The Silicon Labs Si705x sensors (Si7050/1/3/4/5) are very similar to the
Si7021 sensors featuring only a temperature sensor and no humidity
sensor. The only difference between the Si705x is the temperature
accuracy of the reading, ranging from +/- 0.1 C in the Si7051 to +/- 1 C
in the Si7050.
This patch adds support for this family of sensors extending the
functionality of the existing si70xx driver. Following the style of
other modules, this implements a pseudomodule per supported chip, adding
si7050, si7051, si7053, si7054 and si7055 pseudomodules.
As a minor change this patch also implements the missing
si70xx_get_serial, si70xx_get_id and si70xx_get_revision functions that
were declared in the si70xx.h header but implemented as private
functions. The si70xx_get_id() may be relevant for the application to
know at run time exactly which version of the hardware is installed.
The updated test running with a Si7051 shows the following output, which
seems consistent with the room temperature conditions during the test.
```
make SI70XX_VARIANT=si7051 -C tests/driver_si70xx/ all flash
```
```
SI70XX temperature and humidity sensor test application
Initializing sensor...
[OK]
Found SI7051 sensor, revision 32
temperature: 24.71 C
temperature: 24.69 C
```
tests/driver_ds3231
drivers/ds3231: add alarm support with IRQ
drivers/ds3231: alarm support and documentation
drivers/ds3231: alarm interrupt with mutex
drivers/ds3231: alarm, _unlock function
fixup! drivers/ds3231: add alarm support
Some periph_rtt implementations do not provide `rtt_set_counter()`. This
adds `periph_rtt_set_counter` as feature to allow testing for its
availability. The feature is provided at CPU level if periph_rtt is
provided by the board for all CPUs implementing `rtt_set_counter()`.
The clock adjustment API only used a 16 bit integer for speed correction. This
is to course grained to allow compensating clock drifts at high accuracy.
Using a 32 bit integer instead would allow to fix for a drift of up to
about 1 nanosecond drift per each 5 seconds.
That ought to be enough for anyone! (*cough* *cough*)
- Use negative errno as error codes, rather than home-grown enums
- Update the home-grown enum with negative errno codes for backward
compatibility and mark it deprecated
- Update API doc to use negative errno codes
- Fix various style issues in Doxygen doc
- Use `@retval` to document specific return values instead of abusing
`@return` for this
- Align parameters to proper indent level
The driver uses the netdev interface. Due to the limited
capabilities of the transceiver (32 byte FIFO and no source address in the layer2 frame),
it relies on 6LowPAN compression and adds the source address to the frame for that.
