hello, on my ws2815 strip is only every 2 led on.
What am I doing wrong?
Is that with solid effect in wled?
It doesn’t matter whether I set a fixed color or an effect, it is always only shown every 2.
I connected the data line to pin DI on the strip. And every 2 LED is controlled.
when I connect it to BI, every led except for the last one is controlled.
Sounds like your strip may be bad.
BI is the backup line, and you should connect it to DI.
I have found the mistake.
I have 30 LEDs, if I set 30 LEDs in the LED settings, the last one stays off.
When I set 31 the last led lights up
Is that a bug in the software?
No, the last number is not part of the group. Check the wiki. 
I looked around the wiki, but found nothing suitable for my question / problem (why the last LED stays off). tonyno what do you mean exactly?
I found the correct connection for the data line in the wiki. It’s B0 and not D0!