No code changes, just file, variable and define names are changed.
First, it better describes the serial protocol used by DSMx satellite
receivers. Second, many people using Spektrum radio, assume Spektrum
protocol. This is the attempt to address those inaccuracies.
In the previous version the decoder could in rare cases get synced from
the middle of data stream in case of data byte equal to the S.Bus start
of frame (SOF) byte (wrong data will be rejected but it was not perfect).
Now it waits for the real start of frame and then checks the SOF byte.
PWM and PPM can now coexist in the same load and be
selected at boot time via the hwsettings UAVObject.
This is basically a complete restructuring of the
way the drivers interact with the TIM peripheral in
the STM32.
As a side effect, the PWM and PPM drivers are now
ready to support multiple instances of each.
This also provides the first step toward being able
to reassign some of the PWM input pins to be servo
output pins. Still more work required, but this is
a good start.
This allows the spektrum and sbus receiver drivers to bind
directly to the usart layer using a properly exported API
rather than overriding the interrupt handler.
Bytes are now pushed directly from the usart layer into the
com layer without any buffering. The com layer performs all
of the buffering.
A further benefit from this approach is that we can put all
blocking/non-blocking behaviour into the COM layer and not
in the underlying drivers.
Misc related changes:
- Remove obsolete .handler field from irq configs
- Adapt all users of PIOS_COM_* functions to new API
- Fixup callers of PIOS_USB_HID_Init()
Each channel was previously tracking a separate driver.
Now, channels are grouped within a channel group to save
RAM used for tracking and to better reflect how channels
are actually mapped.
The initial baud rates of each interface are now forced in the
board init code.
Any modules using USARTs should have fields added to
their settings object to allow the user to change the
baud rate from the default by using the COM layer APIs.
Developers requiring custom baud rates before the settings
objects are in place should locally edit the cfg structs
to specify the desired baud rates.
This should mark an end to the compile-time selection of HW
configurations.
Minor changes in board initialization for all platforms:
- Most config structs are marked static to prevent badly written
drivers from directly referring to config data.
- Adapt to changes in .irq fields in config data.
- Adapt to changes in USART IRQ handling.
Major changes in board initialization for CC:
- Use HwSettings UAVObj to decide which drivers to attach to
the "main" port and the flexi port, and select the appropriate
device configuration data.
- HwSettings allows choosing between Disabled, Telemetry, SBUS,
Spektrum,GPS, and I2C for each of the two ports.
- Use ManualControlSettings.InputMode to init/configure the
appropriate receiver module, and register its available rx channels
with the PIOS_RCVR layer. Can choose between PWM, Spektrum and PPM
at board init time. PPM driver is broken, and SBUS will work once
it is added to this UAVObj as an option.
- CC build now includes code for SBUS, Spektrum and PWM receivers in
every firmware image.
PIOS_USART driver:
- Now handles its own low-level IRQs internally
- If NULL upper-level IRQ handler is bound in at board init time
then rx/tx is satisfied by internal PIOS_USART buffered IO routines
which are (typically) attached to the COM layer.
- If an alternate upper-level IRQ handler is bound in at board init
then that handler is called and expected to clear down the USART
IRQ sources. This is used by Spektrum and SBUS drivers.
PIOS_SBUS and PIOS_SPEKTRUM drivers:
- Improved data/API hiding
- No longer assume they know where their config data is stored which
allows for boot-time alternate configurations for the driver.
- Now registers an upper-level IRQ handlerwith the USART layer to
decouple the driver from which USART it is actually attached to.
All receivers now fall under the same driver API provided
by pios_rcvr.c.
This is part of a larger sequence of commits that will
switch the receiver selection over to boot time dynamic
configuration via UAVObjects.
