Crate sgp40

Platform agnostic Rust driver for Sensirion SGP40 device with gas, temperature and humidity sensors based on the embedded-hal traits.

Sensirion SGP40

Sensirion SGP40 is a low-power accurate gas sensor for air quality application. The sensor has different sampling rates to optimize power-consumption per application bases as well as ability save and set the baseline for faster start-up accuracy. The sensor uses I²C interface and measures TVOC (Total Volatile Organic Compounds)

Datasheet: https://www.sensirion.com/file/datasheet_sgp40

Usage

Instantiating

Import this crate and an embedded_hal implementation, then instantiate the device:

use linux_embedded_hal as hal;

use hal::{Delay, I2cdev};
use sgp40::Sgp40;

let dev = I2cdev::new("/dev/i2c-1").unwrap();
let mut sgp = Sgp40::new(dev, 0x59, Delay);

Doing Measurements

The device is doing measurements independently of the driver and calls to the device will just fetch the latest information making the usage easy.

use linux_embedded_hal as hal;
use hal::{Delay, I2cdev};

use std::time::Duration;
use std::thread;

use sgp40::Sgp40;

let dev = I2cdev::new("/dev/i2c-1").unwrap();

let mut sensor = Sgp40::new(dev, 0x59, Delay);

// Discard the first 45 samples as the algorithm is just warming up.
for _ in 1..45 {
    sensor.measure_voc_index().unwrap();
}

loop {
    if let Ok(result) = sensor.measure_voc_index() {
        println!("VOC index: {}", result);
    }
    else {
        println!("Failed I2C reading");
    }

    thread::sleep(Duration::new(1_u64, 0));
}

VOC Index calculation

VOC index calculation is not no-std proof right now so if this is a problem for you, then you want to turn the feature off by turning “the defaults off”. Work for no-std index calculation will start soon.

Structs

Sgp40

Sgp40 driver instance

Enums

Error

Sgp40 errors