Arduino for STM32

i took a look at the specs, it says 10 Mhz max for SPI bus.
https://www.microchip.com/en-us/product/MCP23S17
use spi.BeginTransaction, pass a SPISettings with a lower speed like 10 Mhz to see if it helps.
defacto SPI speeds for stm32 is like 50 Mhz, everyone assumed u'd need it to go 'as fast as ...

Hi everyone guys, i've a problem keeping MCP23S17 in SPI mode working with my bluepill. I'm using the official arduino STM core (not the roger one) and this library https://github.com/MajenkoLibraries/MCP23S17 . I've modified this library in the readPort(uint8_t port); function adding a parameter ...