How to connect this sensor via SPI?

Question

Electronics

Magnetometer sensor IIS2MDC
Port 1 - understandable
Port 3 - understandable
Port 4 - understandable. For SPI, here is SDI, but where is SDO?
I am doing work for a university, I have already made many different sensors, but this is the first time I have encountered the lack of an SDO port. How to be? Why is that? Or if I'm missing something, please explain!

Answer 1

There, half-duplex, SDI and SDO go on the same wire. When the master needs to transmit, it switches this pin to the output, when it should receive - to the input. In many controllers this is already implemented in hardware called "Half-Duplex SPI", "3-wire SPI" or something similar.
If your controller does not know how, you can either pull SPI programmatically, or connect MISO directly, and MOSI through a resistor. https://www.totalphase.com/support/articles/200350...