Application module
Important
The Asset Tracker v2 application is in maintenance mode. For new projects, it is recommended to use the Cellular: nRF Cloud multi-service sample instead.
The application module controls key mechanisms in the Asset Tracker v2. It decides when to sample data, what types of data to sample, and has explicit control over some aspects of the application.
Features
This section documents the features implemented by the module.
Sample requests
Depending on the application’s Real-time configurations, the application module sends periodic sample requests to other modules in the system.
The sample requests are of type APP_EVT_DATA_GET and contains a list of Data types that must be sampled by the corresponding module.
Each module handles the sample requests individually and if a module finds its corresponding data type in the list, it starts sampling for that particular data type.
For instance, if the Location module finds the APP_DATA_LOCATION data type, it starts searching for a location.
Some modules, such as the Modem module, even support multiple data types.
It supports APP_DATA_MODEM_STATIC, APP_DATA_MODEM_DYNAMIC, and APP_DATA_BATTERY.
In addition to the sample list, the module also includes a sample timeout in the APP_EVT_DATA_GET event.
This timeout sets how much time each module has to sample data before the Data module sends what is available.
Note
Sample requests are sent either periodically or upon detection of movement. The timeouts and modes that have an impact on the frequency of sample requests are documented in Real-time configurations.
Application start
The application module is the system’s initial point of entry and the source file of the module is asset_tracker_v2/src/main.c.
When the application boots, the module initializes the Application Event Manager and sends out the initial event APP_EVT_START that starts the rest of the modules in the application.
It also initializes the Common Application Framework overview by calling the module_set_state() API with the MODULE_STATE_READY state.
Configuration options
There are no configuration options for the application module.
Module states
The application module has an internal state machine with the following states:
STATE_INIT- The initial state of the module.STATE_RUNNING- The module has received its initial configuration from the data module and has started the appropriate timers.SUB_STATE_ACTIVE_MODE- The application is in the active mode. In this state, the module sends out sample requests periodically.SUB_STATE_PASSIVE_MODE- The application is in the passive mode. In this state, the module sends out a sample request upon movement.
STATE_SHUTDOWN- The module has been shut down after receiving a request from the utility module.
Module events
The asset_tracker_v2/src/events/app_module_event.h header file contains a list of events sent by the module.
Dependencies
This module uses the following nRF Connect SDK libraries and drivers:
API documentation
asset_tracker_v2/src/events/app_module_event.hasset_tracker_v2/src/events/app_module_event.c, asset_tracker_v2/src/main.c