# SPDX-FileCopyrightText: 2017 ladyada for Adafruit Industries
#
# SPDX-License-Identifier: MIT
"""
`adafruit_bme280.advanced`
=========================================================================================
CircuitPython driver from BME280 Temperature, Humidity and Barometric
Pressure sensor
* Author(s): ladyada, Jose David M.
Implementation Notes
--------------------
**Hardware:**
* `Adafruit BME280 Temperature, Humidity and Barometric Pressure sensor
<https://www.adafruit.com/product/2652>`_ (Product ID: 2652)
**Software and Dependencies:**
* Adafruit CircuitPython firmware for the supported boards:
https://circuitpython.org/downloads
* Adafruit's Bus Device library:
https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
"""
from micropython import const
from adafruit_bme280.basic import Adafruit_BME280
from adafruit_bme280.protocol import I2C_Impl, SPI_Impl
try:
import typing # pylint: disable=unused-import
from busio import I2C, SPI
from digitalio import DigitalInOut
except ImportError:
pass
__version__ = "0.0.0+auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_BME280.git"
# I2C ADDRESS/BITS/SETTINGS
# -----------------------------------------------------------------------
_BME280_ADDRESS = const(0x77)
_BME280_CHIPID = const(0x60)
_BME280_REGISTER_CHIPID = const(0xD0)
_BME280_REGISTER_DIG_T1 = const(0x88)
_BME280_REGISTER_DIG_H1 = const(0xA1)
_BME280_REGISTER_DIG_H2 = const(0xE1)
_BME280_REGISTER_DIG_H3 = const(0xE3)
_BME280_REGISTER_DIG_H4 = const(0xE4)
_BME280_REGISTER_DIG_H5 = const(0xE5)
_BME280_REGISTER_DIG_H6 = const(0xE7)
_BME280_REGISTER_SOFTRESET = const(0xE0)
_BME280_REGISTER_CTRL_HUM = const(0xF2)
_BME280_REGISTER_STATUS = const(0xF3)
_BME280_REGISTER_CTRL_MEAS = const(0xF4)
_BME280_REGISTER_CONFIG = const(0xF5)
_BME280_REGISTER_PRESSUREDATA = const(0xF7)
_BME280_REGISTER_TEMPDATA = const(0xFA)
_BME280_REGISTER_HUMIDDATA = const(0xFD)
_BME280_HUMIDITY_MIN = const(0)
_BME280_HUMIDITY_MAX = const(100)
"""iir_filter values"""
IIR_FILTER_DISABLE = const(0)
IIR_FILTER_X2 = const(0x01)
IIR_FILTER_X4 = const(0x02)
IIR_FILTER_X8 = const(0x03)
IIR_FILTER_X16 = const(0x04)
_BME280_IIR_FILTERS = (
IIR_FILTER_DISABLE,
IIR_FILTER_X2,
IIR_FILTER_X4,
IIR_FILTER_X8,
IIR_FILTER_X16,
)
"""overscan values for temperature, pressure, and humidity"""
OVERSCAN_DISABLE = const(0x00)
OVERSCAN_X1 = const(0x01)
OVERSCAN_X2 = const(0x02)
OVERSCAN_X4 = const(0x03)
OVERSCAN_X8 = const(0x04)
OVERSCAN_X16 = const(0x05)
_BME280_OVERSCANS = {
OVERSCAN_DISABLE: 0,
OVERSCAN_X1: 1,
OVERSCAN_X2: 2,
OVERSCAN_X4: 4,
OVERSCAN_X8: 8,
OVERSCAN_X16: 16,
}
"""mode values"""
MODE_SLEEP = const(0x00)
MODE_FORCE = const(0x01)
MODE_NORMAL = const(0x03)
_BME280_MODES = (MODE_SLEEP, MODE_FORCE, MODE_NORMAL)
"""
standby timeconstant values
TC_X[_Y] where X=milliseconds and Y=tenths of a millisecond
"""
STANDBY_TC_0_5 = const(0x00) # 0.5ms
STANDBY_TC_10 = const(0x06) # 10ms
STANDBY_TC_20 = const(0x07) # 20ms
STANDBY_TC_62_5 = const(0x01) # 62.5ms
STANDBY_TC_125 = const(0x02) # 125ms
STANDBY_TC_250 = const(0x03) # 250ms
STANDBY_TC_500 = const(0x04) # 500ms
STANDBY_TC_1000 = const(0x05) # 1000ms
_BME280_STANDBY_TCS = (
STANDBY_TC_0_5,
STANDBY_TC_10,
STANDBY_TC_20,
STANDBY_TC_62_5,
STANDBY_TC_125,
STANDBY_TC_250,
STANDBY_TC_500,
STANDBY_TC_1000,
)
# pylint: disable=abstract-method
[docs]
class Adafruit_BME280_Advanced(Adafruit_BME280):
"""Driver from BME280 Temperature, Humidity and Barometric Pressure sensor
.. note::
The operational range of the BMP280 is 300-1100 hPa.
Pressure measurements outside this range may not be as accurate.
"""
# pylint: disable=too-many-instance-attributes
def __init__(self, proxy: typing.Union[I2C_Impl, SPI_Impl]) -> None:
"""Check the BME280 was found, read the coefficients and enable the sensor"""
self._overscan_humidity = OVERSCAN_X1
self._overscan_temperature = OVERSCAN_X1
self._overscan_pressure = OVERSCAN_X16
self._mode = MODE_SLEEP
self._t_standby = STANDBY_TC_125
super().__init__(proxy)
@property
def standby_period(self) -> int:
"""
Control the inactive period when in Normal mode
Allowed standby periods are the constants STANDBY_TC_*
"""
return self._t_standby
@standby_period.setter
def standby_period(self, value: int) -> None:
if not value in _BME280_STANDBY_TCS:
raise ValueError("Standby Period '%s' not supported" % (value))
if self._t_standby == value:
return
self._t_standby = value
self._write_config()
@property
def overscan_humidity(self) -> int:
"""
Humidity Oversampling
Allowed values are the constants OVERSCAN_*
"""
return self._overscan_humidity
@overscan_humidity.setter
def overscan_humidity(self, value: int) -> None:
if not value in _BME280_OVERSCANS:
raise ValueError("Overscan value '%s' not supported" % (value))
self._overscan_humidity = value
self._write_ctrl_meas()
@property
def overscan_temperature(self) -> int:
"""
Temperature Oversampling
Allowed values are the constants OVERSCAN_*
"""
return self._overscan_temperature
@overscan_temperature.setter
def overscan_temperature(self, value: int) -> None:
if not value in _BME280_OVERSCANS:
raise ValueError("Overscan value '%s' not supported" % (value))
self._overscan_temperature = value
self._write_ctrl_meas()
@property
def overscan_pressure(self) -> int:
"""
Pressure Oversampling
Allowed values are the constants OVERSCAN_*
"""
return self._overscan_pressure
@overscan_pressure.setter
def overscan_pressure(self, value: int) -> None:
if not value in _BME280_OVERSCANS:
raise ValueError("Overscan value '%s' not supported" % (value))
self._overscan_pressure = value
self._write_ctrl_meas()
@property
def iir_filter(self) -> int:
"""
Controls the time constant of the IIR filter
Allowed values are the constants IIR_FILTER_*
"""
return self._iir_filter
@iir_filter.setter
def iir_filter(self, value: int) -> None:
if not value in _BME280_IIR_FILTERS:
raise ValueError("IIR Filter '%s' not supported" % (value))
self._iir_filter = value
self._write_config()
@property
def _config(self) -> int:
"""Value to be written to the device's config register"""
config = 0
if self.mode == MODE_NORMAL:
config += self._t_standby << 5
if self._iir_filter:
config += self._iir_filter << 2
return config
@property
def _ctrl_meas(self) -> int:
"""Value to be written to the device's ctrl_meas register"""
ctrl_meas = self.overscan_temperature << 5
ctrl_meas += self.overscan_pressure << 2
ctrl_meas += self.mode
return ctrl_meas
@property
def measurement_time_typical(self) -> float:
"""Typical time in milliseconds required to complete a measurement in normal mode"""
meas_time_ms = 1.0
if self.overscan_temperature != OVERSCAN_DISABLE:
meas_time_ms += 2 * _BME280_OVERSCANS.get(self.overscan_temperature)
if self.overscan_pressure != OVERSCAN_DISABLE:
meas_time_ms += 2 * _BME280_OVERSCANS.get(self.overscan_pressure) + 0.5
if self.overscan_humidity != OVERSCAN_DISABLE:
meas_time_ms += 2 * _BME280_OVERSCANS.get(self.overscan_humidity) + 0.5
return meas_time_ms
@property
def measurement_time_max(self) -> float:
"""Maximum time in milliseconds required to complete a measurement in normal mode"""
meas_time_ms = 1.25
if self.overscan_temperature != OVERSCAN_DISABLE:
meas_time_ms += 2.3 * _BME280_OVERSCANS.get(self.overscan_temperature)
if self.overscan_pressure != OVERSCAN_DISABLE:
meas_time_ms += 2.3 * _BME280_OVERSCANS.get(self.overscan_pressure) + 0.575
if self.overscan_humidity != OVERSCAN_DISABLE:
meas_time_ms += 2.3 * _BME280_OVERSCANS.get(self.overscan_humidity) + 0.575
return meas_time_ms
[docs]
class Adafruit_BME280_I2C(Adafruit_BME280_Advanced):
"""Driver for BME280 connected over I2C
:param ~busio.I2C i2c: The I2C bus the BME280 is connected to.
:param int address: I2C device address. Defaults to :const:`0x77`.
but another address can be passed in as an argument
.. note::
The operational range of the BMP280 is 300-1100 hPa.
Pressure measurements outside this range may not be as accurate.
**Quickstart: Importing and using the BME280**
Here is an example of using the :class:`Adafruit_BME280_I2C`.
First you will need to import the libraries to use the sensor
.. code-block:: python
import board
import adafruit_bme280.advanced as adafruit_bme280
Once this is done you can define your `board.I2C` object and define your sensor object
.. code-block:: python
i2c = board.I2C() # uses board.SCL and board.SDA
bme280 = adafruit_bme280.Adafruit_BME280_I2C(i2c)
You need to setup the pressure at sea level
.. code-block:: python
bme280.sea_level_pressure = 1013.25
Now you have access to the :attr:`temperature`, :attr:`relative_humidity`
:attr:`pressure` and :attr:`altitude` attributes
.. code-block:: python
temperature = bme280.temperature
relative_humidity = bme280.relative_humidity
pressure = bme280.pressure
altitude = bme280.altitude
"""
def __init__(self, i2c: I2C, address: int = _BME280_ADDRESS) -> None:
super().__init__(I2C_Impl(i2c, address))
[docs]
class Adafruit_BME280_SPI(Adafruit_BME280_Advanced):
"""Driver for BME280 connected over SPI
:param ~busio.SPI spi: SPI device
:param ~digitalio.DigitalInOut cs: Chip Select
:param int baudrate: Clock rate, default is 100000. Can be changed with :meth:`baudrate`
.. note::
The operational range of the BMP280 is 300-1100 hPa.
Pressure measurements outside this range may not be as accurate.
**Quickstart: Importing and using the BME280**
Here is an example of using the :class:`Adafruit_BME280_SPI` class.
First you will need to import the libraries to use the sensor
.. code-block:: python
import board
from digitalio import DigitalInOut
import adafruit_bme280.advanced as adafruit_bme280
Once this is done you can define your `board.SPI` object and define your sensor object
.. code-block:: python
cs = digitalio.DigitalInOut(board.D10)
spi = board.SPI()
bme280 = adafruit_bme280.Adafruit_BME280_SPI(spi, cs)
You need to setup the pressure at sea level
.. code-block:: python
bme280.sea_level_pressure = 1013.25
Now you have access to the :attr:`temperature`, :attr:`relative_humidity`
:attr:`pressure` and :attr:`altitude` attributes
.. code-block:: python
temperature = bme280.temperature
relative_humidity = bme280.relative_humidity
pressure = bme280.pressure
altitude = bme280.altitude
"""
def __init__(self, spi: SPI, cs: DigitalInOut, baudrate: int = 100000) -> None:
super().__init__(SPI_Impl(spi, cs, baudrate))