Introduction: Apple Neon Sign
Disclaimer: I don't own the rights to the logo, didn't create the original logo, and all rights are held by Apple... or something. I don't know the legal aspect but I think that covers it. I don’t provide any warranty to anything, the onus is on you to not screw up, double check the information provided, and check your own work!
Thanks and recognition: I would like to recognize the hard work that Adafruit library team and the IR Remote library team put into their work. If you don’t know how much work it is just open one of the library files and scroll through. Seriously, the dedication and hard work it took to make these so that hobbyists and enthusiasts could have an easier time is really appreciated. Adding to that Adafruit also has some good guides on a lot of different projects and basic skills.
Foreword: This guide is meant for a person who is already somewhat familiar with electrical connections, 3D printing, soldering, Arduino, programming, and a few other skills. This guide isn’t meant to make you proficient at all these things, but if you have these skills already this guide will merely serve as instructions. If you lack these skills consider this an opportunity to learn and develop. I recommend seeking out other sources to learn these skills, as my guide is very high level. Please read the entire guide before buying materials and starting work!
It would be extremely helpful to read the Adafruit neopixel uber guide and connect your LED strip up before you butcher it for this project. This will make sure your strip works, you’re familiar with the connections and the concepts, and that you can upload some code and see how the Arduino works.
Step 1: Preperation
If I were to do this section it would probably take up 90% of the guide. Obviously, it was modeled directly after the 1980's Apple logo. If you're comfortable with 3D modeling software then take a crack at making your own. I may do a tutorial on how to make these at another time, but for now the main focus of this guide is the assembly of the 80's Apple logo sign.
II) Bill of Materials
The bill of materials not only acts as a guide of what you need and where to get it, it also acts a guide during assembly. The item numbers help identify what goes where to help reduce confusion, and gives a quantity of items that are needed. For instance, the backers (item 2, 4, 6, 8, 10, 12, 14) get 2-part epoxy (item 23) applied to the back and are placed on the Acrylic backer (item 22). So, it is suggested that you download the BOM and have it with you as a guide while assembling the sign.
Go to the link in the BOM, or here and get the stl files to print the diffusers, calibration piece and backers. The backers (item 2, 4, 6, 8, 10, 12, 14) are printed with black PLA. You can use any color for the backers, but the black adds depth to the lighting and doesn't distract from the lighting.
The diffusers (items 1, 3, 5, 7, 9, 11, 13) and calibration piece (item 15) are printed with natural (clear) PLA. Obviously, this won't work with anything other than a clear/opaque medium.
A note on brand of filament: I am a huge 3D solutech fan. They have great quality filament for a great price. However, in this case their natural PLA is too good of quality, and it may let too much light through. Instead I use a garbage and overpriced natural PLA from a company called inland. I’ve had the filament from this company backlash so many times, and the quality just looks third rate. Looking at their natural PLA versus 3D solutech you can see a clear (haha) difference. For this purpose, the inland natural PLA is better because it’s crappier. Does that make sense?
Anyway, for the printing process I used Simplify3D with the following settings: nozzle diameter .4mm, extrusion multiplier 1, extrusion width: Auto (.48mm), layer height: .3mm, 100% infill with rectilinear pattern, outline overlap 40%, infill extrusion width: 100%. With these settings print the calibration block to see if your diffusers came out alright. If you can see individual LEDs (with the strip flat on the desk), or if you have pin holes try adjusting some of your settings and print again. This can be the most frustrating part, but with the calibration work I have already done it should be a breeze and only minor adjustments should be needed.
In addition to the sign parts you may want to print an Arduino case (item 31) which makes it easier to attach to the Acrylic backer (item 22).
Print the backers first. You can do some prep work while the diffusers are printing.
IV) Cutting the LED Strips
For each of the backers (item 2, 4, 6, 8, 10, 12, 14) place the continuous LED strip (item 17) in a backer section to measure out where to cut the LED strip. Cut the strip to where it takes up the majority of the backer, but you might want to leave a little space between the end of the LED strip and the backer. If no room is left it will be difficult to rout the cable through the bottom of the backers. Do this for each backer section and keep the individual LED strips separate or label them so you remember in which backer they go into.
You may also want to orient them in the right direction. What does this mean? See the little arrows on the strips? You want to make sure they point in the direction of data flow. I oriented my sign so that the data flows from the top of the leaf backer to the bottom going to the left of the green slice diffuser, which goes from the right of the green slice diffuser to the right of the yellow slice diffuser and so on. See the picture I made to help visualize the data flow. Make sure your arrow directions match mine. If you want to do it in a different way that’s fine, but you still have to follow this “data flow” convention otherwise your sign will not work!
V) Cutting the Wire
For each of the LED strips that were previously cut you will need two power wires, two ground wires, and two data wires from the hookup wire spools (item 19). I would recommend using different colors for the 5V, data, and ground wires. I used red (5V), green (data), and black(ground). You should try to cut the wire sections to about 3 inches long. If it’s a little too long, no big deal you can just tape it down, however if it’s too short you will have to either resolder or splice it. In addition to cutting the wires, now would be a good time to strip the ends to solder and connect them later. One end should be trimmed only slightly, about 1/8 to 1/4 of an inch. On the other end take a bit more off from 1/2 inch to 3/4 of an inch. The dimensions are not strict, and you may find that you want to take a little more or less depending on your preference. Trim two sets of longer than your usual wire cuts to connect the leaf section to the top of the apple.
If you decided to get the USB A-to-B connection (item 30) now would be a good time to carefully cut the wire and trim back the shielding. You can cut down the green and white wires, but leave the red and black wires uncut. Trim back the insulation so that about ½ inch of bare wire is exposed. You will use this to tie into the main 5V and ground line to make for easier connecting/disconnecting of the Arduino (item 18).
Now we can take the wires that were cut and stripped in the previous step and solder them to the LED strips. First make sure that you follow the same wiring color convention from strip to strip. This is important when wiring it later so that we don’t make a mistake. Second, take the appropriate color wire for the appropriate pad and solder the wire to the pad. Use the less trimmed end of the wire to solder to the pad leaving the more trimmed end free to connect to the next LED strip’s wires. Solder each end of the LED strip except for the last strip, which will only get wires soldered where it will connect to the previous strip. You may also want to solder the 470 Ohm resistor (item 20) to a small section of hookup wire (item 19) on one end and a cut and trimmed male Dupont wire (item 29) on the other. If you don’t use the Dupont wire you will have to solder the resistor or hookup wire directly to the appropriate Arduino lead.
With the 1000 uF capacitor (item 21) solder two sets of red wire to the longer (unmarked side) terminal, and solder two sets of black wire to the shorter (white, 0 marked) terminal. Go ahead and insulate each terminal and connection separately with electrical tape (item 24).
If you elected to get the USB A-to-B connection (item 30) you may want to solder it at this point to the main 5V line coming from the power supply, and the ground as well.
If you elected to get the IR receiver (item 26) then go ahead and solder some cut and trimmed male Dupont wires (item 29) to the IR receiver leads. If you’re looking at the IR receiver from the front then the order goes 5V (red wire, right lead), ground (black wire, middle lead), data pin (green wire, left lead). Tape up each lead when done soldering to prevent them from coming in contact with other wires or leads.
Step 2: Assembly
Set the backers (item 2, 4, 6, 8, 10, 12, 14) on the Acrylic backer (item 22) and align the backers in the general shape of the sign. The black backers are meant to butt up and be in contact with each other. Mark the areas of the cut outs with a silver sharpie. This will help with the layout when you’re putting glue/epoxy on the backers.
Optional: At this point you can remove the backers and drill holes inside where you marked the openings in the backers. This is really nice if you want a clean looking presentation of the front of the sign. This part is optional, but if you want a really clean aesthetic you might want to do this. First drill a smaller pilot hole in the middle of each marking. Then drill a larger hole into the pilot holes you drilled. WARNING! Go nice and slow when drilling the holes. You can let the drill go full speed but do not put much if any pressure while drilling. You can see what this can cause, and lucky for me it only made a chipped hole. If you’re unlucky it could crack the entire section of the sign! Slow and steady and you’ll get good holes for your cable management.
Whether you decided to drill the holes or not now it’s time to apply the 2-part epoxy (item 23) to the backers (item 2, 4, 6, 8, 10, 12, 14). You may want to have some clean up stuff handy (plastic bag, some paper towels) just in case. You can either mix the 2-part epoxy in a throw away container and then apply the mix to the backer, or you can squirt the 2-part epoxy directly to the back of the backer and mix it on the backer. Either way, don’t put too much on the backer as you don’t want it to gush out the sides of the backer. If it does it’s not a big deal, you probably won’t see it unless you look real close. The epoxy says “5-minute set” but don’t worry too much about that, you’ll have time to mix and apply, but I wouldn’t recommend mixing a big batch to do the whole sign at once. Just mix in small batches or on individual backers and you shouldn’t have a problem. Now place the backer down in it’s appropriate location and apply just a little bit of pressure to make sure the backer and the Acrylic backer make adequate contact.
Use the guide markings to help you put it down in the position you had it in earlier. After you got the backer down you can make some minor adjustments to its position. The backers may move very slightly as the epoxy cures, but it will be unnoticeable from the overall assembly of the sign. Don’t worry, you don’t have to sit there and baby sit it! You’re done with the backer assembly! Let the epoxy cure for at least 6 hours before messing with it again. While you’re waiting for it to cure you could do all the stuff from the preparation section 4, 5, and 6.
II) LED Strips Installation
Now that our epoxy has cured and you have done some prep work we’re ready for the LED strip installation. Remember the orientation part of your strips that you made sure was right during the strip set up? Yep, we need to remember to install our strips in that same orientation, or else! Before putting down any of the LED strips remove the “3M” adhesive protective strip. I used “3M” in quotes because it’s laughable to equate this garbage adhesive with 3M. I still think it stands for 3 Minutes because that’s how long it’s going to last. We will tack these down later with super glue, but for now just remove the adhesive protective strip. If you drilled holes in your sign for cable routing carefully thread your wires through the holes and try not to bend the LED strips too much and be careful with putting excessive tension or bending on the wires at the solder joints. If you break a connection here you may have to cut a new strip and resolder it. While I didn’t do that with the LED strip that I ordered (the CHINLY 5M strip) I have had crappier strips do that especially with the data line. The CHINLY brand seems to be a little bit more reinforced when it comes to their copper pads.
With each strip having the adhesive protective strip removed, in their correct orientation, and in their appropriate backer, begin twisting the wires together as you place each strip in. This way it’s harder to screw up and you don’t have a million wires poking through the back with you wondering “what goes where again.” While you’re at it you might as well wrap the connection in electrical tape (item 24) now rather than wait until later. If you have the Dupont wire (item 29) and alligator clips (item 28) to easily wire the sign up do a quick check just to make sure everything is working before moving on!
Now that you have tested your sign and everything is working properly start tacking down the LED strips using super glue (item 25). The “3M” “adhesive” won’t hold the strips down on its own, so the super glue isn’t optional. After applying a strip of super glue below the strip press the strip down gently and hold it there for a few seconds. It doesn’t matter if the super glue oozes out here because nobody will ever see it except you. It’ll be our little secret! After you have the strips tacked down successfully with super glue test the strip again just to make sure nothing came loose.
If everything is still looking good do a little bit of cable management. If you drilled the holes in your Acrylic backer then tape down the cables first where they come out of the holes and then tape down the middle section. Also secure any loose section of wires like the capacitor section and the If you didn’t drill holes you can tape down the cables where they exit the backers first and then decide what to do with the remaining cable. If you have a black Acrylic backer and black electrical tape you can try to hide the cables by completely taping over them. This will probably be unnoticeable from a distance. Give it one last quick check before moving on.
One quick note: to test the strips as you go not only will you need to hook up the strips properly, but you will also need to load some software onto the Arduino (item 18) before it will work properly. I would recommend visiting Adafruit to learn the basics of wiring, and to get the Adafruit neopixle library and example code. You should hook up a strip according to the guide and upload the code to the Arduino to get a feel for what you’re doing and to test everything.
Let’s go ahead and wire everything up to the Arduino (item 18). If you’re just temporarily hooking up the Arduino to test you will need to share a common ground between the Arduino and the LED strips. Connect the 470 Ohm resistor (item 20) that we soldered together earlier to the digital IO port 4 (you can specify whatever port you want in the software, and if you’re using the strandtest.ino then use port 6) on the Arduino. If you have it connected right and you upload your code your sign should come to life. If not then don’t get frustrated, do some simple troubleshooting. I would suggest testing the wiring on the strip before cutting it up, or you can cut out the section with the bulky connector at the beginning and use that to test your connections and code.
If you elected to get the IR receiver (item 26) then go ahead and hook it up now. The red wire should go in a 5V port on the Arduino, the black wire should go to ground on the Arduino, and the green wire should go to digital IO port 2 on the Arduino. You don’t need this part to make the sign work, it will just give you more control over the project.
Don’t forget to put the diffusers (items 1, 3, 5, 7, 9, 11, 13) into their respective backers before continuing.
Step 3: Code
Now that we got the sign fully assembled let’s upload our code instead of using the strand test provided by the Adafruit library. Open the Apple_Sign_Alpha.ino in the Arduino development environment. Upload that to your Arduino that you’re using to control the sign. You will notice there are a few comments in the code to help you customize it easily to fit what you want to do with it.
Since I’m not a CS major nor a very good programmer customizing different functions is going to be up to you! I took out a lot of functions that I am currently working on because I didn’t want to add to the clutter of the code… and I didn’t want anyone to see my bad programming skills. Let your imagination run wild here! This is where you can make the sign your own, and do really cool custom functions and animations. Want to make it look like there’s a bad section of the sign? You can program that! Want the colors to shift to each section of the apple? You can program that! Be artistic with math n’ programming ‘n stuff.
Step 4: Finishing Touches
So, now that you got your sign working the way you want it and everything is looking good it’s time for the finishing touches. If you printed out the Arduino case (item 31) then place the Arduino inside it and take note of where your digital IO ports are for the strip and the IR receiver (if used) when putting the cover on so you can put the correct pins in the correct ports. Now that you have the Arduino in the case, put a piece of Velcro tape (item 32) on the back of the Arduino case and the other part of the Velcro tape on the Acrylic backer (item 22). Route the IR receiver (item 26) wires and tape them down. Put the IR receiver somewhere it is unobstructed and can get line of sight with a remote. Last, look for a big open spot (hopefully you left one) so you can put some of the Velcro tape (item 32) onto the 5V power supply (item 16) and slap that to the back of the Acrylic backer (item 22) as well. If you want to you can super glue (item 25) the diffusers (items 1, 3, 5, 7, 9, 11, 13) to the black backers (item 2, 4, 6, 8, 10, 12, 14) to keep them in place a little easier. I wouldn’t recommend doing this until you have your sign working the way you want it and tested everything. There you have it! A nice, presentable sign.