# Lib SCD

[](https://crates.io/crates/libscd)
[](https://crates.io/crates/libscd)
[](https://github.com/SvetlinZarev/libscd/actions)
LibSCD is s Rust driver implementation for SCD30, SCD40 and SCD41 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:
```toml
[dependencies.libscd]
version = "0.3"
features = ["defmt", "sync", "scd40"]
```
Then we can start consuming data from SCD40 using blocking I2C communication:
```rust
#[embassy_executor::main]
async fn main(_spawner: Spawner) {
let p = embassy_stm32::init(Default::default());
let i2c = I2c::new(
p.I2C2,
p.PB10,
p.PB3,
Irqs,
NoDma,
NoDma,
Hertz(100_000),
Default::default(),
);
let mut scd = Scd40::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)
}
}
```
## Crate Feature Flags
The support for each sensor and sync/async mode is controlled by a feature:
| sync | Enables the blocking driver implementation for the selected sensors |
| async | Enables the async driver implementation for the selected sensors |
| scd30 | Enables the driver for the SCD30 sensor |
| scd40 | Enables the driver for the SCD40 sensor |
| scd41 | Enables the driver for the SCD41 sensor |
| defmt | Derive `defmt::Format` for the error type |
## License
The project is dual licensed under [MIT](https://opensource.org/licenses/MIT)
or [APACHE-2.0](https://opensource.org/licenses/Apache-2.0)