I am using an ATMEGA48 device with several SPI parts. I have hooked up single devices to SPI in the past, just blindly going about it & working well.
Now, however, I need to hook up 3 different devices---can SPI handle this? I'm not sure how each of the different devices is "addressed"---so that writing to one doeesn't cause a write to the other. All of the various notes I see refer only to hooking up one device--which is all i needed in the past.
Looking at the datasheets seems to indicate that each device needs a separate I/O select line (Slave select) from the cpu---this seems wasteful if a lot of SPI devices (say 7) were being used.---I was under the impression that only 4 lines would be needed regardless of the peripheral total.
Any tips or comments appreciated!