samples: sensor: bme280: add README.rst

.. _bme280:

BME280 Humidity and Pressure Sensor

###################################

Overview

********

This sample application periodically reads temperature, pressure and humidity data from

the first available device that implements SENSOR_CHAN_AMBIENT_TEMP, SENSOR_CHAN_PRESS,

and SENSOR_CHAN_HUMIDITY. This sample checks the sensor in polling mode (without

interrupt trigger).

Building and Running

********************

This sample application uses an BME280 sensor connected to an Arduino 101 board via I2C.

Connect the sensor pins according to the connection diagram given in the `bme280 datasheet`_

at page 38.

There are two processor cores (x86 and ARC) on the Arduino 101. You will need to

flash both this sample's code on the ARC core (using the ``arduino101_sss`` board target),

and stub code on the x86 core (using the ``arduino_101`` board target), as shown below.

.. zephyr-app-commands::

   :zephyr-app: samples/sensors/bme280

   :board: arduino_101_sss

   :goals: flash

   :compact:

.. zephyr-app-commands::

   :zephyr-app: tests/booting/stub

   :board: arduino_101

   :goals: flash

   :compact:

Sample Output

=============

To check output of this sample , any serial console program can be used.

This example uses ``picocom`` on the serial port ``/dev/ttyUSB0``:

.. code-block:: console

        $ sudo picocom -D /dev/ttyUSB0

.. code-block:: console

        temp: 27.950000; press: 100.571027; humidity: 61.014648

        temp: 27.940000; press: 100.570269; humidity: 61.012695

        temp: 27.950000; press: 100.570695; humidity: 61.002929

.. _bme280 datasheet: https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280-DS002.pdf

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