Quick question. I’m new to all of this and I have finally gotten my around to testing the library out. It works great except that for the blink program after a few times going through the cycle it start to display all sorts of weird colors and not just blink red. I was wondering if i could get some help. Right now i’m using pl9823 on a nano with the program set to ws2812. Thanks for you help guys.
How many pixels?
How do have things wired up and how are you powering the pixels and the nano?
I have 6 pixels. The first and last seem to be the only ones screwing up. No capacitors or resistor. I’m powering it of a 5v 25 watt power supply attached to a bread board.
I was going to ask if you have the grounds of everything connected together? I guess you do if everything is being powered by that single power supply. Grounds of LED strip and the controller must be connected together.
Adding adding a 1000uF cap near the start of the LEDs, and a resistor on the data line can be your next test. 
How far away are the LEDs from the Nano? Have you checked the voltage at the beginning and end of the LEDs?
Alright thanks for the help. They did not have a common ground and the did the trick.