* I've bought 3 x 1507 (144 rgb ) which I cut to have 6.
* I've connected all of them to a fadecandy and to a 5V/5A wall power supply.
* I'm using the test patterns from the FC server page.
The issue : 3 strips are properly display white colors, some of the others are displaying some colors (randomly) and some nothing.
So I've used another FC to check that it's not the problem with only 2 strips.
Same : the strip that was ok is still ok , and one of the wrong strip still wrong.
The picture shows it well:
with no pattern some weird colors for the bad strip + 1 led (!!) for the good one
with 50% pattern : the good diplays everything properly + the wrong is not changing
I would test each (half) strip with a simple test. One of the neopixel examples will do. No fade candy, just a simple board (even an Arduino UNO should do) to test the basic function of each strip. Describe precisely how the problematic strinps behave.
Last question : but what if after the half that have been cut : it still doesn't work properly while testing like you propose ?
I've been reading the Uberguide / tech detail / etc . and I understood that it was easily possible to cut a strip to make 2 .
I never found anything to set a common ground between the power supply and the strip when using the FC so ...
Yes, cutting them should not cause a problem. Hmm.. can you post clear, closeups of the ends where you chut, and where you've connected to the resulting strips.
Hmm again, the half strips that are causing a problem.. are you connecting to a cut end on them as opposed to the original wired end?
OK. Each end of the strips is different. One end has Data-in... the other has data-out. You need to connect to the data-in sides. So in half the cases, that will be the cut end.
Connecting the data from the FC to the Data-in of the strip will probably fix your problem barring anything other issues, though no damage should have been done by the connection to Data-out.
Why did you do that? black is ground and white is signal (generally)... is that how they are connected on the FC?
You nned to connect the data signals from the FC to the Data-in end of the strips. As you say, there are arrows that indicate the flow of data through the strip. The arrows point from the Data-in end to the Data-out end.