Application Event Manager profiling tracer

The Application Event Manager profiling tracer sample demonstrates the functionality of profiling Application Event Manager events using the nRF Profiler and the Application Event Manager profiler tracer modules.

Requirements

The sample supports the following development kits:

Hardware platforms

PCA

Board name

Build target

nRF9160 DK

PCA10090

nrf9160dk_nrf9160

nrf9160dk_nrf9160_ns

nRF52 DK

PCA10040

nrf52dk_nrf52832

nrf52dk_nrf52832

nRF52840 DK

PCA10056

nrf52840dk_nrf52840

nrf52840dk_nrf52840

nRF21540 DK

PCA10112

nrf21540dk_nrf52840

nrf21540dk_nrf52840

Overview

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

  • Module A (module_a.c)

  • Module B (module_b.c)

Module A waits for a configuration event sent by 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 one_sec_event is sent. The counter value is transmitted during the event.

Module B waits for the one_sec_event events from Module A. Every time it receives a 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 five_sec_event to Module A.

When Module A receives a five_sec_event from Module B, it zeros the counter, sends a series of 50 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

See Configuring your application for information about how to permanently or temporarily change the configuration.

Building and running

This sample can be found under samples/app_event_manager_profiler_tracer in the nRF Connect SDK folder structure.

See Building and programming an application for information about how to build and program the application and Testing and debugging an application for general information about testing and debugging in the nRF Connect SDK.

Testing

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

  1. Run the script real_time_plot.py located in the 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 test_name.csv and a test_name.json file using the test_name argument:

    real_time_plot.py test_name

    The script opens a GUI window that displays events as points on timelines, similar to the following:

    Example of nRF Profiler backend script visualization

    Example of nRF Profiler backend script visualization

  2. Use scroll wheel to zoom into interesting parts on a GUI. See the Backend visualization in the Profiler documentation for more information about how to work with the diagram.

  3. Click the middle mouse button to highlight an event submission or processing for tracking, and to display the event data as on a figure:

    Diagram of GUI output zoomed in

    Sample diagram of zoomed-in GUI output

    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.

  4. Check the results for the generated test_name.csv and test_name.json files.

  5. See how events are logged with data transmitted by the event.

Dependencies

This sample uses the following nRF Connect SDK subsystems:

In addition, it uses the following Zephyr subsystems: