system_state.fmu_data_received_time can be set from an IRQ handler, thus
we need to ensure every read access to it in mixer_tick is atomic.
So we read it once and copy it into a local variable.
The controls_tick() rate exceeds the rate at which RC receivers
provide digital rssi. As such, most ticks set PX4IO_P_RAW_RC_NRSSI
to 0.
This change promotes the controls_tick() local variable 'rssi' to
static storage so that it doesn't have to be updated every tick to
keep the correct value in PX4IO_P_RAW_RC_NRSSI.
On SPM4649T receivers with firmware versions at least 1.1RC9, the
serial data will contain an rssi value in dbm, as outlined in the
Remote Receiver Interfacing document section 8.3.1.
If the value received is greater than or equal to zero, the receiver
does not support rssi data, and the incoming value will be ignored.
However, if the value is negative, we can use the rssi value.
When we have a valid rssi, it gets mapped to a percentage from 0 to
100 as expected by mavlink. This mapping is constructed as a
logarithmic function over Spektrum's published minimum and maximum
rssi values, -92dBm to -42dBm as 0 to 100:
100 Log10[1 + (x - min) * (9 / (max - min))]
This change updates all calls to the dsm input rountes to return
the rssi value.
Note that one place this doesn't work with the px4io enabled.
There is a comment left in the absence of analog rssi that:
"we do not actually get digital RSSI regs[PX4IO_P_RAW_RC_NRSSI]".
This restriction has been left in place, as removing it exposes a
problem where the frequency of the control tick is greater than
that of valid dsm frames so the rssi isn't valid every cycle.
The mixer was creating a new class in interrupt context, which is not valid use in NuttX. This change copies the mixer into the buffer and runs the mixer management section of the code outside of interrupt context in the normal task.
* NuttX cmake
* px4_macros:Pass the stringified predicate as second arg to static assert
CC_ASSERT mapes to the c++ static_assert or provides the same
funtionality for c via the other macros. The c++ static assert
takes 2 argumants the prdicate and a message. This fixes the
lacking second argument.
* Updated nuttx and apps submodule to upstream nuttx 7.21+==master
This is the latest uptake of upstream nuttx and apps.
* ROMFS generate with xxd instead of objcopy
* delete nuttx-patches
* NuttX update submodules to latest px4_nuttx-master
* fix nuttx apps and board dependency
* docker_run update to latest container 2017-08-29
* cmake ROMFS portable sed usage
* NuttX update submodules to latest px4_nuttx-master
was:<nuttx/arch.h> is:platform/cxxinitialize.h
Removed PX4 version:src/modules/systemlib/up_cxxinitialize.c
in favor of nuttx platform/gnu/gnu_cxxinitialize.c
was:<nuttx/arch.h> is:platform/cxxinitialize.h
Removed PX4 version:src/modules/systemlib/up_cxxinitialize.c
in favor of nuttx platform/gnu/gnu_cxxinitialize.c
bresch