As we're around here, lets see how fast this implementation is.
All measurements are raw reading performance, without actual
parsing of the G-code.
With SPI_2X disabled (see line 8 in spi.h), performance is
195 seconds per megabyte, equivalent to about 50'000 baud.
With SPI_2X enabled, performance is 159 seconds per megabyte,
or 60'000 baud.
Still, SPI_2X is left disabled to increase reliability. Reading
from SD is faster by design, because there is no checksumming and
also no waiting for the "ok" to be sent back. In case reading
G-code from SD ever becomes a bottleneck, there are even more
opportunities in addition to enabling SPI_2X, like making sdbuffer
bigger, like micro-optimizing spi_rw() and similar stuff.
##############################################################################
# #
# Teacup - lean and efficient firmware for RepRap printers #
# #
# by Triffid Hunter, Traumflug, jakepoz, many others. #
# #
##############################################################################
For installation instructions, see
http://reprap.org/wiki/Teacup_Firmware#Simple_Installation and/or
http://reprap.org/wiki/Teacup_Firmware#Developer_Installation
For documentation, see
http://reprap.org/wiki/Teacup_Firmware
##############################################################################
# #
# This firmware is Copyright (c) ... #
# 2009 - 2010 Michael Moon aka Triffid_Hunter #
# 2010 - 2013 Markus "Traumflug" Hitter <mah@jump-ing.de> #
# #
# This program is free software; you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation; either version 2 of the License, or #
# (at your option) any later version. #
# #
# This program is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program; if not, write to the Free Software #
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA #
# #
##############################################################################
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