SPI with differential line drivers, and star configuration problem
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SPI over long distance

Raspberry PI&#39;s SPI over RS485

It seems that it's a common practice to use RS-485 transceivers to transmit SPI over long distance.

If I understand it correctly, you are not exactly creating a star topology, but rather multiple point-to-point connections. You will have differential pairs for each SPI signal on each SPI device and for each pair you will have two transceivers (one on each end). So there will be no single potentially overloaded RS-485 transceiver, the reason why star topology is not recommended.