[kfogel]

AHHHH, that's the key thing I didn't know (I have a Raspberry Pi sitting in a drawer and have played with it embarrassingly little -- I didn't realize how important having the SPI or other special interface is in this context). Thank you again.

[sethhochberg]

With that said, though, there are also tons of inexpensive ways to output SPI or various other serial protocols from just about any device with a USB port, like your full-sized computer: https://www.adafruit.com/product/2264

The RPis and friends just optimize the workflow - theres nothing particularly magic about they way they implement SPI or GPIO, they just have it out of the box because its such a common way to extend hobby computer boards.

[kfogel]

Just ordered. Thank you :-).