- use `@image` instead of inline images for better aesthetics,
especially on mobile form factors (where the image before overflowed
the screen width)
- add pinout diagram
- use correct units
Using `sched_switch()` in `mutex_unlock()` can result in crashes when
`mutex_unlock()` is called from IRQ context. This however is a common
pattern in RIOT to wake up a thread from IRQ. The reason for the crash
is that `sched_switch()` assumes `thread_get_active()` to always return
a non-`NULL` value. But when thread-less idle is used, no thread may be
active after the last runnable thread exited. Using
`thread_yield_higher()` instead solves the issue, as
`thread_yield_higher()` is safe to call from IRQ context without an
active thread.
This fixes https://github.com/RIOT-OS/RIOT/issues/20812
This patch exports the make macro `DEVELHELP`. Without this patch, use
of the macro in the following files does not work when the macro is set
in a makefile (such as in Makefile.local or an application's makefile as
demonstrated in dist/Makefile). Inside these files `DEVELHELP` is not
defined under these conditions.
- pkg/littlefs/Makefile
- pkg/littlefs2/Makefile
- sys/stdio_null/Makefile
Note that use of the macro does work in these files when the macro is
set from the command line, without the patch. For example:
``` sh
$make DEVELHELP=1 all
```
This implements the `shield_llcc68` module that allows using the LLCC68
LoRa shield on Arduino UNO compatible boards (with Arduino IO mappings
provided by the board) by just selecting the module.
The Arduino Zero based boards already provided the feature
`arduino_spi`, but were missing the corresponding mapping. This fixes
the issue by adding the SPI bus numbers for the ISP SPI bus and the
D11D12D13 SPI bus.
(And in order to actually add the D11D12D13 SPI bus, the `periph_conf.h`
was extended to provide an SPI configuration for it.)
We cannot just decrement the reference counter of power modes without
any coordination. First, this will trigger an `assert()`ion on non
STM32 MCUs that have power modes that are not used (the ref count would
be decremented below zero). Second, there hopefully is a reason a
certain power mode is blocked, e.g. because a periph driver needs a
certain clock to function.
Likely the `periph_uart` driver on STM32 boards keeps power modes
blocked after TX is completed even when no RX callback is present, which
is the waste of power this hack tries to address. But that should be
addressed there.
