Hello, Thanks to your help i have been able to compile and install ESPixelstick sketch on my Nodemcu with the good frequency. I am impressed by the GUI which allows you to configure the LED, WIFI, Multicast, MQTT and test effects (rainbow and so on), that's perfect ! Now just to double check : You mentioned that the GPIO 2 is used, i think i tried with the wrong one, i connect D2 which is different from GPIO2. Here is a picture of what i should connect : All the GND should be connected with the GND of the LED power supply. The GPIO2 which is printed as D4 on the Nodemcu, this one should be connected to the level shiftter (or directly on the LED strip for "bad testing") On hyperion, i should use the udp type and specify the IP address of my nodemcu. Am i correct ? Thanks !