.. zephyr:code-sample:: alarm
:name: Counter Alarm
:relevant-api: counter_interface
Implement an alarm application using the counter API.
Overview
********
This sample provides an example of alarm application using :ref:`counter API <counter_api>`.
It sets an alarm with an initial delay of 2 seconds. At each alarm
expiry, a new alarm is configured with a delay multiplied by 2.
.. note::
In case of 1Hz frequency (RTC for example), precision is 1 second.
Therefore, the sample output may differ in 1 second
Requirements
************
This sample requires the support of a timer IP compatible with alarm setting.
References
**********
- :ref:`disco_l475_iot1_board`
Building and Running
********************
.. zephyr-app-commands::
:zephyr-app: samples/drivers/counter/alarm
:host-os: unix
:board: disco_l475_iot1
:goals: run
:compact:
Sample Output
=============
.. code-block:: console
Counter alarm sample
Set alarm in 2 sec
!!! Alarm !!!
Now: 2
Set alarm in 4 sec
!!! Alarm !!!
Now: 6
Set alarm in 8 sec
!!! Alarm !!!
Now: 14
Set alarm in 16 sec
!!! Alarm !!!
Now: 30
<repeats endlessly>
44e72ab024