Struct mhz19::MHZ19

pub struct MHZ19 { /* fields omitted */ }

mh-z19 CO₂ sensor

Usage

use mhz19::MHZ19;

fn main() {
    let mut mhz19 = MHZ19::open("/dev/ttyUSB0").unwrap();
    println!("CO₂ readout: {} ppm", mhz19.read().unwrap());
}

Methods

impl MHZ19

pub fn open<T: AsRef<OsStr> + ?Sized>(port: &T) -> Result<Self>

Connect to the mh-z19 at the specified serial port

pub fn read(&mut self) -> Result<u16>

Read the CO2 value from the meter as ppm

Blocking

This command will wait for 100ms between sending the read command and getting the response during this the thread is blocked

If the crc check of the response fails the method will retry up to 8 times

pub fn zero_calibrate(&mut self) -> Result<()>

Tell the mh-z19 to zero-point calibrate

Sensor should be at 400ppm when calibrating

pub fn span_calibrate(&mut self, value: u16) -> Result<()>

Tell the mh-z19 to span-point calibrate

Sensor should be at target level when calibrating

pub fn enable_abc(&mut self, enable: bool) -> Result<()>

Enable or disable automatic baseline correction

Automatic baseline correction will automatically adjust the baseline value every 24h after power on to the "standard" value of 400ppm based on the lowest values measured each cycle.

This is suitable for situations like home or office buildings where no people are present for multiple hours each day allowing the CO₂ values to come down to outside levels

For units produced after 2015 this should be enabled by default

pub fn set_range(&mut self, range: Range) -> Result<()>

Set the detection range for the sensor

A range of 2000ppm or 5000ppm is supported