How to use 3-wire SPI on BMP3 sensor

Hi everyone,

For my master's thesis, I designed a PCB with Bosch BMP384 sensors. In my previous version, I utilized 4-wire SPI for communication. However, in the newest version, I decided to switch to 3-wire SPI. I am using an Arduino to communicate with the sensors, and I found a GitHub repository from Bosch that explains how to write code for sensor communication (https://github.com/boschsensortec/BMP3_SensorAPI). The GitHub repository only provides code examples for 4-wire SPI and does not cover 3-wire SPI.

The sensors uses 4-wire SPI by default,  to use 3-wire SPI, bit 0 of register 0x1A needs to be changed from 0 to 1. I have tried multiple approaches, but I am unable to make it work. Does someone have an example of how to set up 3-wire SPI communication with a Bosch sensor?

Thank you in advance.

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