This board connects the USB HS interface to the micro usb connector as
opposed to the USB FS interface on the stm32f4-discovery board. This is
why we are using different pins, different periph and different driver.
At the end it should(TM) behave the same as the HS interface implements
FS too.
Tested on STM32F4Discovery with Linux host using both amidi (raw
messages to/from device) and a synthesizer (note on/off) and on
Windows 7 using MIDI-OX.
Presumably code that attempted to toggle a led, but it wasn't setup, and it's
not in any other examples. Kill it for now.
Reported-by: stefanct on irc.
While nano specs are certainly handy, it should be documented how to use them,
not turned on by default. People with otherwise valid toolchains, who might
simply not care about nano specs are unable to build the examples with these
options.
While some of the examples include a "board.ld" style file, some of them were
pointing to the libopencm3 provided chip specific ld scripts. When
TOOLCHAIN_DIR has been overridden, those paths were no longer valid/correct.
The Makefile.includes contain a hardcoded ../../../../../libopencm3
path for the TOOLCHAIN_DIR variable. They also contained another copy
of this hardcoded path, that is now generated from $TOOLCHAIN_DIR.
This allows to have a symbolic link to a Makefile.include in an
out-of-tree project and reuse the Makefile infrastructure.
This is not specifically an L1 example, but it lives beside the L1 "usart"
example to show how easy it is to add semihosting support to existing code.
Tested with the by now relatively old g-a-e 2012q4 release and
OpenOcd 0.8.0-dev-00011-g70a2ffa (2013-05-14-19:41)
as a way of creating accurately timed delays. A simple 'msleep'
is implemented by watching the system clock to wait a certain
number of milleseconds before it returns. Its a bit more accurate
than a for loop, although it really shines when your running multiple
threads.
This example is a merge of Chuck McManis's example for F4 and onnokort's system clock setting test blink example for demonstration issue, corrected in #224.
The LED in any available clock setting flashes four times per second.
Piotr Esden-Tempski