3-Wire SPI Device Integration

ArduCopter
1

I’m looking to implement a new device into the Pixhawk’s STM board. The device in question only communicates through I2C or 3-wire SPI communications. Are there any examples of Ardupilot using 3-wire SPI devices in the drivers?

2

I might be wrong, but implementing a 3-Wire SPI solutions implies adding some hardware to share the MISO-MOSI lines:

So maybe adding hardware and using a GPIO line (RC_OUT) -or- interfacing to an Arduino (or STM108 BluePill) and sending data back as either 4 lines SPI or I2C or as MavLink on serial could me an alternative ?