To the average microcontroller, Ethernet networks are quite a step up from the basic I2C, SPI and UART interfaces, requiring either a built-in Ethernet MAC or SPI-based MAC, with tedious translation between Ethernet and those other interfaces. Yet what if this translation could be done automatically and transparently? This is what the SatCat5 FPGA-based project by [The Aerospace Corporation] aims to provide: a gateway akin to an unmanaged Ethernet switch that also supports those non-Ethernet links. Recently they answered a range of questions about the project on Hacker News.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/04/01/satcat5-uart-spi-and-i2c-via-ethernet-with-fpga-based-design/