I’m trying to use the OpenCM 9.04 as an SPI slave that receives a buffer from a separate board (ESP32), parses it and actuates the motors. I’ve navigated the interwebs as much as I can but it kind of seems like I cannot run even the ‘Hello World’ example described here for two Arduino UNOs: Arduino - Serial Peripheral Interface
Unfortunately, the OpenCM9.04 does not have SPI Slave implementation.
However, if necessary, you can modify the SPI driver based on the included stm32 hal library.
According to the OpenCM9.04 schematic, SPI1 and SPI2 channels are available.
Here’s some useful information for this implementation.