Sorry in advance if this post is inappropriate for this forum, but I imagine many users will be thankful to have come across it, because digitally addressable LED strips are not cheap to come by on the internet. Please let me know if it is and I'll take it down.
I bought 250 meters of LED strips from China a few months ago for a big project I was working on. The project ended up changing course, and now I have over two football field lengths of LED strips sitting in my small NY apartment.
I'd really love to get rid of them, and am willing to part with them around the price that I paid for them. There are 50 x 5 meter reels. Price: $80 per reel. Free shipping.
See the specs below. If interested, reply or message me. I can provide more photos and videos of them in action. Thanks!
These work exactly like the LPD8806 strips seen on adafruit and elsewhere online. I have had zero issues with using them with the LPD8806 arduino libraries that are floating around out there. They're nice and bright, like I would have expected. I think I only ended up opening like 2 of the packages to test with, so 90%+ of them are still fresh in their packaging.
Do we get an extra reel by posting a review? LOL! j/k Ryan!
I did not pay (much) attention to the actual specs on the strips. They're not coated! Nor do they have a sleeve (this was mentioned in the original post, I just read right over it.) So they are what I would call 'bare' strips. This is important if you plan on using these outdoors or without any kind of enclosure. Other than that, they're 48 pixels per meter (which worked out perfect for my R&D process). Detaching them at the solder joints is a tad tricky. You can cut where indicated, but if you want to cut an actual solder joint, you're not left with a whole lot to solder onto afterwards, so I always detach the joints themselves. This one is a bit tricky because the solder pads are tiny circles and they stack them on top of each other at the ends. So the best way I could do that was to insert a thin set of fine tipped straight tweezers in between the layers right around the solder joint and as I heated it up, gently push the tweezers in and separate the layers. This leaves both the top and bottom pads intact and ready to have wires soldered back on them. Some strips have larger pads and they're soldered side-by-side making it easier to simply cut the joint. This one has the edges on top of each other. But once separated, it's easy to get wires back on. Another thing to keep in mind, especially for those who have dealt with WS28x strips before, VCC and GND are next to each other on these. The WS2801 strips I have are different in that VCC and GND are on the outside with CLK and DATA in the middle. I actually prefer that as there's a much smaller chance of accidentally creating a solder bridge between VCC and GND. On the plus side, it has two GND pads which makes for a stronger, more secure connection. I wish they did the same for the VCC pad but alas. That's it, strips work beautifully.
So my reason for getting one was two fold. On the one hand, I wanted to make sure I wasn't doing something wrong versus the WS2801 strips I have being just too slow for what I am wanting to do. On the other hand, I just wanted another IC to play with. I've always only worked with the WS28xx series ICs and strips so why not. I already had a sneaking suspicion that it was the WS2801 strip (note, 2801, not 2812, although their speed is the same) but I needed to make sure. And rather than waiting 2 weeks for my vendors in Shenzhen to send a test reel to me, Ryan, you were a savior here.
So, I'm working on a custom, full color POV system, like a poi baton. Most, if not all of the stuff I see have static patterns and are limited in color, mainly because everyone stores it in memory of which there isn't a whole lot to begin with. So my system stores images on a uSD card. The program then reads each individual column of the image and pushes the data out to the string, constantly. At 48 pixels tall, I just need three bytes, r, g, and b. So I read in a total of 144 bytes (48 pixels) each time and push it to the string, then read the next 144 bytes, etc., etc. The only delay is with the uSD itself. On average, it takes 108 usecs to read 144 bytes (out of cache) and about 1250usecs every 4th read to refill the cache. Plenty of time to goof around with.
Turns out, I was right, the WS2801 is simply too damn slow. Here's what the WS2801 strip would do when I tried to push data to it at full blast:
And this is what it's supposed to look like. This is running on the LPD8806 IC:
Now, I could've just as easily slowed the process down on the WS2801. It would take almost a full 2.5ms to get it to work right. Add the 1.2ms from the uSD and I was looking at close to 4ms for each update on the string. That was way too long.
I've now switched to an LPD8806 design and thanks to the strip that Ryan sent, I was able to both confirm my suspicion as well as continue development. Here are some other images taken using the LPD8806 strip:
I forgot! I'm driving the strips off of a single 3.7V Li+ battery! Even though they are, technically, 5V strips, running them at 3.7V (nominal) works just fine. The battery charges up to 4.2V and discharges down to 3.0V ... though I haven't reached that yet. After about an hour of running a constant cycle of about 14 images, each being displayed for 5-10 seconds, the battery went from 3.72V to 3.66V.
Yep. I have the PCBs and ICs already in hand. The LEDs were delivered today. Waiting for the stencils and caps to arrive on Friday and then I'll whip up a custom "string" that has 48 pixels packed together 29cm long.
I spent yesterday making one of the four strips I need for the final unit. I forgot what it pain it is to solder SMD by hand. I did the ICs and capacitor on one side, and all the LEDs on the other side using a skillet reflow method. That meant hand soldering 48 5050 sized LEDs on the other side. Oy vey. Not impossible, but trying to align them while soldering just wasn't happening. But I've also discovered another issue with the lower voltages that I'm using so I'm probably going to get some new boards made for the next revision, as well as using thicker ones. I went for 0.8mm but they warp a little when I reflowed the ICs on. So the next revision will have slightly thicker PCB and slightly larger pads on the LEDs side to make soldering just a tad easier ... maybe. Still trying to figure out how to get the LEDs aligned neatly prior to soldering. I could do it if I was reflowing the LEDs, but then I'll have to hand solder the 12 ICs on the other side. Not sure what's easier ...
Anyway, with a actual size strip built, I'm able to pretend I'm spinning it (in reality it's on the ground and the camera's spinning, same effect though):
If you don't mind switching to a different chipset
AU $54.99 what's that these days? $50 USD? for a 5meter strip...
Strip length: 5M
LED: 150 x Light Emitting Diodes
LED type: 5050 SMD LED
Chipset type: 6803 IC
Power: 36W (7.2W per meter)
Light color: RGB multicolor
Lighting angle: 120°
Working voltage: 12V DC
Waterproof grade: IP68
IC qty.: 10 pcs per meter
I just ordered 50 addressable LED's (chip sits inside the LED) and i plan on using SMD components to make a light up jewelry.... Ideally I want something smaller than 5050 with an inbuilt ic more like 1206 sized addressable leds
I guess these days if you buy something at a bargain just 6 months ago, they've already manufactured so many more the price comes down...
