Hello, issue with flicker, read that it’s important to have same GND but don’t understand in detail, not enough with same group in electric central? Here I done some wiring, first one is how it looks for the moment then some idea from my side. I use rs485 TTL for long signal distance below 10m. strip one 5m and strip two 5m. Green=signal. Hope someone here can help me soon 
Pictures in wrong order, using “1“ now. ESP 32.
need common ground
1 Like