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Removing pressure limitations, to unify behavior to BME280 #30

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Merged
merged 2 commits into from
Apr 23, 2021
Merged

Removing pressure limitations, to unify behavior to BME280 #30

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0341f08
Removing pressure limitations, to unify behavior to BME280
jposada202020 Apr 23, 2021
dfc6011
Adding pressure capabilities notes
jposada202020 Apr 23, 2021
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24 changes: 13 additions & 11 deletions adafruit_bmp280.py
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Original file line number Diff line number Diff line change
Expand Up @@ -35,9 +35,6 @@
_REGISTER_PRESSUREDATA = const(0xF7)
_REGISTER_TEMPDATA = const(0xFA)

_BMP280_PRESSURE_MIN_HPA = const(300)
_BMP280_PRESSURE_MAX_HPA = const(1100)


"""iir_filter values"""
IIR_FILTER_DISABLE = const(0)
Expand Down Expand Up @@ -105,7 +102,13 @@
class Adafruit_BMP280: # pylint: disable=invalid-name
"""Base BMP280 object. Use `Adafruit_BMP280_I2C` or `Adafruit_BMP280_SPI` instead of this. This
checks the BMP280 was found, reads the coefficients and enables the sensor for continuous
reads"""
reads

.. note::
The operational range of the BMP280 is 300-1100 hPa.
Pressure measurements outside this range may not be as accurate.

"""

def __init__(self):
# Check device ID.
Expand Down Expand Up @@ -158,7 +161,7 @@ def _reset(self):
def _write_ctrl_meas(self):
"""
Write the values to the ctrl_meas register in the device
ctrl_meas sets the pressure and temperature data acquistion options
ctrl_meas sets the pressure and temperature data acquisition options
"""
self._write_register_byte(_REGISTER_CTRL_MEAS, self._ctrl_meas)

Expand Down Expand Up @@ -320,18 +323,17 @@ def pressure(self):
var3 = self._pressure_calib[2] * var1 * var1 / 524288.0
var1 = (var3 + self._pressure_calib[1] * var1) / 524288.0
var1 = (1.0 + var1 / 32768.0) * self._pressure_calib[0]
if not var1:
return _BMP280_PRESSURE_MIN_HPA
if not var1: # avoid exception caused by division by zero
raise ArithmeticError(
"Invalid result possibly related to error while reading the calibration registers"
)
pressure = 1048576.0 - adc
pressure = ((pressure - var2 / 4096.0) * 6250.0) / var1
var1 = self._pressure_calib[8] * pressure * pressure / 2147483648.0
var2 = pressure * self._pressure_calib[7] / 32768.0
pressure = pressure + (var1 + var2 + self._pressure_calib[6]) / 16.0
pressure /= 100
if pressure < _BMP280_PRESSURE_MIN_HPA:
return _BMP280_PRESSURE_MIN_HPA
if pressure > _BMP280_PRESSURE_MAX_HPA:
return _BMP280_PRESSURE_MAX_HPA

return pressure

@property
Expand Down