My intention was to create a functional, reasonably stylish (meaning, not so ugly I would never wear it), self-contained bag filled with programmable LEDs. The bag is designed to hide the battery, controller board, wires and LEDs, while being durable enough to survive the inevitable bumps, rubs and bouncing around you experience in crowded clubs and dancefloors.
The electronics are removable, in case any of it needs to be replaced. Since it uses an arduino compatible controller board, it is easy to reprogram for any occasion. There is also a switch wired into the bag, so you can include changes to the pattern or colors in your program.
So if you want to draw attention to yourself, and be the life of any event, follow along with me and have your own super bright party bag!
I must give many, many thanks to Erin St. Blaine, for writing her Animated Neopixel Glow Fur Scarf Tutorial (https://learn.adafruit.com/animated-neopixel-gemma-glow-fur-scarf/materials). If you browse her tutorial, you will find many ideas of hers used in my project. I liked her code, so that is what I used to control my project. Since I used her code, I needed the same wiring layout, and used the membrane switch she did. Some other parts of it were just fantastic ideas I incorporated.
Step 1: Tools and Materials
Since you can probably find a suitable bag to use for this, avoiding the need to make your own like I did, I have seperated items into sections for the bag and electronics respectively.
Fabric - I used less than half a yard each of black lightweight canvas and broadcloth cotton. You may need more if your design is larger than mine. Fabric stores have the best selection, scrap fabrics work great too!
Thread - I used black upholstery thread. General purpose thread should work as well. Fabric stores have it, anywhere with a craft section will too.
No-sew Heat n Bond Tape (optional) - not necessary, but useful for some seams. Any place with fabric should have this as well.
Hot Glue Sticks - Appropriate size and temperature for your gun. Available wherever glue guns are sold.
Eyelets - I had 5/32" eyelets. Make sure they are big enough to show the LED light through them. You need to have one for each LED in your design, a few spares are helpful. Head on down to the craft or hardware store.
Grommets - I used 3/8" size. Ensure they are compatible with your grommet tool, and can fit your wire connections through them. I only needed two. The hardware store has got them.
D-Rings - I used two 3/4" rings to attach the strap. Craft store will have them.
Strap Material - Thin enough to fit in your D-Rings. Fabric stores have a wide selection of sizes and colors. Get enough for your desired strap length, plus at least half a foot extra to attach to the bag.
Sliding Buckle - Only necessary if you want an adjustable strap. Appropriate size for your strap. Craft store for this too.
Sewing Machine - Nothing fancy needed here, all you will need is straight stiches. Don't forget your bobbins! Mine was from Wally World, fabric stores carry them as well.
Fabric Scissors - A good, sharp pair will make all your fabric cutting easy and enjoyable. A rotary cutter will also work fantastically. Fabric stores will have these.
Clothing Iron - For pressing seams and heating no-sew strips. Department stores will have an inexpensive one for you.
Hot Glue Gun - mine is a high temp model, low temp is still usable. Used to diffuse the LED lights, and secure electronics. Grab one from a craft store.
Eyelet Tool - For securing eyelets to the fabric. I used the Dritz brand eyelet pliers (best eyelet pliers I've found), available at most craft stores.
Grommet Tool - I used a 3/8" size hammer and anvil style tool. Available at your local hardware store.
I'll mention now, nearly every electronic component was purchased from Adafruit.com. I'm a big fan of their business plan, to educate people first and foremost. They're also big on workplace equality, which is also fantastic. There are many alternatives from other suppliers, but I personally choose to support companies with a business plan I agree with. Unless otherwise noted, I probably got it from Adafruit.
Adafruit Gemma Microcontroller - The brains of the operation. You can use most any arduino compatible microcontroller, such as a Trinket or Arduino Mini. There are many other options which give more capability as well, but I wanted something simple and cheap. I chose the Gemma over the Trinket because it had a JST power connector already soldered to it. (https://www.adafruit.com/product/1222)
Individually Programmable LEDs - I used these Neopixel 5050 LEDs from adafruit. I chose them for their small profile, and ability to design my own layout. They are fairly inexpensive, but as with most things, reducing the cost by half generally increases the work by four or more times. These are intended for surface mount applications, so soldering them to wires is a bit difficult (but possible, with care). Other, easier options include the PCB Neopixels, the Flora Neopixels, or any of the various shapes and strips of addressable LEDs on the market. My design calls for 62 LEDs, but I got extra just in case I messed any up, or received duds. (https://www.adafruit.com/products/1655)
2500mAh LiPo Battery - I went with a Lithium Polymer battery, because they are small, lightweight, and pack a lot of power. They require more care, so you can use Lithium Ion, or AA battery packs, as long as you don't mind some extra bulk. Don't forget a charger if you need one. (https://www.adafruit.com/products/328)
Membrane Switch - This one is small, and just the right size for me. This is to tell the program to switch color patterns. (https://www.adafruit.com/product/1333)
On/Off Switch - I connected this to the battery, so I could easily turn the lights on or off without unplugging the JST connector from the controller. (https://www.adafruit.com/products/1092)
Wire - Since the pads on the LEDs are so small, you will need a small guage wire. I used 28ga stranded, but solid core is fine for most of the connections. The wire won't be flexing. Bought at my local electronics store.
Solder - It is best to use a lead based solder for this project. I used 60/40 rosin core, in 5mm and 7mm thicknesses. Lead free solder needs too high of a temperature to flow, and will damage the LEDs plastic casing. I got this from my local electronics store as well.
Plastic Sheet - I used this to give a stiff backing for gluing my lights to. I cut a piece from the lid to a cat litter bin, hopefully you can find something.
Soldering Iron - Use a decent one, with a fine pencil tip (a small chisel tip is also helpful). The iron should be 25w minimum. I have a basic 40w weller. A soldering stand is a good idea, but choose your own methods. I'm not the one getting burned, you are. At least have a way to clean your tip. Available at hardware and electronics stores.
Wire Stripper/Cutter - Needs to strip small wire, 28ga or finer. Also available at hardware and electronics retailers.
Multimeter - To check your circuits. Use one with a continuity setting. Again, hardware and electronics stores will have these.
Hot Glue Gun - Same one as above, to secure components (cause I go high tech here, lol).
Helping Hand/Magnifier (optional) - I did not use these, but you may find them helpful. I felt they slowed down the process of soldering around 250 connections, but they may work for you. Every electronics store should have them.
Step 2: Plan Your Design
I included pictures of my final LED layout, as well as the template I used to mark the seam allowances. I don't mind if anyone uses my design, but I do think it's better to design your own and make it unique to you. That's why we make stuff, right?
I had a basic idea of what I wanted the LED strips to look like, but that was about it. Since I was making it to be functional, I had to think about what I would be carrying (phone, wallet, keys, etc.), and measured all those to make sure I allowed enough room. I also knew I wanted the LEDs to be hidden, shining through holes in the fabric, and figured mounting them to a removable backing would fit the bill, so I needed to plan a pocket to slide the electronics into.
Many do it yourself bags are just sewn flat, assuming the bag will expand to fit things. since I didn't want much pressure on the electronics, nor did I want the front to bulge and distort the pattern, I decided to add some depth to the bag, to eliminate strain on the delicate electronics not included in most bags. My dimensions came out to be 6.5" wide, 7.5" tall, 3/4" deep on the finished bag. I also wanted a liner in the bag, so I planned for that as well.
After deciding on the dimensions of the bag, I drew them down onto the graph paper so I could scale the LED pattern to the appropriate size. I started with lines to indicate my strip shape, so I could determine the spacing I liked for the LEDs. I went with a 1/2" distance, by length of the line, so the LEDs appeared more evenly spaced along the curves.
Then I planned where the electronics would go. I placed the controller first, taking into account the necessary wiring. I knew I needed a pocket for the battery, so I designed that. At this point, I thought about placement of the switches and how to run the wiring for those.
Next, I had to sketch out the pieces I would be cutting out of the fabric. I added half an inch on each side for seam allowances. I needed three pieces of canvas and two pieces of broadcloth 8.5" by 7.5" for the front and back panels. For the sides and bottom I would need two pieces of canvas and one piece of broadcloth, all 23" by 1 3/4". I also needed a small piece of canvas to create the battery pocket, so I laid my battery on my graph paper, and drew a rectangle with enough distance around the battery to construct a pocket. I made pattern templates for the front/back pieces and the pocket, but just drew the side/bottom pieces on the fabric with a yardstick.
Step 3: Cutting the Fabric
After you wash the fabric, you can lay out your templates and trace around them. I just used a white fabric pencil for the canvas, and a purple fabric pen for the magenta broadcloth, because that's what I had on hand. I also used this opportunity to mark out my seam allowances, so I also had my sewing lines marked out. I didn't take pictures before cutting, so imagine some rectangles on fabric, the exact shape and size of the pieces needed.
You can see the style of template I use to mark my seams in the second picture. It looks kind of like a T. This is the method I used, because it lets me precisely center the template, and allows me to mark all corners, and I fill in any missing lines using a straightedge. I doubt it's the tried and true method one would learn if they took sewing lessons, but it worked for me.
Next, I grabbed my fabric scissors (being careful not to run), and cut the pieces out. I then marked where the battery pocket would go on one of the front pieces of canvas, and cut a line across the top of the pocket area, with small perpindicular slits on either end, making two flaps, which will be used to create a "door" into the battery pocket. Make sure it's big enough to easily slide the battery through.
Step 4: Preparing for Sewing
First I finished up the hole for the battery pocket. Press your seams with a hot iron, and cut some of your heat n bond strips to the appropriate length. Follow the instructions on the packaging to make these seams. You can just sew this seam, but I chose the easier method, since there will be no strain on the seam.
Next we need to mark where the LEDs will shine through the fabric, to place some eyelets. I used my paper template, poked holes with my white fabric pencil through the center of each LED location through to the fabric, and twisted it around to mark a bunch of dots. I then used an appropriately sized circle stencil to mark where my eyelets would go, so I could cut holes for them. The holes need to be slightly smaller than the eyelets, so they grip the fabric well when you crimp them. You could use a fabric punch to make the holes, but I couldn't find mine, so I used a pair of scissors to cut them out.
Next, we will attach the eyelets. If you look at the pictures, you will see I didn't cut all the holes before adding eyelets. There is no reason for this, I just got bored cutting holes and wanted to do something else, so I crimped eyelets. Just follow the instructions on your eyelet tool to crimp them down onto the holes, and you're good to go. Since we're using eyelets, make sure the rounded sides are all facing the same direction. The back of crimped eyelets looks bad, so we want to hide those.
After all the eyelets are in place, we need to create a final template for our LED layout, on the plastic backing the LEDs will be glued to. I cut the plastic backing piece from the lid of a cat litter bucket, since it was free, and the stiffness I wanted. I made it the size I needed to slide into the pocket we will create to hold it, which is slightly smaller than 7.5" by 6.5". I just used a fabric template, and cut a little bit inside the lines. Next I placed the eyelet covered fabric centered over the plastic, so it sits in the same position it will when the bag is finished, and taped them together. Using a fine tipped permanent marker, I marked where all the eyelets were. Odds are, the eyelets are slightly off from the exact placement on your original design. It's not much, and doesn't look bad, but it will help to know the exact layout when we glue the lights to the plastic backing. I also made a reverse pattern on the back of the plastic piece, which will be used later when the LEDs are soldered together. I used the same process for this, just with the fabric flipped over so back of the fabric faced up.
This could also be a good time to drill a hole in the plastic, to place the controller board. I did this so the board didn't push on the fabric very much. It's also wise to cut out notches at the connections on the controller, especially the jst plug, so there's room for the wires. I put mine in the upper left corner.
I also cut a piece of cardboard the same size as the plastic backing. I used this to simulate the added thickness of the LEDs, which we will add to the plastic later. You can tape the cardboard to the back of the plastic now if you like, just make sure the front side of the template is showing.
Now we will add some grommets, so there are some finished holes for the switch wires. These will not be visible when the bag is completed, so the color doesn't matter. One grommet will be placed on one piece of the side/bottom canvas, near one end. leave a minimum of 1" from the end for folding the seam. The other grommet will go on the canvas with the battery pocket, above the pocket. The grommet on the pocket piece will line up with a hole in the plastic, so it's wise to ensure it will not interfere with LED placement. You can see in my picture, I accidentally put a grommet below the pocket, instead of above. This was an easy fix, since the mistake will not be visible. I just put another grommet in the correct location. Learn from my mistake, and double check what you are doing. I had already attached the pocket by this point, but I will explain that in the next step.
Finally, I squirted hot glue into the eyelets on the front piece of the canvas. This was to create light diffusers. I simply laid the fabric on a sheet of parchment paper, and filled the eyelet with hot glue. To prevent those hot glue spiderweb hairs, I just pull the tip of the hot glue gun away from my dab of glue a tiny distance, and circle around the dab until the hair breaks off and melts into the glue dab.
At this point, you could attach the D-rings to the canvas sides, but I chose to hand sew them later.
Step 5: Sewing It All Together
I assume you know how to use your sewing machine, so I won't explain that. However, I do want to remind you to start and end every row of stiches by going forward 3-5 stitches, reversing the same amount of stiches over your starting ones, and proceeding from there, to lock your stitches. You can also use the self-locking stitch if your machine has that option.
First, I pinned together the battery pocket portion. You can see in the first picture the small pocket piece has the sides pressed in such a way that it will have a little depth when sewn. I did not do this with the top and bottom because I did not want square edges, so items going in and out of the bag would slide by better, if they contacted the battery pocket. Ensure you place the pocket so you are not sewing over the heat n seal seams, that stuff will mess up your needle. Once you are done pinning, check to make sure your battery fits. Better to make corrections now than after sewing. When it's good, sew around the whole pocket. This particular sewing job doesnt have to look good (mine doesn't), no one will see it.
Both the liner and shell will be sewn right-side in. The liner will be left the way we sew it, the shell will be turned inside out after sewing, so all the seams will be hidden inside the bag.
I then pinned the liner together. You might notice in the pictures I cut the bottom corners of the front and back diagonally, almost to the sewing line. This was to allow the side/bottom piece to remain "flat" around the corners. The front and back seam allowances would then overlap in the corners, presumably giving minor amounts of additional strength. Or not, I don't really know, but it made sense in my head.
Go ahead and sew around both sides of the liner with a straight stitch, and trim your excess thread when done. Now you can complete the liner by trimming the extra fabric around the seam. Be careful, if you cut the stiches open, you'll have to start the liner from scratch.
Finally, the canvas outer shell will be sewn together. This was a bit more complicated, so grab a glass of patience (or liquor) and follow along.
First, we will need to sew a couple seams. One will be on the top of the front piece of canvas (the one with the eyelets), and the other two will be on the outer side/bottom pieces (the one WITHOUT the grommet). These seams will need to be double folded, deep enough to allow the rest of the bag (with seams folded) to stick up above this seam by at least 1/4", but not so deep your grommets or plastic sheet are exposed. This is so the holes on the front and sides (which are intentional), do not get sewn shut when the top seam, liner and zipper are sewn in. I screwed this up, totally forgot to do this step (although it was planned, and on my list of steps), and it was a ROYAL PAIN to work around. So don't be like me, and save yourself some headache by remembering this step.
Now the outer canvas shell can be pinned and sewn together. Remember how we taped some cardboard to the plastic backing? This is where that step comes in handy. Hopefully you left the front side showing. I placed some double sided tape on the plastic piece, and fixed the front canvas (with the eyelets) so the eyelets lined up perfectly with the black dots we made earlier. It's a little difficult to see through the hot glue, but not super hard. Include the controller so everything behaves the way it would when it's all completed.
With the front lined up to the LED locations, you can line the front/plastic/cardboard up with the front interior canvas. I would suggest pinning these two portions together, so they dont move around while working with the rest of the fabric pieces. Try to get the sides and bottom of the front piece pinned to the inside piece as close as you can to the plastic/cardboard spacer. I placed the pins on the sewing line, pointed in the same direction as the line, to get the tightest fit. This will create a skinny pocket which gives adequate room to slide the plastic backing after we attach the LEDs, but will still hold the hot glue diffusers against the LEDs. While pinning, check frequently to make sure everything stays aligned. Once pinned, you can cut the corners like we did with the liner. Leave the plastic/cardboard spacer in until all pinning is complete.
Now the side/bottom canvas pieces can be attached. First, pin the two long pieces evenly together so they stay aligned. Ensure the hems we created earlier on the one side/bottom piece fold in towards the side/bottom piece with the grommet, for a smoother look. Pin this to the front piece so the front of the bag is on the inside, and the hemmed side/bottom piece is on the inside. Both grommet pieces will be on the outside. When the shell is sewn, the bag will be turned inside out, so everything on the inside now will be on the outside after, and vice-versa. Work around, removing one pin at a time from the front, and carefully pinning the two side/bottom pieces, working around in the same fashion as the liner. Cut the corners on the back canvas, and attach that to the side/bottom pieces.
Now you can carefully remove the spacer, and sew around both edges just like you did with the liner. This will be a thicker seam, so you may need to increase your stitch length to avoid problems during sewing. Trim up the extra thread and the extra fabric and flip the whole thing so the right sides are out.
Now, take a break and pat yourself on the back. In two lines of stitches you just made a bag, a pocket, and a long runner to hide wiring. Feels like an accomplishment to me!
After your well deserved break, you better get back to the sewing machine, this is a sweatshop, not a vacation! You're getting close though.
Next, we will attach the zipper, liner and bag together. First, you will want to fold and press the seams on the top of your shell, making sure you have that 1/4" minimum clearance above the rest of the bag. Press the seams rolling them into the bag, folding it at least twice. Now push the liner into the shell and push it against all sides and the bottom, fitting it as well as possible inside. Now you can roll the seam to the outside of the liner, lining it up slightly below the top of the shell seam. You can get away with only one fold for the liner, no need for two. Mark the fold, take the liner out and press that seam.
Place the liner back inside the shell, fitting it well. now tuck the seam of the liner under the shell seam, making sure it is as far up the sides as possible. I pinned it together here.
Now the zipper can be added. First check the zipper is the correct length, and trim if necessary. Once you feel good about the length, you can tuck it in between the shell seam and liner seam, and pin all the layers together. I did one side at a time, leaving the pins in the other side. Be careful the liner stays as far up under the shell seam as possible, so they all get attached together when it is sewn. Once you feel good about it all, you shold be able to sew everything together in one go. the limited space may make it difficult, so don't be discouraged if it takes a few seperate lines of stiches.
The last part will be attaching the D-rings to the side. I just sewed them on with a ton of thread. I wanted to use strap material to make a better connection, but haven't gotten around to that yet (I had an event and wanted to use my bag, so I sacrificed some asthetics. It's dark in events, so no one has called me on my shortcut yet). However you attach them, make sure
For the strap, I used one I found at the thrift store, with clips on the ends. It would look better if I made one myself, but like I said earlier, it's dark. The LEDs also take all attention away from any shortcomings of the bag.
Step 6: Preparing to Solder
Assuming you are using the same LEDs as I am, you can see they have four pads, and no indication what each one is for. They are pretty stripped down, that's why they were so small and inexpensive. For ease of use, the pads should be marked.
Consult the schematic for your LEDs, and figure out which pad does what. Mine have four pads, power (pwr), ground (gnd), data in (din), and data out (dout). I used different color permanent markers, and placed a dot next to each pad. Red for power, black for ground, yellow for data in and blank for data out. I just laid mine upside down, in a line, turned the same direction, and marked each color down the line. The front of the LEDs should have a notch in one corner to help you determine which pin does what.
Do you remember making the reverse image of the LED layout template on the back of the plastic piece? Now is the time it comes in handy. Cover the reverse template in double sided tape, and stick the LEDs pad side up onto the LED locations, taking care to have them turned the same direction. This will ensure correct wire lengths and spacing to solder them together, and hold the LEDs in place.
Now it's time to get your soldering supplies out, we're going to make some electrical connections!
Step 7: Soldering the LEDs
It is best to take a production line approach to this task. With almost 250 connections, there will be lots to do, tackle it one task at a time.
Something to note, power and ground are not directional, so you don't have to follow the same path as the data lines. The order the data connections are wired in determines which number each LED is recognised as by the controller.
First you will need to cut and strip all the wires. Make sure you give a little extra length to play with. I used long pieces of wire for ground and power, short jumpers for data. For power and ground, I stripped a long section off one end, then cut the insulation in small pieces, and slid them down (but not off) the bare end, and bent the small bits of bare wire to make small nubs for the connections. Keep them organized, I stuck them on the tape in their respectful places.
After cutting and stripping, its a good idea to twist the ends of the wires together at their respective connections. All the power and all the ground wires will be long daisy chains, the data wires will stay seperate.
Now the wires can be soldered to the pads. There are a couple approaches to this, probably more I didn't try. I found using both methods to work well.
The first, is to tin the wires and pads separately, hold the wire to the pad and heat just enough to let the solder flow. A little extra solder can be added, to get some flux going in the final connection, just be quick about it.
The other is to hold the wire on the pad, heat the wire with your iron and add some solder. The tip doesn't really need to touch the pad, it absorbs heat from the wire pretty quickly since the wire is so thin.
I used alligator clips to hold my wires onto the pads. I just stuck the clips to the tape, wherever I needed them. With this method, it was best to do the innermost wires first (which were the data wires for me), then the outside wires.
If you are using a different LED, your job will probably be easier. LED strips and pre-made shapes are the quickest and easiest. Consult your schematic to ensure you are making the proper connections.
Don't forget to test with a multimeter as you go along (discussed in the next step)
Step 8: Testing the LEDs
While I was soldering, I just tested continuity. About all you can test is that your power and ground wires aren't broken. Continuity doesn't flow through the LED data connections, so it's not a huge help, but it is something.
After all the LEDs in a group have been connected, run a test with the controller board. I used my UNO and a mini breadboard to make the test circuit. Carefully remove the LEDs from the tape. If possible, use alligator clip test wires to connect the wires to the controller board, so you don't have to solder to the board yet. Connect power to the Vout pad, ground to the GND pad, and data to the D1 pad (or whichever pad you designate for your data out pad).
Connect the USB up to your computer, and open up the Arduino IDE. I ran the strandtest program from the Adafruit Neopixels library, so I didn't need to connect my switch yet. If you don't have that library, it can be downloaded here (https://learn.adafruit.com/adafruit-neopixel-uberguide/arduino-library). Tips on installing can be found through a link on that page as well
If everything works good, then the connections are good, and you can move on, if not, check all the connections and repair the problem. My most common issue was fried LEDs, so I replaced the first one not working, and tested again. I also forgot to change the number of pixels in the code from 60 to 62, so when I tested the whole strand, the last two didn't light up, so make sure you check that as well.
Step 9: Secure LEDs
Flip the plastic backing so the front side is facing up, and get your glue gun ready. Using small dabs of hot glue, secure each LED in it's respective location, light side pointing up, centered in the black dot. They should line up easily, since they were wired up in the final pattern, just flipped over.
Once you glue them all on there, it would be a good idea to slide the whole thing into the bag pocket to check alignment with the eyelets. It will be harder after this to realign any of the LEDs. Include the controller board, so everything is where it should be when completed.
If individual LEDs are off, you can pry them up, scrape the glue off and secure them in the correct position. If the whole board is off, trim the edges so it lines up. It's okay if the board isn't snug, I added velcro to hold it in place.
Once placement was satisfactory, I covered all the exposed leads with hot glue, to prevent shorting out on the eyelets. I also added a lot more glue to secure the wires and hold it all down.
Step 10: Wiring It All Together
First, I took care of the membrane switch. Plug some long, differently colored breadboard wires into the center and left hand connectors (write down or remember which goes to which connection). Slide some heat shrink over the whole thing, and squeeze a hefty glob of hot glue in there. Shrink the tubing over the connections, this will hold those wires in place.
Thread the wires through the path we made in the side/bottom canvas. Once they are all the way through, take them through the side grommet, to the front grommet. I used a really big needle to do this, but you can probably figure something else out. Cut and strip the ends, these will go to the GND and D2 pads. I am going to add a jst connector just before the controller, but I didn't have one, and wanted to complete the project. I will just cut the wires and add the connector when I'm ready to.
The button part of the switch can be secured where the wire was run, or you can do like I did, and attach it to the side with some velcro sticky pads (get the fabric ones or it won't stick)
Next, we can solder the wires to the controller. I stuck the wires in from the top of the board, so they fit better. I used the wiring diagram in this tutorial (https://learn.adafruit.com/animated-neopixel-gemma-glow-fur-scarf/wiring). Here is where the connections go:
Gemma Vout - LED power
Gemma D1 - First LED data input
Gemma GND - LED ground and center membrane switch wire
Gemma D2 - Left membrane switch wire
Last in the wiring is the battery. Here are some warnings, and tips to help you use them safely and effectively.
The Lithium Polymer battery can be very delicate, and very dangerous, so special care needs to be taken. They can catch fire if they get wet, or punctured. They also have fairly weak wire connections to the battery, so we need to beef them up a bit. As small, light, and powerful as LiPo batteries are, there are certainly some advantages to other, safer battery options.
Now, with the precautions out of the way, the battery can be taken care of. First, cut the red wire somewhat close to the battery, strip the ends and splice each end to one of your power button wires. Next, add a dallop of hot glue to the base of the wires at the battery, to strengthen the connection to the battery. It's also wise to rubber band the wires to the battery, to further prevent movement, just don't band it too tight, and DO NOT under any circumstances, zip tie the battery. Let's not light our cool bag on fire, okay?
With all that done, we're nearly ready to rock. On to the code!
Step 11: The Code
It is fairly simple, but there's still a bit to do. If you use the same code as I did, you'll need a few things.
First, read up on the Gemma, the bootloader, and everything else you might need to know about this board
Next, download the Arduino IDE 1.0.5 rev. The latest IDE will generate code too large for the Gemma, and you risk overwriting the bootloader. The bootloader can be recovered, but it takes a little work. Here is an available download of the 1.0.5 IDE, with the Gemma support already built in!
Don't forget to install the drivers if you're using windows
You'll also need the FastLED library. That library can be found at the link below. There is a link on that page to guide you through installing libraries, if you still need that information.
The code we will be using is also on the last link. I did not put the code in this Instructable, because I did not write it. Seems unfair to post something I didn't write.
Connect your board up to your computer via usb. Open your IDE, then copy and paste the code into the IDE. Edit any variables you need or want to. I changed the number of LEDs to 62, and the brightness to 150, which is still super bright, and gives almost double battery life. Press the small button on the board to enter bootloader mode, and load the code onto the Gemma. Everything should be working, and your bag ought to be having it's own little party.
There are some variables you can change in the code. You will need to change the number of LEDs, if your amount differs. You can also edit things like brightness, saturation, speed, and gradient. All the variables are explained on the page containing the code.
If you want, you can use other code, or write your own. Just know, you have about 5.25K of space to work with on t Don't load more than that, or you will overwrite the bootloader.
Step 12: Enjoy!
Just know, side effects include lots of attention from drunks, kids and ravers. Don't say I didn't warn you!
I hope you enjoyed this instructable, it's my first one, so feel free to let me know anything I could do to improve upon for future 'ibles.
I'm entering it in the full spectrum laser contest, so feel free to vote for me, cause I'd love that laser, or 3d printer. Those items would sure allow me to bring my LED creations to a whole new level!