adafruit_lps35hw

A driver for the ST LPS35HW water resistant MEMS pressure sensor

  • Author(s): Bryan Siepert

Implementation Notes

Hardware:

Software and Dependencies:
class adafruit_lps35hw.DataRate

Options for data_rate

DataRate

Time

DataRate.ONE_SHOT

One shot mode

DataRate.RATE_1_HZ

1 hz

DataRate.RATE_10_HZ

10 hz (Default)

DataRate.RATE_25_HZ

25 hz

DataRate.RATE_50_HZ

50 hz

DataRate.RATE_75_HZ

75 hz
class adafruit_lps35hw.LPS35HW(i2c_bus: I2C, address: int = 93)

Driver for the ST LPS35HW MEMS pressure sensor

Parameters:

  • i2c_bus (I2C) – The I2C bus the LPS35HW is connected to.

  • address (int) – The I2C device address for the sensor. Default is 0x5d but will accept 0x5c when the SDO pin is connected to Ground.

Quickstart: Importing and using the LPS35HW

Here is an example of using the LPS35HW class. First you will need to import the libraries to use the sensor

import board
import adafruit_lps35hw

Once this is done you can define your board.I2C object and define your sensor object

i2c = board.I2C()   # uses board.SCL and board.SDA
lps = adafruit_lps35hw.LPS35HW(i2c)

Now you have access to the temperature and pressure attributes. Temperature is in Celsius and Pressure is in hPa.

temperature = lps.temperature
pressure = lps.pressure
data_rate = 3
The rate at which the sensor measures pressure and temperature.

data_rate should be set to one of the values of adafruit_lps35hw.DataRate().

Note

Setting data_rate to DataRate.ONE_SHOT places the sensor into a low-power shutdown mode where measurements to update pressure and temperature are only taken when take_measurement() is called.

property high_threshold_enabled: bool

Set to True or False to enable or disable the high pressure threshold

property high_threshold_exceeded: bool

Returns True if the pressure high threshold has been exceeded. Must be enabled by setting high_threshold_enabled to True and setting a pressure_threshold.

low_pass_enabled

True if the low pass filter is enabled. Setting to True will reduce the sensor bandwidth from \(data_rate/2\) to \(data_rate/9\), filtering out high-frequency noise.

property low_threshold_enabled: bool

Set to True or False to enable or disable the low pressure threshold.

Note

The low pressure threshold only works in relative mode

property low_threshold_exceeded: bool

Returns True if the pressure low threshold has been exceeded. Must be enabled by setting high_threshold_enabled to True and setting a pressure_threshold.

property pressure: float

The current pressure measurement in hPa

property pressure_threshold: float

The high pressure threshold. Use high_threshold_enabled or high_threshold_enabled to use it

reset() → None

Reset the sensor, restoring all configuration registers to their defaults

reset_pressure() → None

Reset pressure to be reported as the measured absolute value

take_measurement() → None

Update the value of pressure and temperature by taking a single measurement. Only meaningful if data_rate is set to ONE_SHOT

property temperature: float

The current temperature measurement in degrees Celsius

zero_pressure() → None

Set the current pressure as zero and report the pressure relative to it