.. module:: FBM320

**************
FBM320 Module
**************

.. _datasheet: http://www.fmti.com.tw/fmti689/program_download/good/201702101732113548.pdf

This module contains the Zerynth driver for FBM320 digital barometer. 
The FBM320 is a digital pressure sensor which consists of a MEMS piezoresistive pressure sensor and a signal
conditioning ASIC. The ASIC include a 24bits sigma-delta ADC, OTP memory for calibration data,
and serial interface circuits. The FBM320 features I2C and SPI digital interfaces, the present library enables I2C only.
    
===============
 FBM320 class
===============

.. class:: FBM320(drvname, addr=0x6D, clk=400000)

    Creates an intance of the FBM320 class.

    :param drvname: I2C Bus used '( I2C0, ... )'
    :param addr: Slave address, default 0x6D.
                 If SDO pin is pulled low, I2C address is 6C.
                 If SDO pin is pulled high, I2C address is 6D.
    :param clk: Clock speed, default 400kHz
    
    Barometer values can be easily obtained from the sensor: ::

        from formosa.fbm320 import fbm320

        ...

        fbm = fbm320.FBM320(I2C0)

        temp, press, altitude = fbm.get_values()

    
.. method:: set_osr(osr)

    :param osr: is the oversampling rate to set. Values accepted: 1024, 2048, 4096 or 8192.
    
    Set oversampling rate.
    
    
.. method:: get_temp()
    
    Return the temperature in degrees Celsius.
    
    
.. method:: get_press()
    
    Return the pressure in hPa.
    
    
.. method:: get_altitude(pressure)
    
    :param pressure: pressure value in hPa.

    Return the altitude in metres.
    
    
.. method:: get_values()
    
    Return the temperature (°C), pressure (hPa) and altitude (m) in a list [temperature, pressure, altitude].