I've never used SPI before (for serial communication) and was wondering if any experienced Pi users out there know if the Pi board can use SPI to send and receive data to other MCUs on different boards.
If so, do these other boards need to be Pi's as well? Or can it be any other SPI-capable board?
How does SPI communication work on a Pi? Does it work in the form of user-level terminal commands, like:
// Turn a green LED on send_to_spi 0x39943
Or is it something that has to be written in C and exist inside a running application? Any concrete examples or articles with concrete examples are greatly appreciated.