Environmental module

The Environmental module collects sensor data from the onboard BME680 environmental sensor on the Thingy:91 X. The module provides temperature, pressure, and humidity readings to other modules through the zbus messaging system. The module initializes the sensor hardware and responds to sampling requests from the main application module.

To initiate a sensor reading, the main module sends an ENVIRONMENTAL_SENSOR_SAMPLE_REQUEST message to the environmental module. The environmental module then reads the sensor data and sends an ENVIRONMENTAL_SENSOR_SAMPLE_RESPONSE message with the collected data asynchronously.

Messages

The Environmental module communicates via the zbus channel ENVIRONMENTAL_CHAN, using message types defined in environmental.h.

Input Messages

• ENVIRONMENTAL_SENSOR_SAMPLE_REQUEST Requests the module to take new sensor readings from the environmental sensor.

Output Messages

• ENVIRONMENTAL_SENSOR_SAMPLE_RESPONSE Returns collected environmental data with the following fields:
  • temperature: Temperature value in degrees Celsius
  • pressure: Atmospheric pressure in Pascals
  • humidity: Relative humidity percentage

The message structure used by the environmental module is defined in environmental.h:

struct environmental_msg {
    enum environmental_msg_type type;
    double temperature;
    double pressure;
    double humidity;
};

Configurations

The Environmental module can be configured using the following Kconfig options:

• CONFIG_APP_ENVIRONMENTAL Enables the Environmental module.

• CONFIG_APP_ENVIRONMENTAL_THREAD_STACK_SIZE Size of the stack for the environmental module’s thread.

• CONFIG_APP_ENVIRONMENTAL_WATCHDOG_TIMEOUT_SECONDS Defines the watchdog timeout for the environmental module.

• CONFIG_APP_ENVIRONMENTAL_MSG_PROCESSING_TIMEOUT_SECONDS Maximum time allowed for processing a single message.

• CONFIG_APP_ENVIRONMENTAL_LOG_LEVEL_INF/_ERR/_WRN/_DBG Controls logging level for the environmental module.

For more details on Kconfig options, see the Kconfig.environmental file in the module’s directory.

State diagram

The environmental module implements a very simple state machine with only one state:

stateDiagram-v2
    [*] --> STATE_RUNNING