Lib SCD

LibSCD is s Rust driver implementation for SCD30, SCD40, SCD41 and SCD43 sensors using the embedded-hal and embedded-hal-async interfaces.

Usage

Add the crate as a dependency in Cargo.toml and select the required features:

[dependencies.libscd]
version = "0.5"
features = ["defmt", "sync", "scd4x"]

Then we can start consuming data from SCD4x using blocking I2C communication:

#[embassy_executor::main]
async fn main(_spawner: Spawner) {
    let p = embassy_stm32::init(Default::default());
    let i2c = I2c::new_blocking(
        p.I2C2,
        p.PB10,
        p.PB3,
        Hertz(100_000),
        Default::default(),
    );

    let mut scd = Scd4x::new(i2c, Delay);

    // When re-programming, the controller will be restarted,
    // but not the sensor. We try to stop it in order to
    // prevent the rest of the commands failing.
    _ = scd.stop_periodic_measurement();

    info!("Sensor serial number: {:?}", scd.serial_number());
    if let Err(e) = scd.start_periodic_measurement() {
        defmt::panic!("Failed to start periodic measurement: {:?}", e);
    }

    loop {
        if scd.data_ready().unwrap() {
            let m = scd.read_measurement().unwrap();
            info!("CO2: {}\nHumidity: {}\nTemperature: {}", m.co2, m.humidity, m.temperature)
        }

        Delay.delay_ms(1000)
    }
}

Migrating from v0.4

Version 0.5 contains breaking changes:

• The SCD4x family of sensors are exposed via common type - SCD4x. The old structures are no longer available.
• The scd40 crate feature is renamed to scd4x
• SCD4x use HPa instead of Pa for setting/getting the ambient pressure
• The Measurement type is no longer reexported by each sensor. The common shared type should be used instead.

Crate Feature Flags

The support for each sensor and sync/async mode is controlled by a feature:

License

The project is licensed under MIT license