Enabling an Off-Board Sensor in an Existing Application
-------------------------------------------------------

This tutorial shows you how to enable an existing application to run on
a device with an off-board sensor device connected to it. It allows you
to quickly bring up and run a Mynewt application on a device to view
sensor data from a sensor device.

We use the **sensors\_test** application running on an nRF52-DK board to
communicate, via the I2C interface, with the :doc:`Adafruit
BNO055 <https://learn.adafruit.com/adafruit-bno055-absolute-orientation-sensor/overview>`
sensor. The sensors\_test application is a sample application that
demonstrates all the features of the Mynewt sensor framework. The
application includes the sensor framework ``sensor`` shell command that
allows you to view the sensors and sensor data managed by the sensor
framework, and the ``bno055`` shell command that allows you to control
and query the BNO055 device and to view the sensor data.

This tutorial shows you how to:

-  Create and build the application and bootloader targets.
-  Connect a BNO055 sensor device to an nRF52-DK board.
-  Run ``sensor`` and ``bno055`` shell commands to view the sensor data
   and control the bno055 sensor device.

.. contents::
  :local:
  :depth: 2

Prerequisites
~~~~~~~~~~~~~

-  Meet the prerequisites listed in :doc:`Sensor
   Tutorials <sensors>`
-  Have a Nordic nRF52-DK board.
-  Have an `Adafruit
   BNO055 <https://learn.adafruit.com/adafruit-bno055-absolute-orientation-sensor/overview>`__
   sensor.
-  Have a :doc:`serial port setup <../../get_started/serial_access>`
-  Install the `Segger JLINK software and documentation
   pack <https://www.segger.com/jlink-software.html>`__.

Description of the Packages Needed for the Sample Application
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The sensors\_test application includes all the packages, and sets the
syscfg settings to values, that are required to enable the full set of
sensor framework features. This tutorial uses a subset of the
sensors\_test application functionality because the objective of the
tutorial is to show you how to quickly bring up the sensors\_test
application and use the ``sensor`` and ``bno055`` shell commands to view
the sensor data from the BNO055 sensor. The instructions in this
tutorial show the syscfg settings that must be enabled in the
sensors\_test application to demonstrate the examples shown. The
instructions do not explicity exclude the packages or change the syscfg
setting values to disable the functionality that is not used in the
sensors\_test application.

For your reference, we describe the packages and the setting values that
enable the application functionality that this tutorial demonstrates:

-  **hw/sensor**: The sensor framework package. This package defines the
   ``SENSOR_CLI`` setting that specifies whether the ``sensor`` shell
   command is enabled. This setting is enabled by default.

-  **hw/sensor/creator**: The sensor creator package. This package
   supports off-board sensor devices. This package creates the os
   devices in the kernel for the sensors and configures the sensor
   devices with default values. It defines a syscfg setting for each
   sensor device and uses the naming convention ``<SENSORNAME>_OFB``.
   For example, the syscfg setting for the BNO055 sensor is
   ``BNO055_OFB``. The ``<SENSORNAME>_OFB`` setting specifies whether
   the sensor named SENSORNAME is enabled. The setting is disabled by
   default. This package includes the sensor device driver package
   ``hw/drivers/sensors/<sensorname>`` and creates and configures a
   sensor named SENSORNAME when the ``SENSORNAME_OFB`` setting is
   enabled by the application.
-  **hw/drivers/sensors/bno055**: The driver package for the BNO055
   sensor. The creator package adds this package as a package dependency
   when the ``BNO055_OFB`` setting is enabled. The driver package
   defines the ``BNO055_CLI`` setting that specfies whether the
   ``bno055`` shell command is enabled. This setting is disabled by
   default and is enabled by the application. The package also exports
   the ``bno055_shell_init()`` function that an application calls to
   initialize the driver shell support.

   **Note:** All sensor driver packages that support a sensor shell
   command define a syscfg setting to specify whether the shell command
   is enabled. They also export a shell initialization function that an
   application must call. The naming convention is ``<SENSORNAME>_CLI``
   for the syscfg setting and ``<sensorname>_shell_init()`` for the
   initialization function.

-  **sys/shell** and **sys/console/full**: The shell and console
   packages for shell support over the console. The ``SHELL_TASK``
   setting needs to be set to enable the shell support in the package.
   The sensors\_test application enables this setting by default.

Step 1: Creating the Application Target
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In this step, you create a target for the sensors\_test application that enables the BNO055
off-board sensor.

To add the BNO055 sensor support, you create the application target with
the following syscfg settings enabled:

-  ``I2C_0``: Enables the I2C interface 0 in the nRF52 BSP HAL setting.
-  | ``BNO055_OFB``: Enables support for the BNO055 sensor in the sensor
     creator package (``hw/sensor/creator``).
   | When this setting is enabled, the creator package performs the
     following:

   -  Includes the BNO055 driver package (``hw/drivers/sensors/bno055``)
      as a package dependency.
   -  Creates an os device for the sensor in the Mynewt kernel.
   -  Configures the sensor device with default values.

-  ``BNO055_CLI``: Enables the ``bno055`` shell command in the bno055
   device driver package. The sensors\_test application also uses this
   setting to conditionally include the call to the
   ``bno055_shell_init()`` function to initialize the shell support in
   the driver.

**Note:** This tutorial uses the ``sensor`` and the ``bno055`` shell
commands. The ``SENSOR_CLI`` setting, that specifies whether the
``sensor`` shell command is enabled, is enabled by default.

1. Run the ``newt target create`` command, from your project base
directory, to create the target. We name the target
``nrf52_bno055_test``:

.. code-block:: console


    $ newt target create nrf52_bno055_test
    Target targets/nrf52_bno055_test successfully created
    $

2. Run the ``newt target set`` command to set the app, bsp, and
build\_profile variables for the target:

.. code-block:: console


    $ newt target set nrf52_bno055_test app=@apache-mynewt-core/apps/sensors_test bsp=@apache-mynewt-core/hw/bsp/nrf52dk build_profile=debug
    Target targets/nrf52_bno055_test successfully set target.app to @apache-mynewt-core/apps/sensors_test
    Target targets/nrf52_bno055_test successfully set target.bsp to @apache-mynewt-core/hw/bsp/nrf52dk
    Target targets/nrf52_bno055_test successfully set target.build_profile to debug

    $

3. Run the ``newt target set`` command to enable the ``I2C_0``,
``BNO055_OFB``, and ``BBNO055_CLI`` syscfg settings:

.. code-block:: console


    $ newt target set nrf52_bno055_test syscfg=BNO055_OFB=1:I2C_0=1:BNO055_CLI=1
    Target targets/nrf52_bno055_test successfully set target.syscfg to BNO055_OFB=1:I2C_0=1:BNO055_CLI=1
    $

Step 2: Creating the Bootloader Target
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Run the following ``newt target`` commands, from your project directory, to create a
bootloader target. We name the target ``nrf52_boot``:

.. code-block:: console


    $ newt target create nrf52_boot
    Target targets/nrf52_boot successfully created
    $ newt target set nrf52_boot app=@mcuboot/boot/mynewt bsp=@apache-mynewt-core/hw/bsp/nrf52dk  build_profile=optimized
    Target targets/nrf52_boot successfully set target.app to @mcuboot/boot/mynewt
    Target targets/nrf52_boot successfully set target.bsp to @apache-mynewt-core/hw/bsp/nrf52dk
    Target targets/nrf52_boot successfully set target.build_profile to optimized
    $

Step 3: Building the Bootloader and Application Image
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Run the ``newt build nrf52_boot`` command to build the bootloader:

.. code-block:: console

    $ newt build nrf52_boot
    Building target targets/nrf52_boot
    Compiling repos/mcuboot/boot/bootutil/src/image_ec.c
    Compiling repos/mcuboot/boot/bootutil/src/image_rsa.c
    Compiling repos/mcuboot/boot/bootutil/src/image_ec256.c
    Compiling repos/mcuboot/boot/bootutil/src/loader.c
    Compiling repos/mcuboot/boot/bootutil/src/bootutil_misc.c
    Compiling repos/mcuboot/boot/mynewt/src/main.c

       ...

    Archiving sys_mfg.a
    Archiving sys_sysinit.a
    Archiving util_mem.a
    Linking ~/dev/myproj/bin/targets/nrf52_boot/app/boot/mynewt/mynewt.elf
    Target successfully built: targets/nrf52_boot

2. Run the ``newt build nrf52_bno055_test`` command to build the
sensors\_test application:

.. code-block:: console

    $ newt build nrf52_bno055_test
    Building target targets/nrf52_bno055_test
    Compiling repos/mcuboot/boot/bootutil/src/image_ec.c
    Compiling repos/mcuboot/boot/bootutil/src/image_rsa.c
    Compiling repos/mcuboot/boot/bootutil/src/image_ec256.c
    Compiling repos/mcuboot/boot/bootutil/src/image_validate.c
    Compiling repos/mcuboot/boot/bootutil/src/bootutil_misc.c
    Compiling repos/apache-mynewt-core/apps/sensors_test/src/misc.c
    Compiling repos/apache-mynewt-core/apps/sensors_test/src/gatt_svr.c
    Compiling repos/apache-mynewt-core/apps/sensors_test/src/main.c

       ...

    Compiling repos/apache-mynewt-core/hw/drivers/sensors/bno055/src/bno055.c
    Compiling repos/apache-mynewt-core/hw/drivers/sensors/bno055/src/bno055_shell.c

       ...

    Compiling repos/apache-mynewt-core/hw/sensor/src/sensor.c
    Compiling repos/apache-mynewt-core/hw/sensor/src/sensor_oic.c
    Compiling repos/apache-mynewt-core/hw/sensor/src/sensor_shell.c
    Compiling repos/apache-mynewt-core/hw/sensor/creator/src/sensor_creator.c

        ...

    Archiving util_mem.a
    Archiving util_parse.a
    Linking ~/dev/myproj/bin/targets/nrf52_bno055_test/app/apps/sensors_test/sensors_test.elf
    Target successfully built: targets/nrf52_bno055_test

Step 4: Creating an Application Image
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Run the ``newt create-image`` command to create an image file. You may
assign an arbitrary version (e.g. 1.0.0) to the image.

.. code-block:: console


    $ newt create-image nrf52_bno055_test 1.0.0
    App image succesfully generated: ~/dev/myproj/bin/targets/nrf52_bno055_test/app/apps/sensors_test/sensors_test.img

Step 5: Connecting the BNO055 Sensor to the nRF52-DK Board
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Connect the pins from the BNO055 sensor to the nRF52-DK board as
specified in the following table:

+----------+--------------+----------------+
| Lines    | BNO055 Pin   | nRF52-DK Pin   |
+==========+==============+================+
| Power    | Vin          | 5V             |
+----------+--------------+----------------+
| Clock    | SCL          | P0.27          |
+----------+--------------+----------------+
| Data     | SDA          | P0.26          |
+----------+--------------+----------------+
| Ground   | GND          | GND            |
+----------+--------------+----------------+

|Alt Layout - BNO055| |Alt Layout - NRF52_I2C|

Step 6: Connecting the nRF52-DK Board to your Computer
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Set up two connections between your computer and the nRF52-DK board:

-  A serial connection to communicate with the sensors\_test application
   and view the sensor data and hardware information via the Mynewt
   shell.

   You can reference the :doc:`Serial Port
   Setup <../../get_started/serial_access>` tutorial for more
   information on setting up a serial communication.

-  A connection from your computer to the micro-USB port on the nRF52-DK
   board to power the board and to load the bootloader and application
   image.

2. Turn the power on the board to ON. You should see the green LED
light up on the board.

Step 7: Loading the Bootloader and the Application Image
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

1. Run the ``newt load nrf52_boot`` command to load the bootloader onto the board:

.. code-block:: console


    $ newt load nrf52_boot
    Loading bootloader
    $

2. Run the ``newt load nrf52_bno055_test`` command to load the
application image on to the board:

.. code-block:: console


    $ newt load nrf52_bno055_test
    Loading app image into slot 1
    $

3. Power the nRF52-DK board OFF and ON.

Step 8: Using a Terminal Emulator to Connect to the Application Console
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Start up a terminal emulator to connect the sensors\_test application
console. You can use one of the terminal emulators listed below or one
of your choice:

-  On Mac OS and Linux platforms, you can run
   ``minicom -D /dev/tty.usbserial-<port> -b 115200`` to connect to the
   console of your app. Note that on Linux, the format of the port name
   is ``/dev/ttyUSB<N>``, where N is a number.

-  On Windows, you can use a terminal application such as PuTTY to
   connect to the device.

   If you located your port from a MinGW terminal, the port name format
   is ``/dev/ttyS<N>``, where ``N`` is a number. You must map the port
   name to a Windows COM port: ``/dev/ttyS<N>`` maps to ``COM<N+1>``.
   For example, ``/dev/ttyS2`` maps to ``COM3``.

   You can also use the Windows Device Manager to locate the COM port.

We use minicom for this tutorial. After minicom connects, enter
<return> to ensure the shell is running. You should see the ``compat>``
prompt:

.. code-block:: console


    Welcome to minicom 2.7.1

    OPTIONS:
    Compiled on May 17 2017, 15:29:14.
    Port /dev/tty.usbserial, 13:55:21

    Press Meta-Z for help on special keys


    010674 compat>

Step 9: Viewing the Registered Sensors and Sensor Data
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The sensor framework package implements the ``sensor`` shell command. This command
allows you to:

-  List all the registered sensor devices.
-  View the sensor types that a registered sensor device supports.
-  Read sensor data samples.

To view the command syntax, enter ``sensor``

.. code-block:: console


    002340 Possible commands for sensor are:
    002341   list
    002341       list of sensors registered
    002342   read <sensor_name> <type> [-n nsamples] [-i poll_itvl(ms)] [-d poll_du]
    002344       read <no_of_samples> from sensor<sensor_name> of type:<type> at pr
    002347       at <poll_interval> rate for <poll_duration>
    002348   type <sensor_name>
    002349       types supported by registered sensor
    002350 compat>

Listing the Registered Sensors
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

You use the ``sensor list`` command to list all the registered sensor devices:

.. code-block:: console


    031798 compat> sensor list
    129441 sensor dev = bno055_0, configured type = 0x1 0x2 0x4 0x200 0x1000 0x2000
    129444 compat>

The output shows one sensor, **bno055\_0**, registered, and the
configured types for the sensor. A configure type is a subset of the
types that a sensor supports.

Listing the Types that a Sensor Supports
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

You use the ``sensor type`` command to list the types that a sensor
supports:

.. code-block:: console


    031822 compat> sensor type bno055_0
    033156 sensor dev = bno055_0,
    type =
    033157     accelerometer: 0x1
    033157     magnetic field: 0x2
    033158     gyroscope: 0x4
    033159     temperature: 0x10
    033160     vector: 0x200
    033160     accel: 0x1000
    033161     gravity: 0x2000
    033162     euler: 0x4000

Viewing Sensor Data Samples
^^^^^^^^^^^^^^^^^^^^^^^^^^^

You use the ``sensor read`` command to
read data samples for a configured type. You can specify the number of
samples to read, a poll interval, and a poll duration. You can only view
sensor data for the sensor types that a sensor device is configured for.

**Example 1:** Read 5 samples of accelerometer data from the
**bno055\_0** sensor:

.. code-block:: console


    033163 compat> sensor read bno055_0 0x1 -n 5
    042974 ts: [ secs: 335 usecs: 745441 cputime: 336218225 ]
    042976 x = -0.519999968 y = -7.289999968 z = 6.489999776
    042978 ts: [ secs: 335 usecs: 771216 cputime: 336244000 ]
    042979 x = -0.529999968 y = -7.360000128 z = 6.559999936
    042981 ts: [ secs: 335 usecs: 794640 cputime: 336267424 ]
    042982 x = -0.529999968 y = -7.340000160 z = 6.480000032
    042983 ts: [ secs: 335 usecs: 810795 cputime: 336283579 ]
    042984 x = -0.519999968 y = -7.300000192 z = 6.530000224
    042986 ts: [ secs: 335 usecs: 833703 cputime: 336306487 ]
    042987 x = -0.510000000 y = -7.309999936 z = 6.380000128

Each sample contains two lines of output. The first line is the time
when the sample is read. The second line is the sample data. For the
example output:

These two lines are for the first sample:

.. code-block:: console


    042974 ts: [ secs: 335 usecs: 745441 cputime: 336218225 ]
    042976 x = -0.519999968 y = -7.289999968 z = 6.489999776

These two lines are for the last sample:

.. code-block:: console


    042986 ts: [ secs: 335 usecs: 833703 cputime: 336306487 ]
    042987 x = -0.510000000 y = -7.309999936 z = 6.380000128

**Example 2:** Read the vector data at 20 ms poll interval. You can
enter ``ctrl-c``, ``q <return>``, or ``Q <return>`` to stop the polling.

.. code-block:: console

    002350 compat> sensor read bno055_0 0x200 -i 20
    019271 ts: [ secs: 150 usecs: 560056 cputime: 151019584 ]
    019272 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019274 ts: [ secs: 150 usecs: 580598 cputime: 151040126 ]
    019275 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019277 ts: [ secs: 150 usecs: 604036 cputime: 151063564 ]
    019278 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019280 ts: [ secs: 150 usecs: 627474 cputime: 151087002 ]
    019281 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019283 ts: [ secs: 150 usecs: 650912 cputime: 151110440 ]
    019284 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019286 ts: [ secs: 150 usecs: 674350 cputime: 151133878 ]
    019287 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019289 ts: [ secs: 150 usecs: 697788 cputime: 151157316 ]
    019290 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019292 ts: [ secs: 150 usecs: 721225 cputime: 151180753 ]
    019293 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019295 ts: [ secs: 150 usecs: 744663 cputime: 151204191 ]
    019296 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019298 ts: [ secs: 150 usecs: 768101 cputime: 151227629 ]
    019299 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984
    019301 ts: [ secs: 150 usecs: 791539 cputime: 151251067 ]
    019302 x = 3.442626944 y = 0.026977540 z = 3.993286144 w = 0.829833984

Step 10: Controlling and Viewing Sensor Device Hardware and Sensor Data
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The BNO055 device driver implements the ``bno055`` shell command
that allows you to:

-  Read sensor data samples for all the sensor types that the device
   supports.

   **Note:** The ``sensor`` shell command discussed previously only
   reads sensor data for configured sensor types.

-  Query the chip id, sensor revisions, content of registers, sensor
   offsets.
-  Reset the device.
-  Change the power mode.
-  Change the operation mode.

Enter ``bno055`` to see the command syntax:

.. code-block:: console


    711258 bno055 cmd  [flags...]
    711259 cmd:
    711259  r     [n_samples] [ 0-acc          | 1 -mag       | 2 -gyro    | 4 -tem|
                                9-quat         | 26-linearacc | 27-gravity | 28-eul]

    711264  mode  [0-config   | 1-acc          | 2 -mag       | 3 -gyro    | 4 -acc|
                   5-accgyro  | 6-maggyro      | 7 -amg       | 8 -imuplus | 9 -com|
                   9-m4g      |11-NDOF_FMC_OFF | 12-NDOF  ]
    711269  chip_id
    711270  rev
    711270  reset
    711270  pmode [0-normal   | 1-lowpower     | 2-suspend]
    711272  sensor_offsets
    711272  dumpreg [addr]

 \*\* Example 3: \*\* Query the device chip id:

.. code-block:: console


    711273 compat> bno055 chip_id
    769056 0xA0

**Example 4:** View the sensor revisions:

.. code-block:: console


    827472 compat> bno055 rev
    862354 accel_rev:0xFB
    mag_rev:0x32
    gyro_rev:0x0F
    sw_rev:0x311
    bl_rev:0x15

Next Steps
~~~~~~~~~~


Now that you have successfully enabled an application to communicate
with a sensor, We recommend that you:

-  Experiment with other ``sensor`` and ``bno055`` shell commands in
   this tutorial to view other types of sensor data.
-  Change the default configuration values for the sensor. See the
   :doc:`Changing the Default Configuration for a Sensor
   tutorial <sensor_offboard_config>`
-  Try a different off-board sensor. You can follow most of the
   procedures in this tutorial to enable other sensors in the
   sensors\_test application. The ``syscfg.yml`` file for the
   ``hw/sensor/creator/`` package specifies the off-board sensors that
   Mynewt currently supports. You will need to:

   -  Enable the ``<SENSORNAME>_OFB`` setting to include the sensor
      driver package and to create and initialize the sensor device.
   -  Enable the correct interface in the nRF52 BSP to communicate with
      the sensor device.
   -  Enable the sensor device driver shell command if the driver
      supports the shell. You can check the ``syscfg.yml`` file for the
      sensor device driver package in the
      ``hw/drivers/sensor/<sensorname>`` directory.

-  Try one of the other sensor tutorials listed in the :doc:`Sensor Tutorials
   Overview <sensors>`

.. |Alt Layout - BNO055| image:: ../pics/BNO055_small.jpg
.. |Alt Layout - NRF52_I2C| image:: ../pics/NRF52_I2C_small.jpg