I now have stock of USB-RS485 (USB-DMX) dongles back in stock. I ended up having to get them custom made as no-one seems to stock them any longer. The new style have send and receive leds and are wired as per the ESTA pinout to a RJ45 male connector. I am shipping them with a RJ45 female-female joiner. http://www.hansonelectronics.com.au/product/usb-dmx-dongle/ These are open-dmx compatible and work with light-o-rama, lightshowpro, vixen, xlights and of course da-dmx. They should also work from a Raspberry Pi running FPP but I haven't tested that as yet.