Light Up Backpack Attachment

Have you ever found yourself bored with a very specific set of materials? Well, that's the situation I found myself in one day. So I decided to make something that would connect to my backpack and could be used as a sort of turn signal when riding my bike. So I guess ill be covering how to make that then.

The stuff you'll need to find yourself with.

Materials

1. 1 Circuit Playground Express (CPX) with included battery pack and cable
2. some neopixel LEDs. (the amount is based on how many lights you want)
3. A lot of wires
4. An a4-sized piece of felt
5. Some sewing string
6. Solder
7. flux (this is optional but makes it a lot easier)

Tools

1. A soldering iron
2. a wire stripper
3. A sewing needle

This step is relatively simple through slightly repetitive.

What you'll need for this step

1 neopixel

3 wires of different colors (they don't have to be different colors but it's easier to keep track of which ones are which.)

Solder

flux

1 soldering iron.

So for this step, all you have to do is to solder each of the 3 wires to a different connector. One to positive (+), one to negative (-), and one to input (in). The easiest way is to put the wire through the hole in the neopixel. Then put some flux on it if you have some. finally melt some solder on the iron and put in on the flux. (the flux should pull the solder to the wire) Now repeat this step for all the neopixels.

Now some tips for this step, Pre tin your wire (Example of how to do it). Next, if it is your first time soldering watch some tutorials on how to solder. (here's a good video that covers most types of soldering) Finally don't worry to much (it was my first time soldering while I made this project

For this step well need

Neopixels with wire (the ones we made in the last step)

Soldering iron

Flux

solder

For this step, we will connect all the neopixels together. The soldering will follow the same process as before. Though now we need to be more careful. Each wire needs to connect to a specific spot. So For the negative wire (-), we will connect it to the open negative spot. Then for the positive (+) wire, we will connect it to the Positive spot. Finally, for the input wire (in), we will connect it to the output (ou) wire. The last one in the chain should have one side open and the first one should have the wire not connected to anything. If you are careful this step should be easy.

For this step well need

The neopixel chain we made in the last step

Circuit Playground Express 

flux

solder

and finally a soldering iron

For this step well connect the neopixel strip to the Circuit Playground Express. For this connection, there is a very specific spot where you need to connect the wires. The negative wire (-) has to connect to the gnd, the positive (+) wire has to connect to VOUT, and finally, the input wire (in) has to connect to the A0 wire. If these connections aren't done correctly you could fry your neopixels. Once you connect the wires, the hard part will be done. (you can see how it should look in the second picture)

Things you need

Neopixel chain

Needle

Sowing thread

This step is relatively simple. All you need to do is to sow the cpx to the felt. This is really easy if you know how to sow. If you don't know then find a tutorial and just do like 2 loops on a pin.

Things you need

neopixel chain with felt

needle

seeing thread

This step is easy. All you need to do is to sow the wires together and to the felt. This can be done by doing a simple stitch a couple of times. This needs to be done for all neopixels.

For this step, we will code the neopixels. The software used is makecode by adafruit The first block of code sets up our neopixels. For my chain, I have 9 megapixels. But the amount will be based on how many you have. The second block of code makes it so that when you press the B button the neopixels will clear. The final block of code makes the neopixels have a gradient from blue to red. This code is super simple and only serves as an example. You can many other things such as a turn signal or using the acerloromiter to see when you break on a bike. Once you want to download the code all you have to do is download the code and drop it onto the Circuit Playground Express. (To connect the Circuit Playground Express  you have to plug it into your computer.)

Now your done. The way you mount the felt to your backpack or shirt is up to you. You can now bask in the glory of lights. Or you can give it as a gift. Cant tell you what to do.