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Merge pull request #4 from adafruit/lps22
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Adding LPS22 support
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@ladyada
ladyada committed Jun 3, 2020
2 parents a533f8a + 419dd74 commit 824b044
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7 changes: 4 additions & 3 deletions README.rst
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Expand Up @@ -62,11 +62,12 @@ Usage Example
import adafruit_lps2x
i2c = busio.I2C(board.SCL, board.SDA)
lps = adafruit_lps2x.LPS25HW(i2c)
print("out of reset/init")
# uncomment and comment out the line after to use with the LPS22
# lps = adafruit_lps2x.LPS22(i2c)
lps = adafruit_lps2x.LPS25(i2c)
while True:
print("Pressure: %.2f hPa" % lps.pressure)
print("Temperature: %.2f C"% lps.temperature)
print("Temperature: %.2f C" % lps.temperature)
time.sleep(1)
Contributing
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207 changes: 154 additions & 53 deletions adafruit_lps2x.py
View file
Expand Up @@ -33,7 +33,7 @@
**Hardware:**
* `LPS25HB Breakout <https://www.adafruit.com/products/45XX>`_
* LPS25HB Breakout https://www.adafruit.com/products/4530
**Software and Dependencies:**
* Adafruit CircuitPython firmware for the supported boards:
Expand All @@ -44,20 +44,41 @@
"""
__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_LPS2X.git"
from time import sleep
from micropython import const
import adafruit_bus_device.i2c_device as i2cdevice
from adafruit_register.i2c_struct import ROUnaryStruct
from adafruit_register.i2c_bits import RWBits, ROBits
from adafruit_register.i2c_bit import RWBit

_WHO_AM_I = const(0x0F)
_CTRL_REG1 = const(0x20)
_CTRL_REG2 = const(0x21)
_PRESS_OUT_XL = const(0x28 | 0x80) # | 0x80 to set auto increment on multi-byte read
_TEMP_OUT_L = const(0x2B | 0x80) # | 0x80 to set auto increment on multi-byte read
# _LPS2X_I2CADDR_DEFAULT = 0x5D # LPS2X default i2c address
# _LPS2X_WHOAMI = 0x0F # Chip ID register
# _LPS2X_PRESS_OUT_XL =(# | 0x80) ///< | 0x80 to set auto increment on multi-byte read
# _LPS2X_TEMP_OUT_L = (0x2B # 0x80) ///< | 0x80 to set auto increment on
_LPS2X_WHO_AM_I = const(0x0F)
_LPS2X_PRESS_OUT_XL = const(
0x28 | 0x80
) # | 0x80 to set auto increment on multi-byte read
_LPS2X_TEMP_OUT_L = const(
0x2B | 0x80
) # | 0x80 to set auto increment on multi-byte read

_LPS25_CHIP_ID = 0xBD
_LPS25_DEFAULT_ADDRESS = 0x5D
_LPS25_CTRL_REG1 = const(0x20) # First control register. Includes BD & ODR
_LPS25_CTRL_REG2 = const(0x21) # Second control register. Includes SW Reset
# _LPS25_CTRL_REG3 = 0x22 # Third control register. Includes interrupt polarity
# _LPS25_CTRL_REG4 = 0x23 # Fourth control register. Includes DRDY INT control
# _LPS25_INTERRUPT_CFG = 0x24 # Interrupt control register
# _LPS25_THS_P_L_REG = 0xB0 # Pressure threshold value for int


# _LPS22_THS_P_L_REG = 0x0C # Pressure threshold value for int
_LPS22_CTRL_REG1 = 0x10 # First control register. Includes BD & ODR
_LPS22_CTRL_REG2 = 0x11 # Second control register. Includes SW Reset
# _LPS22_CTRL_REG3 = 0x12 # Third control register. Includes interrupt polarity

_LPS2X_DEFAULT_ADDRESS = 0x5D
_LPS25HB_CHIP_ID = 0xBD
_LPS22HB_CHIP_ID = 0xB1 # LPS22 default device id from WHOAMI


class CV:
Expand All @@ -84,64 +105,65 @@ def is_valid(cls, value):
class Rate(CV):
"""Options for ``data_rate``
+-----------------------+------------------------------------------------------------------+
| Rate | Description |
+-----------------------+------------------------------------------------------------------+
| ``Rate.ONE_SHOT`` | Setting `data_rate` to ``Rate.ONE_SHOT`` takes a single pressure |
| | and temperature measurement |
+-----------------------+------------------------------------------------------------------+
| ``Rate.RATE_1_HZ`` | 1 Hz |
+-----------------------+------------------------------------------------------------------+
| ``Rate.RATE_7_HZ`` | 7 Hz |
+-----------------------+------------------------------------------------------------------+
| ``Rate.RATE_12_5_HZ`` | 12.5 Hz |
+-----------------------+------------------------------------------------------------------+
| ``Rate.RATE_25_HZ`` | 25 Hz |
+-----------------------+------------------------------------------------------------------+
+-----------------------------+------------------------------------------------+
| Rate | Description |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP25_SHUTDOWN`` | Setting `data_rate` to ``Rate.LSP25_SHUTDOWN`` |
| | stops measurements from being taken |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP25_RATE_1_HZ`` | 1 Hz |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP25_RATE_7_HZ`` | 7 Hz |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP25_RATE_12_5_HZ`` | 12.5 Hz |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP25_RATE_25_HZ`` | 25 Hz |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP22_SHUTDOWN`` | Setting `data_rate` to ``Rate.LSP22_SHUTDOWN`` |
| | stops measurements from being taken |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP22_RATE_1_HZ`` | 1 Hz |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP22_RATE_10_HZ`` | 10 Hz |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP22_RATE_25_HZ`` | 25 Hz |
+-----------------------------+------------------------------------------------+
| ``Rate.LSP22_RATE_50_HZ`` | 50 Hz |
+-----------------------------+------------------------------------------------+
"""

pass # pylint: disable=unnecessary-pass


Rate.add_values(
(
("RATE_ONE_SHOT", 0, 0, None),
("RATE_1_HZ", 1, 1, None),
("RATE_7_HZ", 2, 7, None),
("RATE_12_5_HZ", 3, 12.5, None),
("RATE_25_HZ", 4, 25, None),
)
)


class LPS2X: # pylint: disable=too-many-instance-attributes
"""Library for the ST LPS2x family of pressure sensors
"""Base class ST LPS2x family of pressure sensors
:param ~busio.I2C i2c_bus: The I2C bus the LPS25HB is connected to.
:param ~busio.I2C i2c_bus: The I2C bus the sensor is connected to.
:param address: The I2C device address for the sensor. Default is ``0x5d`` but will accept
``0x5c`` when the ``SDO`` pin is connected to Ground.
"""

_chip_id = ROUnaryStruct(_WHO_AM_I, "<B")
_reset = RWBit(_CTRL_REG2, 2)
enabled = RWBit(_CTRL_REG1, 7)
"""Controls the power down state of the sensor. Setting to `False` will shut the sensor down"""
_data_rate = RWBits(3, _CTRL_REG1, 4)
_raw_temperature = ROUnaryStruct(_TEMP_OUT_L, "<h")
_raw_pressure = ROBits(24, _PRESS_OUT_XL, 0, 3)
_chip_id = ROUnaryStruct(_LPS2X_WHO_AM_I, "<B")
_raw_temperature = ROUnaryStruct(_LPS2X_TEMP_OUT_L, "<h")
_raw_pressure = ROBits(24, _LPS2X_PRESS_OUT_XL, 0, 3)

def __init__(self, i2c_bus, address=_LPS25_DEFAULT_ADDRESS):
def __init__(self, i2c_bus, address=_LPS2X_DEFAULT_ADDRESS, chip_id=None):
self.i2c_device = i2cdevice.I2CDevice(i2c_bus, address)
if not self._chip_id in [_LPS25_CHIP_ID]:
if not self._chip_id in [chip_id]:
raise RuntimeError(
"Failed to find LPS25HB! Found chip ID 0x%x" % self._chip_id
"Failed to find LPS2X! Found chip ID 0x%x" % self._chip_id
)

self.reset()
self.enabled = True
self.data_rate = Rate.RATE_25_HZ # pylint:disable=no-member
self.initialize()
sleep(0.010) # delay 10ms for first reading

def initialize(self): # pylint: disable=no-self-use
"""Configure the sensor with the default settings. For use after calling `reset()`"""
raise RuntimeError(
"LPS2X Base class cannot be instantiated directly. Use LPS22 or LPS25 instead"
) # override in subclass

def reset(self):
"""Reset the sensor, restoring all configuration registers to their defaults"""
Expand All @@ -162,16 +184,16 @@ def pressure(self):
@property
def temperature(self):
"""The current temperature measurement in degrees C"""

raw_temperature = self._raw_temperature
return (raw_temperature / 480) + 42.5
return (
raw_temperature / self._temp_scaling # pylint:disable=no-member
) + self._temp_offset # pylint:disable=no-member

@property
def data_rate(self):
"""The rate at which the sensor measures ``pressure`` and ``temperature``. ``data_rate``
shouldbe set to one of the values of ``adafruit_lps2x.DataRate``. Note that setting
``data_rate``to ``Rate.ONE_SHOT`` places the sensor into a low-power shutdown mode where
measurements toupdate ``pressure`` and ``temperature`` are only taken when
``take_measurement`` is called."""
shouldbe set to one of the values of ``adafruit_lps2x.Rate``."""
return self._data_rate

@data_rate.setter
Expand All @@ -180,3 +202,82 @@ def data_rate(self, value):
raise AttributeError("data_rate must be a `Rate`")

self._data_rate = value


class LPS25(LPS2X):
"""Library for the ST LPS25 pressure sensors
:param ~busio.I2C i2c_bus: The I2C bus the LPS25HB is connected to.
:param address: The I2C device address for the sensor. Default is ``0x5d`` but will accept
``0x5c`` when the ``SDO`` pin is connected to Ground.
"""

enabled = RWBit(_LPS25_CTRL_REG1, 7)
"""Controls the power down state of the sensor. Setting to `False` will shut the sensor down"""
_reset = RWBit(_LPS25_CTRL_REG2, 2)
_data_rate = RWBits(3, _LPS25_CTRL_REG1, 4)

def __init__(self, i2c_bus, address=_LPS2X_DEFAULT_ADDRESS):

Rate.add_values(
(
("LPS25_RATE_ONE_SHOT", 0, 0, None),
("LPS25_RATE_1_HZ", 1, 1, None),
("LPS25_RATE_7_HZ", 2, 7, None),
("LPS25_RATE_12_5_HZ", 3, 12.5, None),
("LPS25_RATE_25_HZ", 4, 25, None),
)
)
super().__init__(i2c_bus, address, chip_id=_LPS25HB_CHIP_ID)

self._temp_scaling = 480
self._temp_offset = 42.5
# self._inc_spi_flag = 0x40

def initialize(self):
"""Configure the sensor with the default settings. For use after calling `reset()`"""
self.enabled = True
self.data_rate = Rate.LPS25_RATE_25_HZ # pylint:disable=no-member

# void configureInterrupt(bool activelow, bool opendrain,
# bool pres_high = false, bool pres_low = false);


class LPS22(LPS2X):
"""Library for the ST LPS22 pressure sensors
:param ~busio.I2C i2c_bus: The I2C bus the LPS22HB is connected to.
:param address: The I2C device address for the sensor. Default is ``0x5d`` but will accept
``0x5c`` when the ``SDO`` pin is connected to Ground.
"""

_reset = RWBit(_LPS22_CTRL_REG2, 2)
_data_rate = RWBits(3, _LPS22_CTRL_REG1, 4)

def __init__(self, i2c_bus, address=_LPS2X_DEFAULT_ADDRESS):
# Only adding Class-appropriate rates
Rate.add_values(
(
("LPS22_RATE_ONE_SHOT", 0, 0, None),
("LPS22_RATE_1_HZ", 1, 1, None),
("LPS22_RATE_10_HZ", 2, 10, None),
("LPS22_RATE_25_HZ", 3, 25, None),
("LPS22_RATE_50_HZ", 4, 50, None),
("LPS22_RATE_75_HZ", 5, 75, None),
)
)

super().__init__(i2c_bus, address, chip_id=_LPS22HB_CHIP_ID)
self._temp_scaling = 100
self._temp_offset = 0

def initialize(self):
"""Configure the sensor with the default settings. For use after calling `reset()`"""
self.data_rate = Rate.LPS22_RATE_75_HZ # pylint:disable=no-member

# void configureInterrupt(bool activelow, bool opendrain, bool data_ready,
# bool pres_high = false, bool pres_low = false,
# bool fifo_full = false, bool fifo_watermark = false,
# bool fifo_overflow = false);
2 changes: 1 addition & 1 deletion docs/index.rst
View file
Expand Up @@ -27,7 +27,7 @@ Table of Contents
.. toctree::
:caption: Related Products

* `LPS25HW Breakout <https://www.adafruit.com/products/4258>`_
* LPS25HW Breakout <https://www.adafruit.com/products/4258>

.. toctree::
:caption: Other Links
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4 changes: 3 additions & 1 deletion examples/lps2x_simpletest.py
View file
Expand Up @@ -4,7 +4,9 @@
import adafruit_lps2x

i2c = busio.I2C(board.SCL, board.SDA)
lps = adafruit_lps2x.LPS2X(i2c)
# uncomment and comment out the line after to use with the LPS22
# lps = adafruit_lps2x.LPS22(i2c)
lps = adafruit_lps2x.LPS25(i2c)
while True:
print("Pressure: %.2f hPa" % lps.pressure)
print("Temperature: %.2f C" % lps.temperature)
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