Crate embedded_qmp6988 

embedded-qmp6988

This is a platform agnostic Rust driver the QMP6988 digital barometric pressure sensor using the embedded-hal and embedded-hal-async traits.

This driver can be used both synchronously or asynchronously. It defaults to the synchronous implementation, but you can switch to the asynchronous one by using the async feature.

The device

The QMP6988 sensors is high accuracy and small size barometric pressure sensor with low current consumption.

It can be addressed through an I²C or an SPI interface. This driver uses the I²C interface.

Documentation:

• Datasheet
• C++ driver example

Features

• Choose the oversampling setting used for measurements.
• Choose the IIR filter used to reduce the noise in the measurements.
• Perform a single measurement (using the force power mode).
• Do a sofware set.
• Perform repeated measurements using the normal power mode.

Usage

To use this driver, import what you need from this crate and an embedded-hal implementation, then instantiate the device.

#[cfg(target_os = "linux")]
mod linux {
    use embedded_qmp6988::{IirFilter, OverSamplingSetting, Qmp6988, Temperature, DEFAULT_I2C_ADDRESS};
    use linux_embedded_hal as hal;

    pub fn main() -> Result<(), embedded_qmp6988::Error<hal::I2CError>> {
        // Create the I2C device from the chosen embedded-hal implementation,
        // in this case linux-embedded-hal
        let mut i2c = match hal::I2cdev::new("/dev/i2c-1") {
            Err(err) => {
                eprintln!("Could not create I2C device: {}", err);
                std::process::exit(1);
            }
            Ok(i2c) => i2c,
        };
        if let Err(err) = i2c.set_slave_address(DEFAULT_I2C_ADDRESS as u16) {
            eprintln!("Could not set I2C slave address: {}", err);
            std::process::exit(1);
        }

        // Create the sensor and configure its repeatability
        let mut sensor = Qmp6988::new(i2c, DEFAULT_I2C_ADDRESS, hal::Delay {})?;
        sensor.set_filter(IirFilter::Off)?;
        sensor.set_oversampling_setting(OverSamplingSetting::HighSpeed)?;

        // Perform a barometric pressure measurement
        let measurement = sensor.measure()?;
        println!(
            "Pressure: {:.2} hPa, Temperature: {:.2} °C",
            measurement.barometric_pressure.value(),
            measurement.temperature.celsius().value()
        );
        Ok(())
    }
}

fn main() {
    #[cfg(target_os = "linux")]
    linux::main();
    #[cfg(not(target_os = "linux"))]
    println!("This example only works on Linux");
}

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Structs

Qmp6988

QMP6988 device driver

Enums

Error

All possible errors generated when using the Qmp6988 struct

IirFilter

IIR (Infinite Impulse Response) filter.

OverSamplingSetting

The oversampling setting.

Constants

DEFAULT_I2C_ADDRESS

The default I2C address (SDO pin connected to low)

I2C_ADDRESS_LOGIC_HIGH

The I2C address when the SDO pin is connected to logic high

I2C_ADDRESS_LOGIC_LOW

The I2C address when the SDO pin is connected to logic low

Traits

Temperature

Trait defining the different ways to get a temperature.