In this instructable, we will be making a neopixel bike light to make your bike look cooler at night

you can either make connect it to your phone via WiFi or just with an Arduino nano and momentary button to switch through the modes

Sadly I cannot provide detailed images of the build process because I have already built it but I will do my best to explain how to make it using diagrams and some photos of the finished product

Supplies

A WeMos D1 Mini or an Arduino nano
A neopixel led strip
A switch
2 18650 lipo shells or a power bank
A battery charge and protect circuit capable of at least 1 A with a 5v output
A momentary switch (optional)
A case (it can either be 3D printed or made with something else)
A XH 1.25 JST 3 connector (optional)

Step 1: Deciding How You Are Going to Make It

You can either make it using the WeMos and through my app, control it from your phone with WiFi (if you decide to make this version there's is a bug in the code which cause the esp to close the access point making you have to restart the esp if you want to change the colour or the pattern )

Using an Arduino and a momentary button to cycle through the animations

I personally have chosen the esp method although the Arduino works great too

Step 2: Deciding What Case to Use

You can make this out of anything really (the first version was a caprice can for me)

what you need is either something that you can strap to your bike or something that can fit int the water bottle cage with a hole for the charging port and the switch(s)

I have now 3D printed a case for which I will be including a 3D file as well as the .step files if you want to customize them

if you 3d print the case on the bottom there is a slot for the connector, otherwise you can use dupont cables so you can easily take it off for charging if you use dupont cables then you must secure it with tape

Step 3: Led Strip Termination

Chances are that the led strip won't be properly terminated so when you solder the cables you must fill the hole with hot glue and if you have also put on a heat shrink

Step 4: Wire Up the Board

first wire up the batteries in parallel to the charger as shown here then connect the - to the - on the battery charger and the + to the + careful not to mess up the input and the output on the battery charge module

You will have to connect the 5v from the charge and protect module to the power switch both the board and the neopixel strip like it is shown in the diagram .connect the ground to both the board and the led strip.

For the WeMos connect the data pin to D2

And for the Arduino connect the switch to D4 and ground and the led strip to D6

Step 5: Uploading the Code

For the wemos we will be using code from bitluini where he initially used this code for home automation, I have modified it to work as an internet access point to which you connect to with your phone and change the colours from the app open all the files under one tab download all missing libraries and upload

for the Arduino, we will be using the buttoncycler sketch from the adafruit neopixel library

download all missing libraries and upload

IMPORTANT :

1)there currently is a bug in the code that makes it so the wemos closes its access point after 1-2 changes the colours or pattern making it so the strip effectively cannot change pattern unless you turn off and then back on the board

2)You will have to change the number of LEDs according to how many LEDs you neopixel strip has

For the wemos you will have to change const int LED_COUNT = 60; where 60 is the number of less on the strip

And for the Arduino, you will have to change #define PIXEL_COUNT 60 where 60 is the number of less on the strip