Name	Name	Last commit message	Last commit date
parent directory ..
src	src
CMakeLists.txt	CMakeLists.txt
README.rst	README.rst
prj.conf	prj.conf
sample.yaml	sample.yaml

Application Event Manager profiling tracer

Requirements
Overview
Configuration
Building and running
- Testing
Dependencies

The Application Event Manager profiling tracer sample demonstrates the functionality of profiling :ref:`app_event_manager` events using the :ref:`nrf_profiler` and the :ref:`app_event_manager_profiler_tracer` modules.

Requirements

The sample supports the following development kits:

.. table-from-sample-yaml::

Overview

The sample application consists of the following modules that communicate using events:

Module A (:file:`module_a.c`)
Module B (:file:`module_b.c`)

Module A waits for a configuration event sent by :file:`main.c`. After receiving this event, Module A starts sending periodic events every second to Module B. Module A also has a counter that increases before a :c:struct:`one_sec_event` is sent. The counter value is transmitted during the event.

Module B waits for the :c:struct:`one_sec_event` events from Module A. Every time it receives a :c:struct:`one_sec_event`, the module checks if the value it transmits is equal to 5. If it is equal to 5, Module B sends a :c:struct:`five_sec_event` to Module A.

When Module A receives a :c:struct:`five_sec_event` from Module B, it zeros the counter, sends a series of 50 :c:struct:`burst_event`, and simulates work for 100 ms by busy waiting.

.. msc::
   hscale = "1.3";
   Main [label="main.c"],ModA [label="Module A"],ModB [label="Module B"];
   Main>>ModA [label="Configuration event"];
   ModA rbox ModA [label="Increases the counter"];
   ModA>>ModB [label="One-second event, counter value 1"];
   ModB rbox ModB [label="Checks the counter"];
   ModA rbox ModA [label="Increases the counter"];
   ModA>>ModB [label="One-second event, counter value 2"];
   ModB rbox ModB [label="Checks the counter"];
   |||;
   ...;
   ...;
   |||;
   ModA rbox ModA [label="Increases the counter"];
   ModA>>ModB [label="One-second event, counter value 5"];
   ModB rbox ModB [label="Checks the counter\nCounter value matches 5"];
   ModA<<ModB [label="Five-second event"];
   ModA rbox ModA [label="Zeroes the counter\nSends 50 burst events\nSimulates work for 100 ms"];

Configuration

|config|

Building and running

Testing

After programming the sample to your development kit, test it by performing the following steps:

Run the script :file:`real_time_plot.py` located in the :file:`scripts/nrf_profiler` folder, with the name that is to be used to store the data as argument. For example, run the following command to generate a :file:`test_name.csv` and a :file:`test_name.json` file using the test_name argument:
```
python3 real_time_plot.py *test_name*
```
The script opens a GUI window that displays events as points on timelines, similar to the following:

nRF Profiler host tools GUI window
Use the scroll wheel to zoom into interesting parts on a plot. See the :ref:`nrf_profiler_script_visualization_GUI` section in the nRF Profiler host tools documentation for more information about how to navigate in the GUI window.
Click the middle mouse button to highlight an event submission or processing for tracking, and to display the event data as on a figure:

nRF Profiler host tools GUI window zoomed in

On this image, the zoom focuses on actions triggered by the fifth one-second event. The five-second event triggers 50 burst events. One event submission and corresponding processing time is highlighted in green.
Check the results for the generated :file:`test_name.csv` and :file:`test_name.json` files. See how events are logged with data transmitted by the event.
Calculate the nRF Profiler event propagation statistics (statistics for time intervals between nRF Profiler events) from the previously collected dataset using the following command:
```
python3 calc_stats.py *test_name* stats_nordic_presets/app_event_manager_profiler_tracer.json
```
The :file:`stats_nordic_presets/app_event_manager_profiler_tracer.json` file specifies the nRF Profiler events used for the calculations. The file refers to the events used by the sample. See the :ref:`nrf_profiler_script_calculating_statistics` section in the nRF Profiler host tools documentation for more information.