humidity sensors (original) (raw)

A cargo library for the SHT31 temperature / humidity sensors

Usage

The default sensor usage includes a blocking sensor read that blocks the current thread until the sensor does a reading.

use sht31::prelude::*;

fn main() -> Result<()> { // Requires an i2c connection + delay (both from embedded_hal 1.x.x) let sht = SHT31::new(i2c, delay);

loop {
    let reading = sht.read()?;
}

}

Advanced Single Shot Usage

Breaks down the simple usage into two commands, one where the sensor is notified to start reading and another where the reading is requested

use sht31::prelude::*;

fn main() -> Result<()> { // i2c setup

// Use single shot, with high accuracy, an alternate I2C address 
// and return temp data in Fahrenheit
let sht = SHT31::single_shot(i2c, SingleShot::new())
    .with_accuracy(Accuracy::High)
    .with_unit(TemperatureUnit::Fahrenheit)
    .with_address(DeviceAddr::AD1);

loop {
    // Start measuring before you need the reading, 
    // this is more efficient than waiting for readings
    sht.measure()?;

    // Some other code here...

    let reading = sht.read()?;
}

}

Periodic Usage

Periodic mode continually reads data at a rate of the given measurements per second (MPS) and at a quality of the given Accuracy. This means that you dont have to worry about running SHT31::measure() every time you want to read data

use sht31::prelude::*;

fn main() -> Result<()> { // i2c setup

// In periodic mode, the sensor keeps updating the reading
// without needing to measure
let mut sht = SHT31::periodic(
    i2c, 
    Periodic::new().with_mps(MPS::Normal)
)
    .with_accuracy(Accuracy::High);

// Trigger the measure before running your loop to initialize the periodic mode
sht.measure()?;

loop {
    let reading = sht.read()?;
}

}

Periodic with Accelerated Response Time

Periodic mode has a unique mode that allows the sensor to read data at 4Hz

use sht31::prelude::*;

fn main() -> Result<()> {

// Makes the sensor acquire the data at 4 Hz
let mut sht = SHT31::periodic(i2c, Periodic::new().with_art());
sht.measure()?;

loop {
    let reading = sht.read()?;
}

}

Mode switching

This crate also supports more complex case scenarios where you might want to switch between period to single shot for example

use sht31::prelude::*;

fn main() -> Result<()> { // i2c setup

let mut sht = SHT31::periodic(i2c, Periodic::new());

// Trigger the measure before running your loop to initialize the periodic mode
sht.measure()?;

// Do a periodic read
let reading = sht.read()?;

// Cancel the currently running command (periodic)
sht.break_command()?;

sht = sht.with_mode(SingleShot::new());

sht.measure()?;

let new_reading = sht.read()?;

}