube when I'm ready to ride. This way I will be able to very easily disconnect the large tangly delicate fibers and put them INSIDE my car while the bike rides on the bike rack on the OUTSIDE of my car.

The RGB LED has 4 pads -- R, G, B, and +. The PropMaker Wing has matching pads in the center of the board. 

The PropMaker wing will stack on top of the Feather M4 Express, and the battery pack plugs into the Feather.

Important Note about Power!!

Do NOT leave the battery pack plugged in to the Feather while you also have a USB cord plugged in. The Feather has onboard charging, so it will try to charge your AA batteries, which could result in battery damage and / or Feather damage. 

Install CircuitPython

The Adafruit Feather M4 ships with CircuitPython but lets go ahead and update it to the latest version. It's super easy with the circuitpython.org website, just click the link below to launch the page. There you can choose to install stable release or beta. 

Quick Start

• Connect board to computer via a known good USB and double press the reset button.
• Download the CircuitPython UF2 and upload to the FEATHERBOOT drive.
• Open CIRCUITPY drive and upload the required libraries (listed below) and code.py

Adafruit Circuit Python Libraries

Download the CircuitPython library bundle and unzip the folder. Create a new folder in the CIRCUITPY drive and name it "lib". The following libraries are required to run the code properly. Double check to ensure all of the files and folders are inside the lib folder on the CIRCUITPY drive.

• adafruit_bus_device (directory)
• adafruit_lis3dh.mpy
• neopixel.mpy
• adafruit_rgbled.py
• simpleio.mpy

Upload code.py

Click the link below to download the project code. Save it as code.py on your CIRCUITPY drive.

Troubleshooting

If it's not working, make double-sure you have all the above libraries installed in your "lib" folder. Also be sure all your wire connections are tight and the wires are connected up correctly.

More about CircuitPython can be found here!

Important Note about Power!!

Do NOT leave the battery pack plugged in to the Feather while you also have a USB cord plugged in. The Feather has onboard charging, so it will try to charge your AA batteries, which could result in battery damage and / or Feather damage. 

Wiring

Next, stack the PropMaker Wing on top of the Feather M4 Express and solder in place. You can use female headers or just solder the PropMaker's headers directly to the Feather.

Playa-Proofing Your Electronics

We're going to use a couple different varieties of heat shrink to encase our electronics in plastic so they're 100% waterproof and dust-proof.

First up: Adhesive Heat Shrink

If you haven't used this stuff, well, it's great. Adhesive heat shrink already comes with hot-melt glue inside, so when you heat it up to shrink it down, the glue melts and makes a super strong, waterproof connection.  This stuff is really useful for playa-proofing your electronics.

Shop for Adhesive Heat Shrink on Amazon\

Next up: Clear 1" Heat Shrink

Heat shrink comes in GIANT size! A clear piece of 1" or 3/4" heat shrink sealed with hot glue at the ends will make a slim, cheap, waterproof enclosure for your electronics.

Once it's sealed, it's not easy to update code or fix loose connections, so be 100% sure everything is working the way you want before sealing. But, it is not too hard to remove the plastic for updates or fixes if needed. 99% alcohol will remove hot glue easily and completely, so if you need to get in there you can, without breaking your setup.

Shop for extra-large clear heat shrink on Amazon

Battery Case

Important Note about Power!!

Do NOT leave the battery pack plugged in to the Feather while you also have a USB cord plugged in. The Feather has onboard charging, so it will try to charge your AA batteries, which could result in battery damage and / or Feather damage. 

Once everything is completely encased and cooled, give it another test to make sure it's still working reliably. If you need to bust into this thing to repair a loose wire, or if you want to update the code, 99% alcohol will remove the hot glue. Just cut the heat shrink off then soak in alcohol and the glue will peel right off.

Your setup is now fully waterproof! I threw mine in the pool just to test it, and it's still blindingly bright at noontime in full sun! This will drive our fiber optics really well.

The 3W LED will get hot, but not hot enough to melt the glue. I imagine that you could break this if you really tried, but it would take some doing.

Note: this does make a waterproof light, but the battery case doesn't seem to be officially rated for underwater use, so .. I wouldn't put it in water deeper than a couple feet. "Waterproof" and "submersible" are not really the same thing. A battery case with a rating of IP68 would be certified submersible, but there's no offical rating on this one, so go carefully.

More about IP Ratings Here

The cool thing about this setup is that you actually get some variation in colors. The 3W LED actually has three LEDs inside: a red, green, and blue. Some of the fibers will be positioned directly above one of these lights, and some will be more generally placed, so you get a lovely color variation in your fibers.

I want to add lights to the frame that will animate in the same colors I painted the bike. I'm using NeoPixel strand lights at 2" pitch, for a couple of reasons:

1. They are already 100% waterproof -- each light is encased in plastic, and these lights are very hard to break
2. The strand-light style will allow me to wrap them around the bike frame, decorating it like a Christmas tree. I can get lights on all sides of the bike really easily.
3. The spread between the pixels means I can cover the whole bike using fewer lights than if I were to use a NeoPixel strip. This means my batteries will last a lot longer, since I'm driving fewer pixels. My hope is that this strip will last through several nights of use without having to change the batteries.

If soldering is not your jam, never fear: you can get this bolt-on kit for the Gemma M0 for attaching the lights and connectors to the board. Just wind the wires around through the Gemma's soldering holes and tighten the screws down to hold the wires in place. Dreamy!

In addition, you'll need:

• Large clear heat shrink in 1" and 1/2" sizes
• Wire strippers & wire cutters
• Hot glue gun
• Heat gun
• Small screwdriver
• Zip ties

Shop for extra-large clear heat shrink on Amazon

We'll wire the battery pack directly to the Gemma, since the waterproof pack doesn't come with a JST connector attached.  Red goes to VOUT and black goes to G.

The NeoPixels will use the same pads for + (VOUT) and - (G), and the third wire will attach to D1.  

MakeCode is Microsoft's ritzy drag-and-drop code editor. It makes it easy to get up and running with the Gemma M0. 

Find the Gemma M0 code editor at maker.makecode.com

Here's my completed project, which runs a green, blue and purple gradient along the LED strand. Click the Download link at the bottom, plug your Gemma M0 into your computer, click or double-click the reset button and drag the file onto the resulting GEMMABOOT drive. 

Or, follow along below to create your own project from scratch.

Code It Yourself

Head to https://maker.makecode.com and select New Project. Choose the Gemma M0 board. Give your project a name. I called mine Bike.

Note: NeoPixels are also called WS2812 pixels, and DotStars are called APA102 -- make sure you've got the right ones selected.

Next, drag an instance of strip set brightness into your on start loop.  Set the brightness to whatever you'd like. I want them as bright as possible, so I chose 255.

Hue, Saturation and Value

Hue, saturation and value are a means of defining a specific color using just numbers, on a scale of 0-255.

Hue refers to the color on the spectrum -- red, blue, purple, etc.  Red is at 0, blue is at around 140, purple comes in at around 180, and the spectrum loops around back to red at 255.

Saturation refers to how pastel or how vivid the colors are: 0 is a plain white, no matter what your hue is -- any completely unsaturated color just turns white.  255 is fully vivid and saturated with color. 

Value, for our purposes, refers to the brightness or intensity of the color. The higher the value, the more red or blue is added. 

You can read far more than you ever wanted to know about this on Wikipedia. What matters to us is that we can mess with the NeoPixel colors in all sorts of fun ways using hue, saturation and value.

Testing It Out

Almost there! We've created a customizable rainbow animation on our strip. However, I don't want a full rainbow -- I just want a partial rainbow, or a gradient animation. We can limit our hue variable to only show hues in one part of the spectrum using an if / then statement. 

We'll start with a hue of 80 (green), then increase by 2 until we reach 240 (magenta), at which time we will place a limit and tell the code to circle back around to 80.

Now the hue number will count up from 80 (since you set it to 80 in the setup block) by 2's, until it reaches 240, at which point it will pop back down to 80.  This effectively makes the NeoPixels change from green (80) to magenta (240) and then back again.  Success!  We've got our gradient. 

It's easy to change these values to get the color gradient you want.

Plug your Gemma M0 into your computer using a USB cable. Click the tiny Reset button in the middle of the board and the onboard pixel will turn green. When the lights turn green, a new drive will appear on your computer called GEMMABOOT.

In MakeCode, click the Download button to download your code to a file. Drag this file onto the GEMMABOOT drive.  That's it!  Plug in your light strand and make sure you love the animation. If not, go back and tweak it until you love it. Our next step will be to seal up the Gemma so you won't be able to easily change the code once you've done this.

Cut the female connector off the OUT end of your last NeoPixel strand. We'll attach this to the Gemma. Make sure you are cutting the correct connector off! NeoPixels only work in one direction -- you must attach the data wire to the IN end. On most strips, the male connector is on the IN end and the female is on the OUT, but double check your strips to be sure. There is a teeny tiny, very hard-to-see arrow on the back of the strips pointing in the direction of data flow.

Trim any extra fuzzy wires.

If you've already uploaded your code, plug your NeoPixels into the connector and be sure they come on. If they're not coming on, check to be sure the tiny power switch on the face of the Gemma is switched to ON. 

That's it for assembly of the electronics. We'll seal up the Gemma with heat shrink and hot glue a bit later, but the next step is to add the lights to the bike and run the animations in place, so you can be 100% sure you like them. A NeoPixel animation can look pretty different once the LEDs are wound around the bike frame, and once the Gemma is sealed we won't be able to update the code. Since we used a connector, we can add lights to the bike and test, then easily remove the Gemma and battery pack to seal it up.

Start by deciding where the battery pack and microcontroller will be attached. Mine will fit beautifully right underneath the bike seat, nestled up inside and out of the way.  From there, wrap the lights tightly around the bike. You have a lot of control over density -- you can cover most of the bike with just one strand, or snap together 3-4 strands for NeoPixel Overload. 

Be sure to avoid squishing any brake or gear cables -- go underneath instead of over so as not to interfere with the mechanics of the bike.

Turn the lights on and step back a few feet. Do you like the way the animations look wrapped around the frame? If not, now is the time to update the code until it's exactly how you want it to be. Next we'll seal up the microcontroller and connectors, so be very sure everything's working how you want!

Sealing it Up

Finally, use some hot glue to secure the sealed Gemma to the back of the battery case.  Now you can mount it to the bike -- but remember to mount it using zip ties or a bungee cord, or something you can remove fairly easily so you can access the battery pack when you need to change the batteries. I chose to leave this one connector uncovered with heat shrink, since that will make it much easier to get the battery case out. This case is a bit of a pain to open so I want to be able to take it off the bike entirely.

Even with all the sealing and robustifying you've done, it's possible that things will break, usually at the worst possible moment. Here's what's in my repair kit. It fits nicely inside an Adafruit box, and makes me the Hero whenever someone's lights aren't working on-site.

I've got a butane powered soldering iron which works without being plugged in. This thing is great for onsite repairs, or repairs for a bigger project that can't be moved to a power source. I also have a bit of solder, solder wick, and a cleaner sponge.

Pack extra heat shrink and zip ties -- these don't take up much room but will save you for sure. For this design I'll pack way more zip ties since I need to cut them to change the batteries.

Extra batteries are a great thing to put in your repair kit as well. And be sure you have a screwdriver that will open your battery case. I love this fancy versatile one - it's like 8 screwdrivers in one.

The Gemma M0 is so inexpensive, why not bring an entire second Gemma-and-battery-pack assembly? That way if something goes wrong you can just swap out the whole thing and not need to worry about fiddly repairs. Same with the LED strips -- these are easy to change out and plug in. You can re-heat shrink using your butane powered soldering iron or a lighter as your heat source. And if you don't use them this year, you will be glad you have them on hand for the next project!

A thread ripper from the craft / sewing store is more useful than you can imagine. Everyone should have one of these in their repair kit. It's a small razor blade that can slice through seams, heat shrink, mylar, or a variety of other materials without any danger of cutting your fingers or going through wires -- so, perfect for repairs that need to happen after your second beer. 

I always carry safety pins as well. A glue gun with extra sticks is really helpful too, though you'll need to find a place to plug it in as I've never seen a butane powered one.

Those little battery case screws are fiddly and small, and will get lost. Bring an extra battery case and some extra screws. Also throw in a roll of gaffer's tape (not shown) for when the zip ties won't cut it.

Go Further

In case this isn't enough, here are a few links to commercially available products that are playa-tested and approved!

• Monkey Lights: POV light kit for bike spoke wheels
• Fun fur in lots of weights and colors
• Kick stand so you don't have to lay it in the dirt
• Bike baskets in various sizes and shapes