I know this forum is all about FastLED but thought since you guys/gals have way more experience with this stuff than myself at this moment I’d ask for some thoughts. I tried hooking up three strings of 16’ 2812B’s they run at 5V and was not having very good success getting the last half of the string to get it’s data. I was told that some other options for LED’s might be better running at 12V and maybe a clock input, I’ve also decided to go with a different controller like a T-1000S that I can design my show/string with a visual interface rather than code. LedEdit2017 is going to be a good option I think.
My question is what’s a good source for such a string? I can only find 2801’s that have a clock pin but they run at 5V. I’m thinking the 12V will help get that data further down the line (as far as I understand).
Anyone with some thoughts? I’m just trying to get 3 strings of lights for Christmas on the front of the house this year
@Mike_Katchmar They just didn’t do what they were told to, maybe some flickering, maybe some not lit up. Even with injecting power down the line they got brighter but not consitent on the data side it seemed. Could have been something else not sure. But I’ve sent it all back paid extra shipping as nothing was technically wrong I guess. These were what I was using at first https://www.amazon.com/gp/product/B00ZHB9M6A/ref=oh_aui_detailpage_o04_s03?ie=UTF8&psc=1
Applying 12V to a strand of LED’s that use 5V is a bad thing. Sort of like hooking your TV set up to 240V instead of 120V, or revving your car engine up to 10,000 RPM.
That being the case, 5V strips of LED’s are fine. You just need to power them at both ends and make sure ALL grounds are connected to each other. For longer lengths, i.e. > 150 LED’s, I’d probably be using WS2801 or APA102 instead of WS2812’s.
@Andrew_Tuline Do you have a good source for 2801’s or APA102’s in 150 led strings that are waterproof for outdoor? If I have 3 strings of 150 I’m at 450 min and that’s where I was seeing the data loss it seemed.
I’ve run those exact same strips that you linked to for over 80’ (>700 LEDS) with no problem at all, powered from an Arduino Mega or Particle Photon. The color/brightness does suffer (unless you inject power) but the LEDS should be obeying the data commands w/ no problem. Like Andrew suggests, maybe it’s a grounding problem?
@Ryan_Cush Thats reassuring. I’ll admit it was just a test setup so nothing was soldered or anything. I wish I would have spent more time figuring things out! I just got scared! lol. Thanks for the feedback. Your talking about the alvin’s right? Running at 5V.
If you need stuff for the holidays I would avoid ebay’s international sellers and aliexpress, it may not make it in time. There are several strip & waterproof options on Amazon that are 3 LEDs per 1 chip, which reduces your resolution, but they are Prime and ready to ship at a decent price.
I have no vested in the site below, but I’ve seen other people on another forum use it with success. They may also be busy at this time of year, but they have several LED strip products with waterproofing: http://www.holidaycoro.com/Smart-Pixel-Ribbon-Strip-Tape-s/1961.htm
Alvin’s? Soldering the strips together might give better performance. Also I used to inject power from both ends, but then I found that it worked better to inject at the start of the strip and then about 2/3 of the way down. That way, the secondary injection feeds the end but also feeds the middle.
@Ryan_Cush oops, alitove! Yea that’s exactly what I did with the three I had. Data from Arduino running demo FastLED hooked up with bare copper solid strand to the beginning of the 3 strips. Then injected more power at the start of the third, everything got nice and bright! But the end of the third strip was doing wierd things blinky etc… not following commands.
5V is appealing if it will work well. I had bought a 5V 60A supply to go with the setup. I might just give it another try! I didn’t send the Arduino back, so I might pick up the t-1000S just for kicks and try the arduino FastLED option as I had time.
Cool. Keep in mind that at some point you’ll exceed an Arduino Uno’s memory and will need to use a Mega. I think that happens around 500 or 550 LEDs. Also, if you’re feeding the secondary power injection from the power supply at the start of the strip, make sure you use good thick wire to carry that power so that it doesn’t drop over the run. Something like 12/2 landscape lighting cable.
@Ryan_Cush Yea my Arduino was the Mega I had read about it running out of memory. I did buy thicker wire I’m pretty sure it was 12ga. Now just trying to organize my order so it all comes in at the same time. They all said prime but some items were not two day shipping…go figure! lol.
Going through this thread, I also think you were experiencing a voltage drop along your strips and nothing to do with data problems.
The WS2812 regenerate the data it receives for the next device. In theory, you could have thousands of WS2812 in series as long as your controller has enough memory for the pixels data ( 3 bytes per pixels ) and all other variables used in you sketch. A MEGA with it’s 8Kbytes of ram should handle over 2000 pixels if your sketch is not too complex.
However, 2000 WS2812 pixels would take forever to update. You could not update them more than 16 times per second but in some cases that could acceptable !
The key here is to ensure that the voltage at any point in your setup does not drop below 4.5 Vdc. The operational specs for the WS2812 are only specified for voltages between 4.5Vdc and 5.4Vdc.
Still… note that it is possible to have the voltage drop to 4Vdc or even lower AND have them working somewhat but it is outside of the specifications for the device and you are just taking a chance.
If you intend to run your strips at full brightness white you may find that you need to inject power every 3 or even 2 meters to not notice any ‘data’ problems or significant brightness difference between pixels in your complete setup.
