.. _lps22hh_i3c:

LPS22HH: Temperature and Pressure Monitor (I3C)
###############################################

Overview
********
This sample periodically reads pressure from the LPS22HH MEMS pressure
sensor and displays it on the console.

Requirements
************

This sample uses the LPS22HH sensor controlled using the I3C interface.
It has been tested using the LPS22HH on the evaluation board
STEVALMKI192-V1 connected to the I3C header on :ref:`mimxrt685_evk`.

References
**********

- LPS22HH: https://www.st.com/en/mems-and-sensors/lps22hh.html

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

This project outputs sensor data to the console. It requires an LPS22HH
sensor (for example, the one on evaluation board STEVALMKI192-V1).

.. note::

   If ``CONFIG_LPS22HH_TRIGGER`` is enabled, the trigger is using
   I3C In-Band Interrupt (IBI) to signal new data being available.
   Since IBI is initiated by the sensor, it will take over the I3C
   bus. Therefore, when flashing a new image, a power cycle is needed
   to reset the sensor so that it will not generate IBIs anymore.
   Or else the I3C controller will not be able to be initialized,
   resulting in the sample not being able to communicate with
   the sensor.

Building on mimxrt685_evk board
====================================

.. zephyr-app-commands::
   :zephyr-app: samples/sensor/lps22hh_i3c
   :host-os: unix
   :board: mimxrt685_evk/mimxrt685s/cm33
   :goals: build
   :compact:

Board Preparations
==================

mimxrt685_evk
------------------

On the board :ref:`mimxrt685_evk`, the I3C pins are exposed on the J18
header, where:

  * SCL is on pin 1
  * SDA is on pin 2
  * Internal pull-up is on pin 3 (which is connected to pin 2 already)
  * Ground is on pin4

LPS22HH
^^^^^^^

A LPS22HH sensor needs to be connected to this header. For example,
the evaluation board STEVAL-MKI192V1 can be used. This needs to be
prepared so that the LPS22HH sensor has address 0x5D (i.e. 0xBA,
left-shifed).

Sample Output
=============

.. code-block:: console

   Configured for triggered collection at 1 Hz
   Observation: 1
   Pressure: 97.474 kPa
   Temperature: 22.19 C
   Observation: 2
   Pressure: 97.466 kPa
   Temperature: 22.21 C
   Observation: 3
   Pressure: 97.473 kPa
   Temperature: 22.21 C
   Observation: 4
   Pressure: 97.455 kPa
   Temperature: 22.21 C

   <repeats endlessly every second>