Hi, need some help. Black is not Black 
Before I was using strings of WS2811 5V pixels (and those are working fine) Recently I bought strings of 50 ws2811 12V pixels.
Pixels powered with 12V. Arduino nano powered with 5V. no level shifters for the datapin => also 5V (and common GND).
Problem is that the pixels never go to black but stay in a kind of light orange.
If I use the ie the firstlight with the max number of pixels (50 then you see the white pixel go from the first until the last pixels but when it the pixel has to become black it becomes a kind of orange.
I tried a all the different pixel types in the RGBcalibrate but didn’t find one that solves the issue.
Any suggestions
Hmm - it sounds like there might be a timing issue that’s causing the 12V WS2811’s to always interpret one or more of the low bit 0’s as a 1.
Two questions: what version of the library are you using? and Do you have something other than a nano (e.g. an uno) to do a quick test with?
Using 2.1 form a few weeks back.
Did just now the test with an uno and same behaviour.
Ok - there might be something off with the timing then when using 12v pixels. I don’t have any 12v pixels handy, but I believe @Mark_Kriegsman does.
In the meantime, could you grab the latest release of code from http://fastled.io/releases (3.0.1) and try that, just to make sure this wasn’t something that got fixed in recent changes before the 3.0 release.
Installed the 3.0.1 and same behaviour.
additional remark. when I use the firstlight script with the max nr of pixels I see that the last pixel after it came white it is for a short time green/yellow than red and then towards the same soft orange/red as the other pixels
Yeah, that’s more of a sign that signals are being read incorrectly by the strip. And you are sure these are 800khz ws2811 and not 400khz?
Also - have a link for where you got them from?
Not sure about the freq.
and not specified http://www.aliexpress.com/snapshot/6292667140.html
For laughs try WS2811_400 in the meantime I will try to track down some 12v strips to test.
when using WS2811_400 with the firstlight script all pixels are bright white and no moving dot …
Ok, so you definitely have the 800khz strips, then. Also - what version of the arduino software are you using?
Arduino soft : 1.0.5…
Can it make a difference ? the 5v ws2811 is working correctly (same nano, same sketch)
Only if you were using Arduino 1.5.7 or 1.5.8 
I’m going to try running off of an uno on a logic probe to see if any of the specific bits have timing that looks like it might be off enough to confuse things.
Connected a 5v & 12v to the same nano. bouncing ball script with the 2 strips in mirror (on different datapin)
on both you see "the balls bouncing"simultaneous but on the 12v instead of dark pixels I have light red…
=> need to be specific too those 12v…
I bought 5 of them, tried 2 of them and same behavior…will solder now the connectors on the remaining 3 to test …
Blah - i’m not seeing anything on the logic probe trace that could indicate a problem. Feel like trying a couple of experiments to see what might help?
If so - the first one would be go to line 377 in chipsets.h in the library:
class WS2811Controller800Khz : public ClocklessController<DATA_PIN, 2 * FMUL, 5 * FMUL, 3 * FMUL, RGB_ORDER> {};
try changing it to:
class WS2811Controller800Khz : public ClocklessController<DATA_PIN, 3 * FMUL, 4 * FMUL, 3 * FMUL, RGB_ORDER> {};
and see if that helps/changes anything.
Alternatively, try changing it to:
class WS2811Controller800Khz : public ClocklessController<DATA_PIN, 1 * FMUL, 5 * FMUL, 4 * FMUL, RGB_ORDER> {};
Also - some people have recommended putting resistors on the data line - http://forum.pjrc.com/threads/24648-Newbie-findings-re-WS281X-signal-quality(wire-length-resistors-and-grounds-Oh-my!) - it’s possible the 12v WS2811’s are more sensitive to these issues?
Found the rootcause (not yet the solution …)
I has to do with the power…
when connecting a 12v powersupply (12.26V) its working correctly. when connecting the 12v Battery (10x NiMH) (12.94V) it has that strange behavior
@Daniel_Garcia you are great. Just saying.
bummer, I switch to 12V strips because I thought/hoped they were a little more tolerant in the voltage.
I hoped that I could use ie cellcoin powered arduinos (rfduino, aurbee, …) to drive the data, and power the strips with my 12v - 14.4v batterypacks that I recuperated from old UPS devices.
Second bummer I use those nice cheap Benq 12v-5v-3v buck converters to power the nanos and 5v strips. Doc is a little misleading. I interpreted it that it also had a nice regulated 12v output but this doesn’t seem to be the case.
Conclusion : Sticking to 5v strips would have been an better option in my case.