Does anyone can help me to figure out witch the spi pin is on the sockets of a Fex Raptor. I want to connect a WS2811 Led strip to it.
SPI is an S socket. The socket quickref is the best way to find your pins: https://www.ghielectronics.com/docs/305/gadgeteer-sockets-quick-reference
You may also find this code useful in driving the WS2811: