How easy is SPI with the OSHChip? I thought I'd find out by first controlling a module that has a very basic SPI-ish slave interface.

I'm using the LEDx16Module that I designed in the KiCad like a Pro course from Tech Explorations. It has dual 74HC595 shift registers that can be driven with SPI to control 16 onboard LEDs.

As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub.