I have a Arduino Mega hooked up to a WS2812B light strip and am using FastLED to control it. I have a 330 ohm resistor on the data line of the light strip. I also have an IR Receiver on another data port and a sound sensor on an analogue port.
When I draw power for the led light from the Arduino itself (via USA port of computer) everything works as I expect. The led lights turn on and off according to the program. However, as soon as I switch the led strip over to an external power supply (5V40A) and the the Arduino sends a signal to turn on the led lights the whole string lights up with random colors.
I initially didn't have the 330 ohm resistor on the led data line so I added that thinking maybe this was a noise issue but it give the same results. Does anyone have any idea what I might be doing wrong?