.. module:: bmp180

*************
BMP180 Module
*************

This module contains the driver for BOSCH BMP180 Digital Barometric Pressure Sensor. The ultra-low power, low voltage electronics of the BMP180 is optimized for use in mobile devices and the I2C interface allows for easy
system integration with a microcontroller. The BMP180 is based on piezo-resistive technology for EMC robustness, high accuracy and linearity as
well as long term stability (`datasheet <https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf>`_).
    
.. class:: BMP180(i2cdrv, addr=0x77, clk=100000)

    Creates an intance of a new BMP180.

    :param i2cdrv: I2C Bus used '( I2C0, ... )'
    :param addr: Slave address, default 0x77
    :param clk: Clock speed, default 100kHz

    Example: ::

        from bosch.bmp180 import bmp180

        ...

        bmp = bmp180.BMP180(I2C0)
        bmp.start()
        bmp.init()
        temp, pres = bmp.get_temp_pres()

    
.. method:: init(oss=0)

        Initialize the BMP180 calibrating the sensor and setting the oss value.

        :param oss: OverSampling Setting value (from 0 to 4), default 0

        
.. method:: set_over_sampling_setting(oss)

        Sets the OverSampling Setting value of the BMP180.

        :param oss: OverSampling Setting value (from 0 to 4 allowed)

.. note:: The OverSampling Setting parameter selects different operating modes according to give the possibility for findind the optimum compromise between power consumption, speed, and resolution; in the table below allowed values are reported with related operating modes.

========= ===================== ============ =============== ======================
OSS param     Operating Mode    N of samples Conversion time Avg Current 1 sample/s
========= ===================== ============ =============== ======================
    0        Ultra Low Power         1           4.5 ms                3 uA
    1           Standard             2           7.5 ms                5 uA
    2        High Resolution         4          13.5 ms                7 uA
    3     Ultra High Resolution      8          25.5 ms               12 uA
========= ===================== ============ =============== ======================
                     
        
.. method:: get_raw_temp()

        Retrieves the current temperature data from the sensor as raw value.

        Returns raw_t

        
.. method:: get_raw_pres()

        Retrieves the current pressure data from the sensor as raw value; according to the OverSampling Setting value this measure can be
        faster but less accurate or more precise but slower. (see :func:`set_over_sampling_setting()`)

        Returns raw_p

        
.. method:: get_temp()

        Retrieves the current temperature data from the sensor as calibrate value in °C.

        Returns temp

        
.. method:: get_pres()

        Retrieves the current pressure data from the sensor as calibrate value in Pa; according to the OverSampling Setting value this measure can be
        faster but less accurate or more precise but slower. (see :func:`set_over_sampling_setting()`)

        Returns pres

        
.. method:: get_temp_pres()

        Retrieves the current temperature (in °C) and pressure (in Pa) data from the sensor as calibrate values in one call.

        Returns temp

        
.. method:: get_altitude()

        Calculates, from measured pressure, the current altitude data as value in meters.

        Returns altitude

        
.. method:: get_sea_level_pres()

        Calculates, from measured pressure, the pressure (in Pa) at sea level when given a known altitude in meters.

        Returns p0 (pressure at sea level)