@Yveaux said in nRF24Doctor: I've run multiple gateways using W5100 on hw spi with atmega328 and never had any issues apart from that SD card select line. Very interesting. I just (few weeks ago) built an Ethernet gateway recently and at the time followed the recommendation for soft SPI. Then more recently I read about hardware SPI being required for MY_RX_MESSAGE_BUFFER_FEATURE which of course would be a valuable feature on a gateway. @benbidouille, Did you ever investigate further? Even if not, I will probably do so on my own, sooner or later, as I have a few of the various W5500 cheap modules here...