Module humidity

Async Humidity Sensor API

This API provides generic methods for interfacing with humidity sensors specifically.

For HAL authors

Here is an example for the implementation of the RelativeHumiditySensor and RelativityHumidityThresholdWait traits for a humidity sensor.

use embedded_sensors_hal_async::sensor;
use embedded_sensors_hal_async::humidity::{
    Percentage, RelativeHumidityHysteresis, RelativeHumiditySensor,
    RelativeHumidityThresholdSet, RelativeHumidityThresholdWait,
};

// A struct representing a humidity sensor.
pub struct MyHumiditySensor {
    // ...
}

#[derive(Clone, Copy, Debug)]
pub enum Error {
    // ...
}

impl sensor::Error for Error {
    fn kind(&self) -> sensor::ErrorKind {
        match *self {
            // ...
        }
    }
}

impl sensor::ErrorType for MyHumiditySensor {
    type Error = Error;
}

impl RelativeHumiditySensor for MyHumiditySensor {
    async fn relative_humidity(&mut self) -> Result<Percentage, Self::Error> {
        // ...
        Ok(42.0)
    }
}

impl RelativeHumidityThresholdSet for MyHumiditySensor {
    async fn set_relative_humidity_threshold_low(
        &mut self,
        threshold: Percentage
    ) -> Result<(), Self::Error> {
        // Write value to threshold low register of sensor...
        Ok(())
    }

    async fn set_relative_humidity_threshold_high(
        &mut self,
        threshold: Percentage
    ) -> Result<(), Self::Error> {
        // Write value to threshold high register of sensor...
        Ok(())
    }
}

impl RelativeHumidityThresholdWait for MyHumiditySensor {
    async fn wait_for_relative_humidity_threshold(
        &mut self,
    ) -> Result<Percentage, Self::Error> {
        // Await threshold alert (e.g. await GPIO level change on ALERT pin)...
        // Then return current relative humidity so caller can determine which threshold was crossed
        self.relative_humidity().await
    }
}

impl RelativeHumidityHysteresis for MyHumiditySensor {
    async fn set_relative_humidity_threshold_hysteresis(
        &mut self,
        hysteresis: Percentage
    ) -> Result<(), Self::Error> {
        // Write value to threshold hysteresis register of sensor...
        Ok(())
    }
}

Traits

RelativeHumidityHysteresis

Asynchronously set RelativeHumidity threshold hysteresis.

RelativeHumiditySensor

Async Relative Humidity Sensor methods.

RelativeHumidityThresholdSet

Asynchronously set RelativeHumidity thresholds.

RelativeHumidityThresholdWait

Asynchronously wait for RelativeHumidity measurements to exceed specified thresholds.

Type Aliases

Percentage

Associates the units relative humidity (RH) samples are measured in with the underlying data type.