In a heavy EMI environment, reading the current config from the MAX31865 can
fail, such as switching from a 4-wire sensor to a 3-wire sensor. This causes
the temperature value to be off wildly, but still technically valid, so it
doesn't get reported as a sensor failure.
Since we know what configuration we want, rather than send it to the MAX31865
on setup and ask for it over and over (propagating any error as we write it
back), instead store the base configuration and work from that to change modes.
This not only avoids propagating any error, it also saves a lot of unnecessary
reads from the MAX31865.
* Add MAX31865 sensor support, fix MAX31855 sensor.
# MAX31865
Added support for the MAX31865 RTD-to-Digital Converter to measure PT100 and
similar RTDs. Verified with an Adafruit unit (product ID: 3328) and a PT100
probe.
# MAX31855
This was setup for incorrect SPI clock polarity and phase, and would return bad
data due to a race condition measuring on the wrong edge (verified with Saleae
Logic scope). Selecting the correct configuration fixes that problem.
Re-wrote the decode off the datasheet to handle error states better (sends NaN
as an update on failure to read temperature, which shows the value as Unknown
in Home Assistant).
Added the *optional* ability to monitor the internal high-precision temperature
sensor, which can be nice in some applications.
* Tests for MAX31855/MAX38165.
* Update style to match project rules.
Also fix CONF_REFERENCE_RESISTANCE and CONF_REFERENCE_TEMPERATURE being defined
multiple places. Missed this when I added them to const.py.
* Update style to match project rules.
Pylint line limit 101/100 ("missed it by that much").
Also apparently I can't read and patched the wrong line in max31855.cpp.
* Minor string/style cleanup.
There was a copy-paste leftover in max31855.cpp and max31865/sensor.py had
unnecessary whitespace.
* Improve MAX31865 fault detection and logging.
Log levels are more in-line with the documented descriptions.
Fault detection code is improved. A transient fault between reads is still
reported, but now only faults *during* a read cause the sensor to fail and
return NAN ("unknown" in Home Assistant).
* Update style to match project rules.
I just now realized the .clang-format and pylintrc files are included. D'oh!
* MAX31855 & MAX31865 code style alignment.
@OttoWinter caught some style mismatches, updated to match project better.
* Fix a lost '\' in max31865/sensor.py.
Otto Winter