Introduction: Solar Powered RGB LED Magic Pathway
Hey there, thanks for joining me for my second instructable! I always like building things with an extra bit of fun, and had just gotten to experience the magic of neopixels when building my steampunk raspberry pi project. One of the things that really intrigued me was that with three wires...you could power and control a string of RGB lights which were fairly bright, low powered, and easily controllable.
I combined a simple paver pathway with neopixels, some glass blocks, and a 45 watt solar panel system I'd gotten from Harbor Frieght for this project. It doesn't have to be solar powered, but it honestly would be almost a bigger pain to not use solar, as you'd have to run some sort of power to it regardless, and you'd have to convert it to DC.
First and foremost, I'd like to give credit to depot devoid for his excellent instructable: https://www.instructables.com/id/How-to-Make-a-So...
And I'd like to quickly mention: I've entered this into the Solar challenge AND the outdoor challenge...if you think it's worthy, I'd appreciate a vote in either of those categories. I don't do this for the competitions, but I do enjoy that aspect. In the end though, I want you to hopefully learn from what I built, and learn from my mistakes.
That was the source of the idea to use glass blocks, with LEDs under them, as a way to light a path. I started with that concept, changed it to an Arduino with neopixels, added in a bit of a bigger solar panel system, and a motion sensor to conserve battery. This became the basis for this project. Now that you've got the initial idea, I'll start off describing the components and initital planning
Update: 10/12/2017 - I've uploaded an image with a rock border to show it a bit more 'finished'. Also, I uploaded a 3 minute video which shows this end to end...it was filmed in the day so the lights aren't as striking as they are at night, but it shows the animation and triggering of the motion sensor, the motion sensor mounting, the Arduino, charge controller, battery, and solar panel portions, as well as how the power and Arduino are plugged into USB ports in the shed. Hopefully for those that want to build something similar, that helps a bit. Thanks a ton for the support, suggestions, questions, and favorites...I wish you all well that decide to build this, and please feel free to reach out if I can help in any way.
Step 1: Ingredient List
For this project, I chose the following. Please note that these were my choices, and are by no means requirements (I'll list those later for the electronics). Of note..I'm an electronics/software geek first, and my experience installing outdoor structures is novice, at best.
1) 16x16 pavers to run along the sides.
2) Paver base sand
3) String, stakes, levels for laying out the pattern
4) 16x8 pavers, similar in height to the ones mentioned above, for the middle 'row'
5) Sacrete Permasand, or some 'sealant' to put down which will help lock the pavers together
6) Optional: Paver base panels (example: http://www.homedepot.com/p/20-04-in-x-36-in-Black-...). I used those, as I'd never installed a walkway before, and I was in a situation where digging was both difficult, and undesired (I was above some sensitive cables). This allowed me to save 4 inches of digging to place a rock layer. If you don't get this, you'll want 4 inches of gravel to place below your sand layer.
7) 2x4's...you'll temporarily use these to help frame in the sand, and to scree it. I'd say 2 for every 8 feet of the pathway (assuming 2x4x8), plus an extra one to scree the sand with.
For the electronics:
1) An Arduino...the variety shouldn't matter...an Uno would work fine
2) I will go over electronic calculations, but I used 2 USB cables which I ended up cutting the ends off of
3) 14 gauge wire...I used 100' rolls for my setup (Amazon had a six pack for a reasonable price)
4) 22 gauge wire - I used this for the signal wire
5) Lenghts of PVC pipe
6) I used 12 LED neopixel rings, and they've been amazing...plenty bright at night, and with that many LED's it makes things very flexible for controlling power draw. Link: https://www.adafruit.com/product/1643
7) Glass 'blocks' like those used for shower/privacy walls. I searched for glass blocks on my favorite local shopping app (offer up, let go, craigslist, etc) and found quite a few people/ offering them up for just a few dollars each. I purchased 14, and used 8 for this project. The extras are good for prototyping.
8) Rustoelum Frosted glass spray - This stuff was magic when combined with the glass blocks...credit to my wife for suggesting it, it really gives this project a great 'look' and also hides some of the challenges you'll face later when mounting the LED's. Example: http://www.homedepot.com/p/Rust-Oleum-Specialty-11...
9) Conformal coating (link: https://www.amazon.com/MG-Chemicals-Silicone-Modif...). This helps with waterproofing the electronics
10) CorrosionX HD spray - Again for waterproofing and helping avoid corrosion - Link: https://www.amazon.com/Corrosion-X-90104-Heavy-Du...
11) Clear Sillicone caulk and a caulk gun to apply it - This gets applied to protect the electronics, and as an extra layer of water protection.
For the Solar panel system, you need three parts:
1) Solar panels - I used a 45 watt kit from Harbor Freight (They were clearing them out to replace them with 100 watt systems, which might be better suited)
2) Solar Charge controller - Mine came with the panels, but you can get them on Amazon pretty reasonably for under 40 dollars
3) Battery - I'm using a 35 amp hour battery, which provides me about 5 hours of solid 'on' time if I chose. With the motion sensor and limiting times that the panels are on, it gives me plenty of time.
The price for this project varies greatly on the length of the walkway, the type and quality of bricks you choose, machinery and tools you own vs. need, if you already have solar power established (or choose to go another way) etc. The most costly parts of this project were not the electronics, LEDs, etc, but the rest. I estimate it cost me about 15-20 dollars per light when I figure in the wire, waterproofing, led rings, etc.
Step 2: Basics of Making a Paver Based Pathway - Part 1 Prepping and Digging.
Again, to be clear, I'm not an expert on paver pathways. I looked at other instructables, youtube videos, etc. for ideas on how this part is done, and then did the best I could with what I had. That being said, I noticed that a lot of videos started out with 'clear the land', and then showed a clean, prepped area where they could get into laying down sand. So I want to give the steps I took, in hopes that the 'clear the land' part can be broken down a bit more to help people out. This first part is about getting things 'removed' before we actually start building.
- Mark out the space you're planning to put the path in
- Call before you dig....in the US there are numbers you can call (811) to have your land marked for utility lines, electrical lines, phone lines, etc. This is important for safety, and to make sure you don't cut into something you'll regret. I honestly don't know how this works internationally, so please take a moment to research it for your areas to see if a similar service exists.
- Once the markings are done from the utility company, you can compare it to where you planned to dig, and adjust accordingly. After this step, you should have your area marked out and locked in.
- I picked up a few bricks at first...then laid them out in various patterns. I worked in the glass blocks, and just prototyped my pattern on location, so I could check things like width, look, depth, etc. Please see the pictures above for what this looked like...it's basic, but it's worth it. I compare it to picking out paint splotches. Mark your permiter with string line
- The next thing you'll want to do is define the depth that you need to dig. For my approach, I placed the paver base mats down, placed the pavers on top, measured that, added 2 inches for sand, then had my target depth. If you're using Rock vs. Paver base, expect to lay about 4 inches of rock, 2 of sand, plus your paver depth.
- Once you're ready to dig, I recommend investing in a tiller. I picked up an Earthwise Tiller . I spent 2 weekends digging for hours with shovels...that tiller did 5 hours of work in about 15 minutes without any strain. Unless you're looking for a workout, I highly recommend going that route.
- Till the land (or dig the land) along where you want the path to go in, and add in about 4 inches on either side. Till to the depth you defined in step 5
- I had round head shovels..they were terrible for squaring off the sides, so I picked up a flat head shovel. It helped with squaring the holes and keeping the base somewhat flattened.
- Once you have the dirt removed, I recommend 'tamping' the ground to pack it. If you haven't used a Tamper before, they look like this and are incredibly useful for projects like this.
- At this point you should have...a hole. But a clean, sizeable hole with which you're getting ready to start building back up.
Step 3: Basics of Making a Paver Based Pathway - Part 2 Layers
Onions, parfait, ogres, and paver installations all have something in common...layers. The next step is to start building up the layers, again in a prototyping fashion. Here's the steps that worked for me:
- Double check your depth....I laid a 2x4 down on edge to fill in for the sand, then placed my layers on top and ran a level across the top to the grass/ground on the side...if that's level, then your installation will be level with the ground when it goes in. Make sure that's as level as you want it (I actually wanted my pathway slightly above ground, as I was working to smooth a slope, and so I knew I'd be backfilling dirt later to build up around the path and level it. Just an idea of a way to approach leveling, especially on a sloped area.
- Lay down a layer of weedblock or two. Might as well do this now while everything's cleared out, it'll also make working in the dirt pit a bit less messy.
For the next part, I'm having a hard time describing it...please refer to the pictures as you read, and it should make sense. As you go through these parts, please continuously check the level both across your path, and along it.
- Lay 2 of the 2x4's on either side of the pathway, and then lay more along the path. These will act as sand holders, and help make this next part a hundred times easier. I know, because I lost two weekends of work trying to do it many other ways. :) This is a great time to make absolutely SURE you're level...you're about to pour sand, and not being level here can wreck things. If you're designing it to lightly slope (I had to do part of my path that way) then this is where you can check the slope consistency.
- When you have the sides lined by 2x4's, then pour your sand in, going higher in the middle. Pour bag after bag, with the goal of going to the height of the 2x4's or a bit higher.
- When you have a bit of sand poured, then take another 2x4, and cut it to just over the width of the ones you've laid on the sides. This should extend probably about 6 to 8 inches past on the side
- "Screed" your sand...this means place the 2x4 across the others, use them as rails, and pull the board towards you. Here's a video portion that will help demonstrate it. Note: this is often done with PVC pipes on the sides, which I attempted. I found the 2x4's to be much more stable with a lot of auxiliary benefits for how it stabilized and held my sand.
- Keep working your way down till you have a nice level sand surface, which is now on top of your weed block
- Next layer is the paverbase. For mine, this laid upon the sand, and overlapped in the middle and ends
- Finally, you can lay your pavers on the paverbase, and place your glass blocks on top of the paver base
- Note: The glass blocks are likely MUCH thicker than your pavers...that's ok, there's a trick to fix this...we'll actually cut out the paver base, dig out the sand, and then place the glass blocks into the remaining holes so that they lay flush. To cut the paver base, a carpet knife, razer blade, or even sharp scissors should suffice
At this point, you should be able to lay out your path, walk on the pavers, and things should feel solid for the most part. Any looseness here should get locked in at the end...but next up we have the electronics!
Step 4: Step 4: Electronics Planning, Considerations, and Power Consumption Calculations
The next parts the fun part. I made up this approach, and it's my first attempt at it. I can say from my finished product it does look good, but that doesn't mean it can't be improved upon, so please keep that in the back of your mind when reading through this. This is, after all, the differentiator between what we're building and most other paths...
- The electronics need to be able to handle the elements...waterproof, corrosion resistant, protected, etc.
- There should be a way to upgrade or replace the microcontroller without having to dig up the entire pathway
- We're running a fair bit of amperate...the design should be such that we can safely get it to the lights.
- Since I hooked it into solar, and my solar controller was able to easily get me 2.4amps of DC at 5 volts (basically lighter->USB adapters like this), I knew I had to do multiple power runs to supply power to my setup.
Let's take a step back for a second and talk about power for this project. I used 8 blocks, and each block had 12 neopixel LED's. To calculate power draw, I had to work through the following:
1) Each Neopixel uses 20ma per color at full brightness (0-255 levels)...and can display up to 3 colors at once. This means a max of 60ma per pixel.
2) Each 'block' had 12 pixels under it...times 60ma = 720milliamps to get a single block to turn 'white' at its brightest setting.
3) 720ma * 8 blocks = 5.7 amps to light everything, but then there's a draw on the Arduino.
Wow...5.7 amps is ALOT...but that's very much worst case. I knew that I was going to use a lighter adapter off of my solar controller, and that the Arduino would draw nominal power (under 20mah) so I wasn't as worried about it. Ok, for my setup, I was using the USB adapter with 2 2.4amp ports for a total possible 4.8 amps. That was nowhere near the 5.7 total, so I figured I'd add some limitations to get a better idea of what was possible:
If I only used 2 LEDs worth of color, that cuts each LED down to 40ma (Essentially don't every try to turn them ALL bright white). This cuts the overall power all the way down to 3.8 amps.
If I DO want all white, then instead of turning on all 12 LEDs, I could limit it to 10 of them...the math then looks like:
60 * 10 = 600 per block * 8 blocks = 4.8 amps (perfect!)
You can learn more at the Neopixel Uberguide . This page from Adafruit is great for strategies of how to optimize the number of pixels you use. I did tests with just 6 neopixels per block and they were plenty bright still, so you really have a lot of flexability here.
In the end, if you, for some reason, do need a ton of pixels...an option is to use an inverter, then just plug in an appropriate power supply. Adafruit makes a 10amp 5V supply that would really get you quite a bit of power. Please keep in mind however...when powering off of a solar panel/battery system....efficiency is pretty important to maximize battery time.
Speaking of...pulling 5 amps off of a 35ah battery gets us a max of say 7 hours...if we use the 'don't drain past 50% rule' to protect the battery that cuts us down to 3.5 hours...so the other design consideration for this project is to have LED's that turn on when motion is detected. Please keep your battery or power source in mind for your design (Maybe a three hour timer when the sun goes down would work for your desires vs. motion)
The video for this section shows me wiring up and testing my power calculations. If you're not sure, then this is really the best way/time to figure it out...just wire things up temporarily, test it, and make sure your grounding, wiring, and such is sound.
Now that we've planned this out and understand power consumption, we can start to put things together
Step 5: Step 5: Wiring Up the Electronics, and Waterproofing
Ok, enough planning, time to get things wired up. Please view the video to start, it'll give you a solid idea of what we're about to achieve. :)
- First thing you'll want to do is solder wires to the 4 solder points on the neopixel ring. I used a black wire on the ground connection, and a red wire on the VCC/Positive connection. Being consistent here will pay off huge, as part of this project requires that the entire ring gets covered in silicone that you won't be able to see through, so wire colors are the only ways to identify what is going to what.
- The other two wires besides power are signal in, and signal out. You should use two different wire colors here, or apply tape to one of them...again pretend you can't read the board (cause you wont be able to soon) and so make sure that things are differentiated. Tip: Make sure that the lengths of wire for the in/out are long enough to go between the glass blocks, plus some. I did a short wire on one side, and longer on the other as I got to the end of this project...the wires were about 24" in length to go from one block to another.
- Before we apply the lights to the block, we need to waterproof them. This is where the conformal coating and corrosionXHD come in...I used a paper plate as a 'backer' for the sprays
- First apply the Conformal coating...this is just brushed onto the electronics...I covered every part of it, the board, a bit of the wire, and then went over everything that was conductive twice. Please see the pictures for exactly what I used
- Next, place the electronics on a paper plate, and then use the CorrosionXHD spray...this is another coating that will both waterproof, and help prevent corrosion. Note: It's a bit of a sickly brown, and it'll make the white of the neopixels a bit of a brownish color...don't worry it wont affect the light they emit. Make sure to spray both sides.
- Place the LED's against the glass so that the neopixels face 'into' the glass block. Make sure that the black/red wires come off to one side, and that the 'in/out' wires come out of opposite ends of the block.
- Tape the wires down with electrical tape. Don't worry, this is just to hold things still while you're placing/wiring things. You should probably wire up the neopixels to test them at this point and make sure things work out.
- Place a generous amount of silicone all over the ring....place enough to both hold it onto the block (once it's dry), as well as try to further protect it from the elements...I tried to make mine airtight, filled in any gaps and crevices, and gave a layer of soft protection to the electronics. Remember this block will be laying in sand essentially, and anyone that steps on it...this layer is part of what keeps the electronics from being crushed. So go crazy with it. (Note: "clear" silicone will look white for a day or so when you first apply it, especially with this much coverage
Further viewing: If you want to know more about waterproofing, the video I watched to learn this was the excellent Flite Test video which shows these techniques used on drones, and discusses waterproofing other components such as servos and such. I have it embedded in the gallery.
Step 6: Step 6: Place the Blocks Onto the Path, and Wiring Things Up From There
There are three things you need to know about this part:
1) There are going to be two wires run from your power source (the solar panel in my case) and then up and down the entire path. These are essentially a power rail...you'll need a positive line and a ground/negative line.
2) You'll have a third wire running from brick to brick...this will form one line for the neopixels signal wire, and will travel back to the Arduino (which will have to be powered, so likely will be back with the rest of the wiring)
3) Remember that discussion about power...for mine I needed TWO power rails (2.4 amps each), so I ran 4 power wires. Keep that in mind, as this is the time it matters..if you're running 4 wires, you'll probably want to run them into the center of the path, and then have the split off. This is how I did mine, and it worked great.
Ok, with those considerations, here's how this goes together:
- I'd clear your center bricks out of your path if you're able, so you can run everything cleanly, test, and then place them. See the first pic above.
- Next pic is showing my path from the shed to the pathway...I ran this in PVC/conduit to protect it, and to allow for burying the wire. Note: This is really the only 'buried' wire in this project...the rest actually will lay along the paverbase, which helps immensely with keeping things dry.
- Place your first block, with the wires, into the ground. Be careful not to smear the silicone too much, and make sure things are level. Dig sand out if needed. Note which side the power wires are coming out of, and make sure you note your in/out wires...your 'out' wires should be facing towards the 'in' on the next block.
- Once you have wires run from your powersource, run them up and down the paverbase along your pathway. Make sure you go a few feet past on either side. I used red and black in one direction, and purple/yellow in another (no particular reason, just ran out of red/black). Again consistency is important! Make sure these power wires run along the side that the power wires from the first block are on.
- Run another wire along the power wires...this is your signal wire. This should go along the power wires till it gets to the paverbase section, then it should peel off and head towards the first block and connect to it's 'in' wire.
- To connect the power wires, cut into the long length where the wires are close. Then strip the two ends from your cut, and the power wire from the block...and connect them all with one of the waterproof wire nuts. Repeat for the other polarity.
- Connect the in/out wires as you place other blocks, again using the wire nuts.
- Connect the ends of the wires near your power source to the ends of a USB cable. Easy way to do this..find a sacrificial USB cable, cut the end off, and match up the red and black wires with the power ones you just ran. Connect them with the waterproof wire nuts, then plug into a USB source such as a phone battery bank charger. Run the signal wire to an Arduino, and program it with the neopixels 'strand test' library. (Note: if things just stopped making sense, then you'll want to learn about neopixels, Arduino programing, and such. Good news, Adafruit has a tremendous tutorial for that here)
- If you're splitting power like I did, then you MUST connect the grounds between them together. I can not stress this enough...the weirdness you'll see if you don't do this can cost you hours of debugging.
- Also, connect the ground to the Arduino to the ground of the power wires to keep a common ground. Again, if you don't do this, you'll get erratic behavior that will make no sense at all.
Continue to place blocks, connect wires with the wire ties, and then optionally (but recommended) electrical tape things together on top of the wire ties. You're going to bury this work under pavers, so you want to test, test, test, and make sure it's built to last.
Ok, if you're at this point, you should connect your signal wire to the Arduino, and run a strand test. The blocks should light up...if not, double check the wiring, common grounds (See steps 9 and 10), and connections/wire nuts. Once you've got all of the blocks working, it's time to clean things up and lock them in place. Please note that you don't need solar at this point...battery banks will suffice.
Step 7: Cleaning Up, Locking in the Blocks, Spraying the Glass
Place down your bricks once you have the lights going, and get everything leveled off. In my case, my center bricks were slightly thinner, so I had to add a layer of sand under every single one of them along the middle row. This worked out good, as it helped protect the electronics a bit by making sure the bricks didn't sit right on the wires. (The first pic above shows this) In addition, if you have any wire nuts that you couldn't tuck underneath the paverbase...you should cut into the paverbase small holes and place them in there. The middle channel of the paverbase acts as a great place to run the wire and clean things up.
Next up: It should look something like picture number 2...almost ready to go, except there should be gaps between the bricks. These gaps are necessary, as we'll dump the paver 'glue' into them. For this next part, dump the paver set (polymeric sand) into the slots...typically this will pile up a bit on the sides, and you'll want to use a broom to get it into the cracks. You'll want to fill all of the cracks, as this stuff will glue things together. It's helpful to hit the pavers lightly with a 2x4 as you do this to get any existing 'stuck' sand to settle. I used my hands to also help get it into areas...TIP: Wear gloves! This stuff reacts to water, so if you get it on your hands and try to wash it off, it just gets stickier. I had to use a putty knife to get it off of my skin (a good tip if you don't listen to the gloves tip).
Once the sand is in between all of the cracks and they're full, it's important to sweep off any excess. This sand can stain your pavers if you don't do this. After that you're ready to 'set' it...simply get it wet using a garden hose with a gentle spray. I used a water bucket, as my hose was broken at the time, and that seems to have worked as well. The last picture is what it looked like with everything filled in and freshly wet down.
Finally, you'll want to spray frosted glass spray on all of the glass blocks...this will help diffuse them, and gives them a much better look than when they're not diffused. It really makes a huge difference on the look, and makes the block glow vs. just light up sporadically.
Next we move to the solar portion!
Step 8: Step 8: the Solar Portion
There are tons of tutorials on solar...and I'm not really qualified to compete with those. I'll give you my short version.
There are three things you need:
- Solar panels - These should face the sun and gather the light/power
- Solar charge controller - This takes the power from the panels, and routes it to the batteries to charge them. If they're full, then it trickle charges them to keep them healthy and topped off without overcharging them (which would be dangerous).
- Battery - This is your storage. Both this and the panels connect to the solar charge controller
- Load - This is pulled off of the solar charge controller, and is how you pull power from the system. In my case, the harbor freight system had 12V lighter ports built in, so I didn't have to adapt anything. I could just plug in a 3 way splitter, and then pull power from a 12v lighter port -> USB adapter that had 2.4 amps ports on it. By plugging both USB cables into those, I had plenty of power for the system. A third USB port provided on the charge controller powers the Arduino.
There are two things you MAY need/want that could help:
- A power inverter would convert DC to AC, allowing you to plug in a wall wart style 10 amp power supply if you have a bigger system. Technically you're going from DC to AC to DC though, which isn't efficient and a loss of power. There are probably ways to go from 12V DC to 5VDC and pull more amps...I'm just at my basic electronic limits of how to do that, and don't want to recommend something that may be unsafe.
- I have a power meter (like this ) This is what you see in the pics above..and it allows me to quickly see the load on my solar panel/battery system at any given time. This is great when running the neopixels to see how much power draw I'm actually using..which is much lower than my calculations for max current draws.
Some details about my setup (Yours should scale to your needs)
- 35amp hour battery - This will run my setup for probably 5 hours or so continuously. I will expand it to 200 amp hours soon to run some other projects, and in case I want to run these all evening
- 45 watt solar panel setup - This would need to be upgraded as well, but for this system it's working great. I only use it on weekends, and so it has all week to charge my batteries.
- Harbor Freight solar charge controller - this is the gray box shown with two white wires coming out of the front in the pics above. Those white wires provide my shed with light, and the cigarette lighter goes to a triple outlet splitter. That splitter has two USB ports on it as well, giving me plenty of options to draw what I need to power the lights, and the Arduino.
At this point you could be complete. I'll add pages for addons like light sensors, motion sensors, and other things. For now, if you have any questions about this, please let me know. i'll work to get video added so you can see some of the effects. Also I will update as I come up with better light 'patterns' as I go along. If you're trying this and hit any snags, or need any part of this clarified please let me know in the comments below! I hope you enjoyed this instructable...till next time....
Step 9: Addendum 1: Motion Sensor
My first addendum is adding the motion sensor...this is mounted and wired in, but I'm still working through some bugs in the code. For now, here's what the mount looks like, and the idea behind it...
- The first pic above shows it mounted to the shed...the second pic shows that it's discreet...it's mounted up high so it can see motion coming from either direction.
- The motion Sensor has a wire in the shed that runs all the way back to the Arduino, which is mounted at the front by the power source.
Up next: I need to add code. The logic is essentially 'upon movement, play an animation to greet the user, then play the rainbow cycle three times, then shut off'. The rainbow cycle takes a minute or so anyway, so this gives them time to pass, then shuts down after a couple of minutes to preserve battery.
Step 10: Addendum 2: Repair and Troubleshooting
Last weekend while walking across this, a potential nightmare scenario happened...I'd sealed in all the pavers, locked in my design, and then...something broke. Three lights turned on, and that was it. After my initial panic, I decided to work out how to troubleshoot the walkway, and how to repair it. Turns out..it's not too bad to fix!
First thing I had to do was figure out what the heck went wrong....here's some tips for that portion:
- Always check connections on the outside first...verify that there is power to the charge controller, that anything such as splitters are plugged in fully and getting power, and then check wiring connections
- The behavior is VERY telltale on what may be going on
- If no lights turn on at all, then it could be that the signal wire isn't getting a signal to them or they're not getting power. Make sure the Arduino is on, the wires are connected, and then check your power lines
- If you ran extra wire off the ends of the path, you can dig under a bit to expose your two power wires, and check for current
- Worst case, see the repair section below to remove a brick. Remove the first one so you can see if you're getting power even to the neopixels..if so, then it's likely your signal wire. Also try shorting the signal wire from the first light to the second..if the first goes out, it may stop the rest
Repair - Good news...it's not THAT bad!
I had not made a pathway before, so I had no idea how to fix them. Turns out, it's not too terrible...if you leave decent spacing between pavers, you simply have to crack the 'grout' and then lift the brick out. To do this, I used a flathead screwdriver and a hammer, and slowly worked around the brick I wanted to remove. Once I had made it around the entire thing, I used the screwdriver as a lever to slowly lift the brick.
Once you get the brick out, you can scrap the excess paver compound/grout off of the brick and the hole you removed it from to clean things up. It may be a bit finicky, but it'll come off. Once that's done, you can look at the wiring...check your connections...see if the wires in the wire nuts came loose, if something broke on your solder joints, etc.
For mine, wires came untwisted in one of the wire nuts where I didn't have enough wire slack. I ended up twisting the wires with pliers, then soldered them together, and added a fresh wire nut. Once that was all done, I simply tested it, ensured everything was fixed, reburied it, and added the brick back. Next weekend I'll bring more paver compound out to reseal it, and be back in business!
I was honestly surprised at how easy it was to cut the brick out using this method. Despite a paver path feeling really permanent, it really seems if you have a chisel or something to cut a brick out, it's not too bad to work your way into it for repairs. Whew!