collapseos/doc/hw/spi.txt

# Communicating through SPI

Many very useful device are able to communicate through the SPI
protocol, for example, SD cards and AVR MCUs. In many cases,
however, CPUs can't "speak SPI" because of their inability to
bit-bang.

In most cases, we need an extra peripheral, which we can build
ourselves, to interface with devices that "speak SPI". We call
this peripheral a SPI relay.

The design of those relays depend on the CPU architecture. See
spi.txt in arch-specific folders for more information.
Complete overhaul of recipes Recipes contain bits and pieces of hardware-related knowledge, but these bits feel sparse. I've been wanting to consolidate hardware- related documentation for a while, but always fell at odds with the recipes organisation. We don't have recipes anymore, just a /doc/hw section that contains hardware-related documentation which often translate to precise instructions to run Collapse OS on a specific machine. With this new organisation, I hope to end up with a better, more solid documentation. 2020-10-31 11:31:47 +11:00			`# Communicating through SPI`

			`Many very useful device are able to communicate through the SPI`
			`protocol, for example, SD cards and AVR MCUs. In many cases,`
			`however, CPUs can't "speak SPI" because of their inability to`
			`bit-bang.`

			`In most cases, we need an extra peripheral, which we can build`
			`ourselves, to interface with devices that "speak SPI". We call`
			`this peripheral a SPI relay.`

			`The design of those relays depend on the CPU architecture. See`
			`spi.txt in arch-specific folders for more information.`