For now this is just a nice demonstration on how to send bytes
over SPI. Add SD_CARD_SELECT_PIN to your configuration board
file manually to see data signals on MOSI dancing on the scope.
The TODO's about SS in arduino*.h were wrong, SS does have a
chip-specific special meaning (used in SPI multi-master or SPI
slave mode). Still, a #define MAX6675_SELECT_PIN is missing.
Squashed in this commit from the SPI development topic branch to
get this first step working:
Author: jbernardis <jeff.bernardis@gmail.com>
2015-02-04 22:35:07
mendel.c: disable SPI in power management only when not needed.
If we want to talk to a SD card connected to SPI, we need SPI
powered, of course.
From Traumflug: nice catch, Jeff!
This is mostly for less confusion, because analog pins can
be used as digital ones, too. It also matches what other firmwares
do, so people can simply copy & paste pin definitions.
Definitions were taken from Sprinter's fastio.h (which was
initially crafted by copying Teacup's arduino*.h files :-) )
Eventual debugging LEDs aren't part of the CPU, but part of the
electronics. Accordingly, define it in config.*.h, not in
arduino_*.h (which would be better named something like
"atmega_*.h).
Markus Hitter
Mikko Sivulainen
Michael Moon