samples/sensor/adxl372/README.rst

.. _adxl372:

ADXL372: Three Axis High-g I2C/SPI Accelerometer
################################################

Description
***********

This sample application produces slightly different outputs based on the chosen
driver configuration mode:

* In **Measuring Mode with trigger support**,
  the acceleration on all three axis is printed in m/s^2 at the sampling rate (ODR).
* In **Polled Measuring Mode**, the instantaneous acceleration is polled every 2 seconds.
* In **Max Peak Detect Mode**, the device returns only the over-threshold
  peak acceleration between two consecutive sample fetches or trigger events.
  (In most high-g applications, a single 3-axis acceleration sample at the peak
  of an impact event contains sufficient information about the event, and the
  full acceleration history is not required.) Instead of printing the acceleration
  on all three axis, the sample application calculates the vector magnitude
  (root sum squared) and displays the result in g's rather than in m/s^2,
  together with an bar graph.


References
**********

- ADXL372: http://www.analog.com/adxl372

Wiring
*******

This sample uses the ADXL372 sensor controlled either using the I2C or SPI interface.
Connect supply **VDD**, **VS** and **GND**. The supply voltage can be in
the 1.6V to 3.5V range.

I2C mode
========

Connect Interface: **SDA**, **SCL** and optionally connect the **INT1** to a
interrupt capable GPIO. It is a requirement that **SCLK** must be connected to
**GND** in I2C mode. Depending on the baseboard used, the **SDA** and **SCL**
lines require Pull-Up resistors. With the **MISO** pin low, the I2C address for
the device is 0x1D, and an alternate I2C address of 0x53 can be chosen by
pulling the **MISO** pin high.

I2C Address:

* **0x1D**: if MISO is pulled low
* **0x53**: if MISO is pulled high

.. Note::
   When sharing an SDA bus, the ADXL372 Silicon Revision < 3  may prevent
   communication with other devices on that bus.

SPI mode
========

Connect Interface: **SCLK**, **MISO**, **MOSI** and **/CS** and optionally
connect the **INT1** to a interrupt capable GPIO.


Building and Running
********************

This project outputs sensor data to the console. It requires an ADXL372
sensor. It should work with any platform featuring a I2C/SPI peripheral interface.
It does not work on QEMU.
In this example below the :ref:`nrf52dk_nrf52832` board is used.


.. zephyr-app-commands::
   :zephyr-app: samples/sensor/adxl372
   :board: nrf52dk_nrf52832
   :goals: build flash


Sample Output: Max Peak Detect Mode
===================================

.. code-block:: console

   Waiting for a threshold event
    23.94 g: ########################
   Waiting for a threshold event
    38.01 g: #######################################
   Waiting for a threshold event
    51.40 g: ####################################################
   Waiting for a threshold event
    63.63 g: ################################################################

Sample Output: Measurement Mode
===============================

.. code-block:: console

   AX=      2.94 AY=     -5.88 AZ=      0.98 (m/s^2)
   AX=     -4.90 AY=      6.86 AZ=     -1.96 (m/s^2)
   AX=      2.94 AY=     -2.94 AZ=      8.83 (m/s^2)
   AX=     -0.98 AY=     -6.86 AZ=     -0.98 (m/s^2)
   AX=      6.86 AY=      2.94 AZ=      3.92 (m/s^2)
   AX=     -0.98 AY=      4.90 AZ=     -3.92 (m/s^2)

   <repeats endlessly>